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|RWD FORD AOD TRANSMISSION PARTS
Submitted by macx / 09-10-04
Much of this applies to all three types of
transmissions, some to AOD only &
are noted as such. I have compiled this through lots of research
while rebuilding my own and lots of other sources. There is lots
of into to be found at www.tccoa.com -
on their home page is their Tech Articles section. Go to the transmission
articles, the first in the list is "trans 101", refer to it for more details - lots of good info
in their other transmission articles. Also lots of info here from www.baumannengineering.com
(changing to www.becontrols.com). DEFINITELY READ the information on both of these sites!!!!
I have tried to be careful to get the information correct, but the usual "no guarantees" -
check for yourself!
See www.fordpartsnetwork.com for decent discounts on genuine ford parts.
Check www.oemfordparts.com and Ford Racing for information on high performance
Ford parts and part numbers.
BACKGROUND & IDENTIFICATION
For an excellent schematic and parts breakdown and listing by year and type,
. (You might have to register at the home page, but it's free).
- AOD's were made from '80 - '93.
- AOD/E's were made from '92 - '95 ('94-'95 Mustang, Crown Vic, Grand Marquis,
and '92 -'94 Town Car only.
- 4R70W's were made from '93 up and in '94 - '95 T-Birds & F and E trucks,
and '93 - '95 (all) Mark VIII's. '98 and up had a different shift lever sensor
which must match to the '98 & up control. '93 and up have N-OD-2-1 shift
pattern & manual selection of all gears.
- Pre-'88's had accumulator problems - with late or no shifts,
or shudder on 1-2 shifts. AOD’s have no 1-2 accumulator
piston, but have a 1-2 accumulator valve in the valve body.
Check becontrols.com or Art Carr or Sonnax for the cure, including
- V6 AOD/E's & 3.8 V6 4R70W's have just 1 less direct clutch
plate than the V8 transmissions which are easily added. Both
bolt to Windsor V8's, but are only in light trucks and have
to have the manual shift lever shaft changed to one from a car
transmission so the lever points down for a car application.
This is easily done by removing the pan and pulling a roll pin.
- 4.2 V6 & all V8 4R70W's have the same number of direct
clutch plates. 4.2 transmissions bolt to Windsor V8's.
- Police transmissions have the same internal parts, and are not heavier
duty than other models.
- Some AOD's & AOD/E's had longer tail shafts and housings,
and so won't directly exchange with standard length units or
swap directly for C4's (because of resultant drive shaft length
changes) into older cars like the standard length units. The
longer ones are mostly in Lincolns and some trucks, also Town
Cars and police cars.
- Standard length AOD/Es and 4R70Ws are 7/8” longer than standard
length AODs. Long length AOD’s are 1”
longer than standard length AOD's, so standard length AOD/E's and 4R70Ws
are just 1/8” shorter than long length AODs (such as in
Lincoln Mark VII's).
- Some AOD/E's and all the 4R70Ws also have larger diameter
output shaft bushings & larger diameter yokes. The larger
diameter 4R70W yoke was made for higher horsepower capacity.
All models have the same 28 spline output shaft profile, so
small bushing tail shaft housings can be swapped. This is also
the same as C-4 transmissions which makes swaps easy.
- Markings on tail shaft housings: Large bushing standard length F3LP. Large
bushing long length F3UP. Small bushing standard length F2TP or EOAP. Small
bushing long length EOTP or EOLP.
- Stock AODs have a quite low stall speed.
- AOD/E's and 4R70W's have a higher stock stall speed.
- You can only use a 12" 4R70W converter on Windsor V8's, the 11" 4.6
converters won't fit the Windsor flex plate.
- The best (highest stall) 12" AOD/E to use is from 5.0 engines, and
4R70W most 3.8 V6 Mustangs F85Z-7902-AARM. However, they're only good to
5400 rpm before they start to balloon and destruct. There is also a 12” police
converter that is higher lockup –
2200 to 2600 with stock 5.0’s or higher with engines that have more
torque in the 2k to 3k range – and they have heavy
duty lockup clutches. Roadrunner Converters rebuilds them
with improvements to durability and a higher anti-ballooning
limit from the stock 5400 rpm to 6200 rpm for only around
$200 as of 7/05.
- Also, pre-'95, or Mark VIII & Mustang converters thru
'97 have inferior lockup clutch friction materials and the
lock-up plates are not as stiff as later ones. For any increase
in stall or higher rpm range, you generally need to go aftermarket
(other than the Roadrunner Converter). BUT stay with good
name brands. Cheap converters have durability problems and
lose torque multiplication. According to posts on Mustang
forums such as www.corral.net, you can use a stock V6 lockup
converter with no durability problems on plain AOD's for
a cheap stall speed increase of several hundred rpm. Some
good ones for AOD's are from www.baumannengineering.com,
www.artcarr.com, www.converter.com (Precision), also www.levelten.com
and Pro-Torque. I'm sure there are others. Also check www.lentechautomatics.com
for their popular street terminator valve bodies and lockup
converters for AOD's.
