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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 - 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 (changing to 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 for decent discounts on genuine ford parts.
Check and Ford Racing for information on high performance Ford parts and part numbers.



For an excellent schematic and parts breakdown and listing by year and type, see Transtar Industries. (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 or Art Carr or Sonnax for the cure, including improved accumulators.
  • 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, 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,, (Precision), also and Pro-Torque. I'm sure there are others. Also check 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, (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).
  • 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 transmission.
  • 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 releases
  • downshift to 3rd from OD - OD band releases and forward clutch reapplies
  • 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 this.
  • 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 ports.
  • 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! tech/4r70w_rebuild.html


  • 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 upper line.
  • 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 longer.
  • 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. 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 and information.
  • 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 back up.
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.

Rebuild Notes

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 article.

  • 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 diode).
  • 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 '98-up 4R70W's.
  • 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 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 gear (aftermarket).
  • 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 F7AZ-7B-66-AB.
  • 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.
  • 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 from OD.
  • 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 assembly.
  • 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.)
  • Case (AOD/E & 4R70W): '95 & up is stronger.
  • 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 hard shifts.
  • 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 manual shifts.
  • 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's "water box archives" for a write up on the excellent Baumann electronic control. Also see Phils 4R70W Swap 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 TCS control.

UPDATE: 4R70W Retrofit Swap 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 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 vehicle.

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 ECU.

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 engine.

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

- macx

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