- If you use a non-lockup converter for an AOD, you have only 90 to 95% power
transfer in upper gears and are actually losing acceleration because of that.
Good quality, higher stall stock diameter lockup converters start about $300.Lentech
has smaller lockups, check with them to see if they work on AOD's without
the Lentech valve bodies.
- For plain AOD's, for hi-torque, www.converter.com (Precision) and tci have
hardened input shafts, an AOD weakness. Trans disassembly is not required
to install them but you do have to remove the tran. Just pull the old shaft
out of the front of the trans and replace.
Many major internal mechanical parts interchange between all versions,
nearly all within AOD/E and 4R70W. This means you can get a good
used 4R70W trans (or internal parts) & use many of these improved individual heavier duty parts
(not the valve body or shafts) in an AOD case, such as clutches, wide ratio gear
sets, etc. AOD/E and 4R70W cases are the same. AOD/E's and 4R70W's also both
have an electrically controlled valve body. The cases for Windsor-fit trans have
a 2 bolt starter mounting, for mod motor they are 3 bolt and won't interchange,
but many internal parts will except for electric to manual valve body cases (all
will interchange between /E & 4R's).
SUMMARY OF GEAR CHANGES / APPLICATIONS
- Later '95 & up cases are stronger
(just AOD/E & 4R70W)
- Cases for 3.8 & 4.2 V6's and 5.0 & 5.8
V8's are all the same for the same model
- The electric control connectors on 4R70W's
changed between '97 &
'98. The ones on Mustangs have a better
shift pattern, & the Mustangs have
a better shifter.
- 1st gear - forward clutch applies upon
engagement, is locked while in gear 1st
thru 3rd gear, low 1 way clutch is locked
- 2nd gear - intermediate clutch applies & intermediate
1 way clutch locks; for manual 2nd gear,
OD band also applies.
- 3rd gear - direct clutch applies
- OD - OD band applies AND forward clutch
downshift to 3rd from OD - OD band releases
and forward clutch reapplies
MISCELLANEOUS PARTS AND TIPS
- Accumulators CONTROL (or modulate) the
increase in pressure (pressure rise) that
applies clutches (too rapid clutch application
induces too great of a shock load which
can cause part failures)
- For AOD/E's & pre-98 4R70W's, replace
the aluminum 1-2 accumulator with the molded
rubber over steel accumulator, stock Ford
accumulator # F7AZ-7F251-AA, cover F4AZ-7F247-A, & spring
F752-7F284-AA from 98 up. For hard shifts
at all throttle positions leave out the
original spring on the bottom of the piston.
Leave it in for firm shifts at normal throttle
but hard shifts at full throttle. The part
# on the cover faces down. It's not necessary
to remove the valve body to replace the
1-2 accumulator. It's held in by a snap
ring, front driver side of the valve body
and is accessible by just dropping the
pan. If the accumulator bore is rough,
smooth it with ScotchBrite, clean well
then lube & install the new accumulator.
Be careful removing the cover, it may be
under a lot of tension.
- The stock aluminum 2-3 accumulator also
needs improvement in all AOD's, AOD/E & 4R70W's
through '97, use Ford rubber molded #F7AZ-7H292-AA.
The 2- accumulator fits up under the valve
body. Leave out the stock return spring,
and bend the tabs out on the retaining
clamp SLIGHTLY with pliers to keep the
accumulator in the bore. ScotchBrite the
bore if rough; clean well, and lube with
ATF before installing.
- The '96 up dimpled pan F6AZ-7A194-A and
matching filter F6AZ-7A098-A are made to
prevent oil starvation(there is a dimple
in the bottom of the pan and the filter
pickup goes down into it, for cornering & acceleration)
Ford part #F8UZ-7A194-AA pan with drain
plug for AOD/E’s and 4R70W’s.
AOD’s have a different bolt pattern
on the pan. Most aftermarket trans shops
sell deep pans. The stock 4wd AOD pan is
deeper, and the 4wd filter has a pickup
tube on the bottom of the filter to pull
fluid from near the bottom of the pan.
- For better 3-2 shifts, enlarge the direct
clutch exhaust (in the valve body separator
plate and maybe the exhaust hole in the
direct drum?) CHECK with a good rebuilder
like Carr or Baumann or Level Ten about
- Do NOT do manual 4-2 downshifts in '98 & older
transmissions, the fluid exhaust from the
direct clutch is too slow. '99 & newer
valve bodies allow manual 4-2 downshifts
because they have better fluid exhaust
- With all versions of the Ford automatic
OD transmissions, there can be valve body
problems in used units. See Sonnax for
a listing of transmission problems and
possible cures using their products, and
especially for valve body repair.
See the last page (pg 17) of the tccoa article
for driveline &
drive shaft information such as drive shaft
harmonics, the effect of using deeper gears,
and for adding pressure lubrication to the
tail shaft output bushing for high speed use,
use with deeper gears, or high horsepower applications.
For an absolutely GREAT detailed set of instructions
with good pictures on things to watch for
and do when rebuilding a 4R70W type
trans, by all means check out this website!
OIL TEMPERATURES, COOLERS, & FLUIDS
INTERNAL REBUILD & HIGH PERFORMANCE
- A good oil cooler helps prevent oil
friction additive breakdown. A plate type
is the best (most efficient).
- The Long brand Low Pressure Drop (see
Baumann) is reportedly very good, also
the B&M plate type cooler. I got a
good plate type DeRale cooler at O’Reilly’s
for about $60 in mid-‘05. Install
the cooler in the line between the radiator
cooler and pan, downstream of the radiator.
This is a good point because it's where
the fluid is the hottest. Use oil resistant
hose (usually in the kit). The lines are
5/16"OD tubing, the fittings are 1/4" pipe.
- The return on an AOD/E and 4R70W is the
- The return on an AOD is the lower line.
- Stock plate type coolers in '98 up Mustang & '96
up T-Bird radiators are the best stock
but good for only about 300 hp.The ideal
maximum trans fluid temperature is 170°
F. The fluid life is cut in half for each
20 degrees over that. It's best to change
fluid each 20K for normal driving if you
use regular fluid, each 12k for hard driving
OR install a trans fluid temperature gauge
inline going to the radiator cooler & watch
- base change interval on max temps. If
the maximum temperatures seldom exceed
170F, you can go closer to 50k on changes
especially with synthetics like Mobil 1,
or Mercon V, which have more additives
and withstand heat better so can be run
- Do NOT use Type F in any OD transmission,
the internal gears will wear. However,
it’s OK for racing only as it enhances
clutch clamping friction.
- Type F is a very good high performance
fluid for non-OD Ford transmissions like
the C-4 & C-6.
- In AOD/E & 4R70W's, if the converter
clutch shudders during application, use
Mercon V or Mobil 1. They have more additives
so don't break down as quickly, and have
higher heat capacity.
Also add a good plate type cooler.
- For AOD/E & 4R70W converter shudder
the Mustang EEC transmission control calibration
is OK. Others need the calibration modified
by a Ford dealer, or use a good aftermarket
control box like Baumann's. Also see the
Sonnax website for other possible cures.
- The '98 up "mechanical diode" 1
way intermediate clutch is necessary for
high performance use in all models including
the AOD. It's included in the Ford retrofit
wide ratio kit F8AZ-7AO89-AA, but this
kit is very expensive, about $600. From
Ford, it includes the good wide ratio gear
set and a 4 plate intermediate clutch.
The mechanical diode will not fit a cast
reverse drum in '90 and earlier AODs. Several
vendors sell a mechanical diode kit which
does not include the wide ratio gear set
like the Ford kit, and so is quite a bit
cheaper. Baumann carries a retrofit kit
that will work with 90 and earlier units
that includes a stamped steel reverse drum,
a 2” OD band, the mechanical diode,
and necessary hardware, for about $350. www.transmissioncenter.com has
a kit without the tamped steel reverse
drum for under $150 but only fits 91 and
newer transmissions that already have the
stamped steel reverse drum. ALL of the
parts in the retrofit kit are already in
'98-up 4R70W's stock from the factory,
and can be retrofitted.
- VERY CAREFULLY check the ring grooves
in the pump stator support. They can get
worn from "debris" in the fluid,
such as friction material worn off of clutch
plates or (worse) from metal particles
from part failure in the trans or converter.
If ANY bad signs, especially on the edges,
replace with a new one, Ford part # F4AZ-7A108-A.
Use production sealing rings F4AZ-7D019-A
for the forward clutch, not Teflon (takes
too long to seal during warm up).
- For the reverse clutch seal rings use
Ford part # EOAZ-7D020-A.
- The 2 forward clutch seal ring grooves
on the stator support MUST NOT be gouged,
they MUST be smooth. See page 11 in the
referenced TCCOA article for more details
- If there is slip or shudder on take-off,
the forward clutch seal rings on the pump
stator are worn or leaking. If there is
ANYTHING other than friction material in
the fluid, install a new radiator (new
cooler) because the cooler is difficult
to properly flush out, and remaining debris
will prematurely wear those rings and grooves
and cause early failure. The radiator cooler
can be professionally flushed ONLY if it's
just friction material contamination. ('96
up T Birds and '98 up Mustangs have the
better plate type trans coolers in the
radiator). Some aftermarket shops also
carry a radiator cooler flushing kit (check
Baumann and Carr)
- Do NOT use a shift kit that puts blocker
rings into the 2-3 accumulator to firm
shifts, this causes damaging shock load
into internal gear train parts. Using more
than a maximum of 225 psi line pressure
in any forward gear distorts clutch cylinders
which causes pistons to stick, the transmission
slips, gets hot, etc.
- The Baumann AOD shift kit can also raise
WOT shift points up to 1100 rpm higher,
which is adjustable.
- Baumann also has a good kit for the AOD/E & 4R70W,
or see the TCCOA articles for modifying
the stock valve body and controls.
- Do NOT use a Kevlar OD band for regular
street use - they are so slick and hard
that they slip a little under WOT even
with a good shift kit & high line pressure,
causing heat buildup.
- For a 2" OD band like in some AOD/E's & in
4R70Ws, and with the Ford wide ratio kit
in AOD & AOD/E's, use the stock Ford
4R70W 2" band Ford part #F2TZ-7F196-A
for all but all-out race or very high power
and torque. If you can't use a 2" OD
band, a good alternative is a good aftermarket
heavy duty band like from Art Carr or others.
Do not use Kevlar lined bands for other
than occasional street use as they can
slip slightly (50 rpm difference), even
with high line pressure and bigger servos,
which creates heat buildup.
- The Pressure Regulator Valve for AOD/E
and 4R70W's are prone to wear and sticking.
There is a Sonnax replacement hard anodized
aluminum valve with other improvements
to reduce wear. Highly recommended to add
to any transmission with over 40k miles.
The valve body must be removed to install.
The Pressure Regulator, Boost and throttle
valves on AOD's have similar problems.
There is a Sonnax replacement hard anodized
aluminum valve with other improvements
to reduce wear. Highly recommended to add
to any transmission with over 40k miles.
The valve body must be removed to install.
The Bypass Clutch Control valve for AOD/E & 4R70W's
can lead to problems with converter lockup
clutch slip and shudder. Sonnax has a replacement,
as well as other worm valve body parts.
- Many AOD shifting problems can result
from worn or sticking valves in the valve
body. If you've had an internal mechanical
failure and metal particles have circulated
inside the transmission, suspect the valve
body if it doesn't shift after a rebuild,
even if it has been disassembled and cleaned.
New or rebuilt stock valves are available
from transmission shops. I bought a rebuilt
one for under $100 (Jan '05).
- If you have had internal mechanical failure
or significant wear of hard parts and have
metal particle contamination, it is absolutely
best to install a new radiator, or a good
used one with a transmission cooler that
you're absolutely sure hasn't been contaminated
with ANYTHING but normal friction material
wear particles (the gray sludge you see
in the bottom of the pan when you change
fluid). It's impossible to totally flush
metal particle contamination out of a remote
or radiator trans cooler. It's just as
important to install a new (clean) torque
converter or, if you have a high performance
aftermarket converter, to send it back
to the maker to have it cut apart and cleaned
out. They'll freshen up any worn parts
inside of it at the same time. I did this
for a stock diameter 2500 stall lockup
AOD converter for $150 plus shipping. Also
flush your cooler lines well. There are
commercial " flush kits available
for radiator coolers and lines, or you
can flush with solvent, blow out, and rinse
well with clean fluid before you hook them
The wide ratio gear set when installed in an
AOD increases the WOT shift points. The typical
AOD mustang shifts 1-2 at about 4900 rpm, with
the wide ratio this increases to about 5680
rpm. As this may be too high depending on your
engine, this can be reduced by installing a
lower rpm governor on the tail shaft. E2AZ-7C063-B
is the "medium" speed governor, E8AZ-7C063-A
the "low speed". The typical AOD
mustang 2-3 shifts increase from about 4500
to 4750 rpm with the wide ratio kit. The Baumann
AOD shift kit can then be used to further modify
WOT shift rpm within an 1100 rpm range. Also,
Lentech addresses this in their valve bodies.
I highly recommend getting a good rebuild video with a manual from i.e. Summit
or Jegs. I had not rebuilt an AOD before (had done other types) and had an ATSG
manual which was very confusing to someone who was not familiar with an AOD.
There are many different sizes of bushings. I put the new ones in a cold freezer
awhile to shrink them a little. I used large sockets turned backwards on an extension
as bushing drivers instead of buying a big set of drivers. I made a clutch pack
compressor (to compress the clutch pack to get the snap ring out or back in)
out of a piece of threaded rod with a strap of metal on each end that compressed
using a nut on each end. Rebuilding is not difficult except for 2 major things:
- The output shaft bushing in the case installs from the inside, which takes
a very long driver handle. I made a driver using a long slide hammer handle
to get enough reach inside the case.
- The lip seals in the clutch drums are very difficult to install without
the special installers. There is a lip inside the drum that the lip seal
on the piston, which points inward, has to go inside of. I used strips of
aluminum cut out of beverage cans, with the cut edges smoothed, as seal installers.
I had to work very slowly and carefully to get the lip seals inside of the
lip in the drum without damaging them. A good option might be to take the
trans out, disassemble it and clean it, then take everything to a good reputable
trans shop for reassembly. Seal protector sets are available from several
aftermarket vendors starting from $70; check the links at the end of this
BEST HIGH PERFORMANCE STOCK PARTS & INTERCHANGE
- For the BEST heavy duty parts, or entire transmission, the 5.4 truck 4R70W
is the strongest.
- For up to 450 hp, most V8 and 4.2 V6 model trans, depending on year,
have perfectly good parts. ALL those parts can be swapped into any AOD/E
case or any other 4RW70 case. This includes all 3.8 & 4.2 V6 4R70W's
and also V6 AOD/E's, which all bolt to 5.0 or 5.8 Windsor's. Many of those
HD parts will fit in an AOD (I.e. clutch packs, wide ratio gear set, mechanical
- The stock '98-up 4.2 V6 4R70W (light truck only) has the same number
of clutch plates as the V8 models and bolts to a 5.0 or 5.8. Just don’t
forget that the manual shaft & lever assembly has to be switched to a
car shaft & lever if installed in a car. Takes removal of the pan and
a roll pin. Car levers point down, truck levers point up.
- Other than for use with very high power or serious racing, any '97-up
3.8V6 or '97 4.2 V6 4R70W trans just needs 1 stock clutch & steel set
added to the direct clutch pack (a relatively easy job) to equal a stock
V8 4R70W and they bolt up to Windsor V8's. Stock with a good shift kit
they are as strong as any stock V8 AOD, or you can take most of the internal
parts out of any 4R70W and put in a plain AOD - such as clutch packs (except
the forward clutch / reaction shaft assembly) and the mechanical diode
and sun gear assembly, which are much more durable from especially the
- AOD's have partial lockup in 3rd, full lockup in 4th, which can't be changed
unless you eliminate lockup altogether. That reduces full power transfer
in OD and hurts mileage EXCEPT www.lentechautomatics.com valve bodies change
operation in an AOD and have no lockup in 3rd. They also have electric control
of lockup in OD in their valve body with a manual lockup switch control by
the driver. Using heavier especially secondary clutch packs is good for using
a Lentech valve body - they use that clutch for 3rd instead of the direct
clutch which is inherently weak, especially in the plain AOD.
- Control chip: If going to an aftermarket chip (or complete control box
like Baumann's) for an AOD/E or 4R70W, make sure it provides full converter
lockup at WOT and more pressure for the 2-3 shift.
- Output shaft, (for AOD /E & 4R70W only): ONLY use the 4R70W shaft.
It's made of stronger material. Do not use a Crown Vic or police output
shaft. For all trans models, use a shaft with a 7 tooth speedo drive gear.
That's OK up to 3.73 gears. Any deeper requires a special speedo driven
- Many cars with 2.73 gears have an 8 tooth speedo drive gear which doesn't
work with gears lower than 3.27. The very best (hi torque or blown) is a
98 and newer output shaft. For under 450 hp, a '95 up shaft is OK. These
all have larger lube feed holes, but check closely to make sure the ring
grooves are good.
- The smaller rings on an output shaft should be 1 piece Teflon instead of
split like OEM because they seal better. The aftermarket vendors listed have
install kits for the solid Teflon sealing rings. The larger rings should
be OEM, NOT Teflon rings which wear the inside of the case bore too quickly.
The 7 tooth output shaft to use for AOD/E or 4R70W is Ford Part # F4SZ-7060A
if you need to buy one.
- For an AOD, the ONLY output shaft to use for performance is the '93 Mark
VIII, it's a 4R70W shaft that is hardened for use with the wide ratio gear
set but is the only hardened (4R70W) output shaft that still has the necessary
governor hole, but you have to add the governor. You could also get your
AOD output shaft hardened.
The AOD & AOD/E gear sets can NOT handle frequent high torque OR sustained
high speed as well as 4R70W gearsets. They have aluminum bushings. Pre-96 4R70W
gear sets still have some aluminum bushings. OK gear sets for up to 450 hp are
96 & newer 4R70W. They have bronze instead of aluminum bushings. 4R70W gear
sets also have caged needle bearings. The strongest gear set is in the 5.4 truck
4R70W trans. They have stronger pinions & gears. See the TCCOA
article, page 7, for a complete Ford parts # list for the best 4R70W
gear set. Baumann has a rear gear train lube retrofit kit for pre-'88
AOD's, but those gear train parts are expensive if worn out, which
they are likely to do with inadequate rear gear train lube, so it
is risky to buy a pre '88 AOD.
- Direct clutch drum: AOD/E's & 4R70W's
have stamped steel direct drums that take
different clutch plates and hold more clutch
plates than the cast AOD direct drum through
'89 and partial '90, and can be swapped
in place of the cast drum. The cast AOD
drum can hold 6 high performance plates
, and you can get thinner Alto “Red&
8221; high performance frictions which
is then OK up to about mid 300's horsepower.
Some rebuilders have reported that the
thin Kolene treated high perf steels can
warp from excessive heat.
- Stock Mustang V8 AOD direct cast drums
usually had 5 plates, Lincoln LSC's usually
had 6 BUT check the drum input splines
closely in a cast drum. They can wear and
allow the shaft to slide to the rear in
the spline and cover the lube hole in the
end of the output shaft which blocks lube
to the planetary bushings.
See the Baumann site for a detailed explanation
and a picture of the splines in the cast drum.
When I got the Art Carr premium heavy duty
kit for my '89 AOD, I was able to specify which
type of direct clutch plates as I switched
to the stamped steel direct drum and added
extra plates. The pre-'97 stamped drums will
hold 7 thinner high performance frictions like
in the Alto kit.
- Stock AOD/E & 4R70W 4.2 V6 and all
V8 transmissions have 6 frictions and 5
steels in the direct drum. The best stock
Ford type of direct clutch plates &
frictions to get are '98 and newer. The
steels are thicker and withstand more heat.
The frictions have better facing material
that lasts much longer. Frictions are F8AZ-7B164-BA,
steels are F6AZ-7B442-AA, and the pressure
plate in the outside end of the drum is
- A stock 6 friction direct drum is good
up to about 500 horsepower, the '98 &
up frictions & steels are more durable.
To use 7 frictions and 8 of the thicker
steels (use a steel on the outside end
instead of the pressure plate) although
that may make for somewhat uneven and therefore
reduced clamping pressure due to flex takes
a '97 & up drum F6AZ-7F283-AA. It has
more room inside as the snap ring groove
is farther out. Set clearance with selective
snap ring thicknesses. Use .010"
clearance per plate in the direct clutch.
Stay slightly on the high side especially
for street use if you can't get it exact.
See the big TCCOA article for a complete Ford
parts # list including part #'s for the different
thickness snap rings.
SUMMARY OF BEST PARTS & YEARS STARTED
IN STOCK PRODUCTION
- A bad direct clutch or bad intermediate
1 way clutch causes no 3rd or 4th gear.
- Forward clutch: AODE's & 4R70W's
have a 5 plate forward clutch stock . That's
OK as it clamps only for 1st gear engagement,
then it only has to hold the torque while
applied. It does not apply during any upshift.
The forward clutch has a wave plate (spring)
instead of an accumulator. All thru '95
have the same wave plate.
- '96 up, except 5.4 trucks, have a stronger
wave plate which are OK up to near 450
hp, F6AZ-7EO85-A, .072" thick. For
over 450 horsepower, use a 5.4 truck wave
plate XL3Z-7E085-A. It's .081" thick
and stiffer. It causes firmer engagements
into 1st and firmer OD to 3rd downshifts,
and is recommended only for very high torque
or serious racing. Some builders delete
the wave plate and add another steel back
to back with an existing steel to make
up the thickness. I did this and the engagement
with a 2500 stall converter is noticeably
firm but not at all "
objectionable although the OD to 3rd downshift
is quite firm even on normal slowing-down
downshifts. The object with a stiffer wave
plate or deleting it altogether "
is to hold more torque while accelerating
thru the gears or to avoid slip "
when full throttle downshifting into 3rd
- The standard '96 up plate has 3 waves,
the 5.4 plate has 4 waves. With a '96 up
forward clutch cylinder you can use 6 or
7 plates for extreme power capacity.
- Pre-'90 and some '90 AOD's have a cast
forward clutch cylinder, they need a '90
or later stamped steel forward clutch cylinder
for the 4R70W clutch discs. A reverse cylinder
assembly, includes the mechanical diode
(intermediate 1 way clutch), is needed
for higher power. It's Ford part # F8AZ-7AO89-AA,
and is stock in '98 & newer.
- Intermediate clutch: A 4 plate intermediate
clutch is needed for any high performance.
All AODs, AOD/E's & 3.8 V6 non-blown
4R70W's through '98 have 3 plates. All
other 4R70W's have 4. To go to the 4 plate
clutch, you need to change to pressure
plate F7AZ-7B066-AA, add 1 friction F752-7B164-CA
(good for up to 450 horsepower) and 1 steel
XL32-7B442-BA. (See chapter 10 of the TCCOA
article for more details.) ONLY use the
current non-grooved frictions IF used with
an aggressive accumulator for over 450
hp or there won't be enough pressure to
apply the clutch fully & it will slip.
- Symptoms of intermediate 1-way clutch
problems on pre-'98 trans are no 1-2 shift,
or no 3rd & 4th gears, or late 1-2
shifts that bang. The cure is the '98-up
mechanical diode intermediate 1 way clutch
- Stub Shaft: Only used on AOD/E & 4R70W,
this connects the forward clutch cylinder
to the direct clutch cylinder. Use only
a '98 & up stub shaft, Ford part #
F8AZ-7F351-AA. It’s stronger material.
(See page 10 in the TCCOA article for details.
- Overdrive servo: Use the "A" servo,
part # F75Z-7H188-AA and spring F87Z-7F201
AA for up to 425 hp. For over 425 horsepower
use the F2VY-7F201-A spring, or A or larger
A+ servos are available from the aftermarket
but still use the high performance Ford
spring for higher horsepower.
- 1-2 accumulator - Use the Ford molded
rubber over steel part # F7AZ-7F251-AA
with cover F4AZ-7F247-A, & spring F752-7F284-AA
from 98 up, See the info earlier in this
write-up for more details. AOD/E's and
4R70W's only, AOD's do not have a 1-2 accumulator.
- 2-3 accumulator: Use the Ford molded
rubber over steel part # F7AZ-7H292-AA,
which is stock on '98 & newer. Be sure
to blow the small air bleed hole near top
of the OD servo bore clean. This retrofits
to all models, and is available also through
the after market links listed in this article.
- For high speed road use, or with gears
deeper than 3.73, the longevity of the
output shaft bushing at the end of the
tail shaft housing benefits from pressure
lubrication. (See page 12 of the TCCOA
article for details and pictures.)
BEST STOCK 4R70W THAT WILL BOLT TO WINDSOR
- Case (AOD/E & 4R70W): '95 & up
- AOD cases are all the same.
- Shift accumulators (1-2 & 2-3): '98 & up.
Easy to add the 1-2 to older AOD/E & 4R70W,
just drop the pan. To add the 2-3, you
also need to drop the valve body. Also
retrofit this to AOD's.
- Mechanical diode (intermediate 1 way
clutch): '98 & up MAJOR EXPENSE TO
BUY SEPARATELY, but "MUST HAVE" for
HP (also has the 2" wide od band stock).
Is part of the reverse drum assembly. '93
thru '97 4R70W’s have an improved
14 roller intermediate 1 way clutch which
is better than the earlier 7 roller units,
but the mechanical diode is still way better
and important for high performance use.
- Pan & pickup: Dimpled pan and extended
pickup (prevents starvation during acceleration & cornering):
96 & up. Fits AOD/E's and 4R70W's only,
not AOD's. 4 wheel drive AOD pans are deeper,
but you then must use the 4wd filter as
it has a pickup extension. Deeper aftermarket
pans are also available for all types..
- Output shafts (for AOD/E & 4R70W)
: '95 & up good to 450 hp, '98 & up
for blown / extreme torque & power.
- For AOD, use the '93 Mark VIII, you have
to add the governor.
- Gear sets: '96 & up good to 450 horsepower.
Very best is the 5.4 truck gear set for
blown / extreme torque & power.
- Direct clutch pack: '98 & up stock
6 plate (has thicker steels & better
material on the frictions).
- Direct clutch drum: '97 & up has
room for an additional clutch friction.
Over $100 to buy & retrofit, can also
be used in the AOD.
- Forward clutch wave plate: '96 & up
good to 450 horsepower. Use the 5.4 truck
plate for extreme torque / power, causes
- Intermediate clutch (need 4 plate): blown
3.8's and all '99 up, however 4th plate
can be easily added to 3 plate clutch.
You need the thinner 99-up pressure plate
marked “4 plate” to do this.
- Stub shaft: (AOD/E & 4R70W only):
'98 & up is the strongest.
- Forward clutch: (pre-90 AODs with cast
drums only have 4 frictions). '96-up with
stamped steel drum has 5 frictions stock
good to 450 hp but has room for 6 frictions
for up to 550 hp or can be modified to
hold 7 for extreme power. Retrofits to
all older /E & 4R older models. 90-95
stamped steel drum holds the stock 5 frictions.
'90 – '93 AOD forward clutch drum
is stamped steel and is the only one that
will retrofit to older AODs with cast drum
because of the difference in the reaction
shaft that is part of the assembly.
- The BEST 4R70W trans that will bolt to
a Windsor V8 is a '99
& newer 4.2 V6. It has all the best
parts and the same number of clutches
as the V8 mod motor transmissions. This
trans has: best case, best accumulators,
mechanical diode 1 way intermediate clutch,
dimpled pan & extended pickup, 450hp
capable gear set, best direct clutch drum,
best direct clutch plates, best forward
clutch wave plate good to 450 hp, best
intermediate clutch (4 plate), best stub
shaft). Just remember that for a car install,
you must switch the manual lever to one
from a car.
- NEXT BEST 4R70W TRANS THAT BOLTS TO 5.0 & 5.8
is '98 3.8 V6 or 4.2 V6. The difference
from '99-up 4.2 V6 which will bolt to 5.0 & 5.8
is 1 less intermediate clutch plate - easy
to add - and the valve body does not have
good direct clutch fluid exhaust for 4-2
- ALL prior to '98 do NOT have the expensive
mechanical diode 1-way clutch.
See the TCCOA article for stock shift control
modifications, but must use matching stock
computer. Maybe best & easier to use an
aftermarket control. See the TCCOA article
for watch-outs on aftermarket controllers.
See www.alternativeauto.com's "water box
archives" for a write up on the excellent
Baumann electronic control. Also see Phils
for a very detailed swap write
up. Although it’s into an older classic
Mustang, there are lots of good tips especially
including detailed info on installing the Baumann
at LaSota Racing is a very
comprehensive article on installing a 4R into
an older ('95) vehicle. It includes valve body
and control information. The '95 vehicles still
use EEC-IV but were equipped with an AOD/E,
which has a similar trans control wiring setup
to the 4R units. The article goes into detail
on valve body mods (per the Jerry vb mods as
detailed on www.tccoa.com) and the ecu control
of the trans. There reportedly wasn’t
room in the EEC-IV ECU for OD lockout, so Ford
used a stand-alone module which isn’t
made any more but should be available in junkyards.
The info and Ford part # is in the article.
It might even be possible just to use a toggle
switch to lockout OD.
Also, Tweecer tuners can reprogram those '94/'95
ECU’s for not only the
engine but also some items for the transmission, apparently somewhat
the same as the Baumannator stand alone control, so dyno tuners
might also be able to perform transmission tuning with this setup
although the results can only be tested while actually driving the
I researched how to use the '94/'95 ECU in an older EEC-IV vehicle that did not
originally have an electronic trans. The options would be either to wire in the
'94/'95 ECU just to run the trans, or to completely replace the older ECU with
the '94/'95 unit. There are obviously some differences in wiring for the '94/'95
After some study, there are apparently quite a number of differences both in
the engine wiring and in the various devices, such as sensors, solenoids, relays,
etc. Also, as the '94/'95 ECU is reportedly considerably trickier to tune, it
may be best not to go through the work to replace an earlier ECU with it. It
seems to be much easier just to wire it in tandem or parallel with the existing
pre-'94 ECU just to run the transmission. The inputs obviously would be from
the transmission harness, plus power, ground, and probably an rpm signal from
the ignition, and the voltage signal from the TPS. However, I have been informed
that the Tweecer cannot modify many of the parameters of the '94/'95 ECU where
the transmission is concerned, so anything beyond very basic tuning is seemingly
beyond the scope of the Tweecer as well as other similar tuning devices.
So, thus far, it seems it comes back to the Baumann control as being the most
practical solution to controlling a retrofit electronic transmission, especially
as it is in the same cost range as apparently less capable devices for tuning
the transmission, such as the Tweecer. Not to mention that those tuning devices
are very learning intensive, and that most people might be better off with a
good engine dyno tune than to try to tune their own ECU especially for a modified
This is the last step in my installation of an '00 4.2 4R in my '89 Mark VII,
and I will update this if I learn more about this part of it. (I
purchased the trans at a good price from Jim Hardin at IndianaCoreINC@aol.com.