Drive shaft upgrade choices ? 90 Mark VII

[marked for life]

I need to know how much power that the stock drive shaft can handle ? Concerned about that rear double universal joint yoke and the single one back there also. Which universal joints do I install ? I want the best money can buy. Brand and part numbers. I want to replace the front yoke with the best part available. I do not want to go with a straight shaft because of possible vibration ??? The tranny has had max upgrades and the rear has an eaton posi and 31 spline moser axles with a rear end girdle, I will have close to 600 lb/ft rwtq to propel my 4300 lb LSC. I am going to have a brand new drive shaft built.

[Bluegrass]

Hang on.
As soon as I can find the contact, I will PM you with it .
The guy runs a mid to hi 10 second Mark 7 with a 331/KB blower at 15 psi.
I know he has upgraded his whole drive line including drive-shaft/joints and all.
I'm sure he will be happy to tell you what you need to know.
Tell him I referred you to him.
**************
A pm to start with, is at the upper right of your page.

[pro-five-oh]

Definitely make it aluminum to rev harder and lighten the car. Not sure on the U-joints, but it sounds like you'll get the info soon enough.

[v8_dave]

I bet picking up a Metal Matrix driveshaft (much better than even alum) from a junkyard '99-00 CVPI and having custom yokes welded maybe a feasible lower cost option to look into.

[marked for life]

Whats a CVPI ?

[cason1]

Crown
Vic
Police
Interceptor

The newer cop cars are referred to as CVPI's.

[JoshMcMadMac]

Whats a CVPI ?

Crown Victoria Police Interceptor.

One options is to get an aluminum shaft off of an Astro or Crown Vic, then have it cut to length.

[cason1]

Crown Victoria Police Interceptor.

One options is to get an aluminum shaft off of an Astro or Crown Vic, then have it cut to length.

Wow great minds think alike. Is it the Astro or the Aerostar to get one off of?

[marked for life]

What about that cv type joint on the rear of my driveshaft ? I heard the aftermarket extra long straight driveshaft vibrates on a Mark VII ,thats why ford engineers installed that yoke ???

[SilverFox]

not 100% on this, but the double yolk was installed to cure the drivline angle after the rear spring blow out....meaning, if the suspension is dead, the drivline angles won't be severe enough to ruin the joints and yolks while it is driving around on the ground.

Blue would probably know :)

[mark007]

not 100% on this, but the double yolk was installed to cure the drivline angle after the rear spring blow out....meaning, if the suspension is dead, the drivline angles won't be severe enough to ruin the joints and yolks while it is driving around on the ground.

Blue would probably know :)

i believe you are correct. but it wont really matter on lowered marks. also arent there pinion type snubbers on the axle or on top of the pumkin to keep it from bottoming out all the way.

[1989LSC]

It is for vibration. The way my dad explained it to me was that it would cancel out vibrations caused by the production tolerances in the driveline. My dad actually was a suspension engineer on the mark 7 and 8 among other things.

[re-Markable LSC]

not 100% on this, but the double yolk was installed to cure the drivline angle after the rear spring blow out....meaning, if the suspension is dead, the drivline angles won't be severe enough to ruin the joints and yolks while it is driving around on the ground.

Blue would probably know :)


Rubbish...Myth. What 1989 LSC said.

[marked for life]

Does anybody have the straight driveshaft in their car now that can prove or disprove this theory on these two opinions? Any input ? Right now my car rides like it's on glass, I am going to call Denny's driveshaft and see what their opinion is. Also I want to say hats off to Silverfox for one brutal transmission, this thing shifts like an Indy car; No bull... Also Mark 007 how about an update on that project of yours.. It's been to long. How about a update from you to Bluegrass.

[Bluegrass]

My motor is almost ready to go but for a few details, like the headers.
Still have to pull the original motor out.
My blower and setup is just a puppy compaired to what you have but is all I want.
What does 'glass' mean?
Handling, traction?
My car has the big Mustang anti roll bar and two bars in the rear.
Awhile ago I softened the front links to reduce some of the road transmitted hashness, otherwise it is a flat handler.
I also have the air springs setting in one inch spacers at the bottoms to reduce the amount of air needed to attain stock trim heights.
Tying the car down like that is not aways good for off line traction but is nice on twisting roadways.

I would say that the rear cardan joint is more of a problem when the car rises off the axle than when too low.
Found that out one day by letting the rear hang and running the driveline up.
I thought the rear was going to come out from under the car till I realized the cardan joint was running at extreme angle with no pressure on the rear end to keep it from moving..

[marked for life]

I sent you an email with my number. smooth like glass

[Bluegrass]

Roger that.
I got back.

Was copying music discs off air for awhile, till I got back and saw the mail.;)

[JoshMcMadMac]

I have an aluminum driveshaft with my manual tranny, and it works just fine. A lot of guys run the one-piece aluminum driveshafts, and I am not aware of any complaints.

[NYC LS8]

The driveshaft that Josh has was mine at one time. Never had any problem with it.

[Bluegrass]

He has some very well based concerns due to the heavy duty power he will be putting thru the drive train that is much greater than what we are doing.
Better to try and address them before tearing up the car if something should happen but even then it's no guarantee.

[mark007]

Does anybody have the straight driveshaft in their car now that can prove or disprove this theory on these two opinions? Any input ? Right now my car rides like it's on glass, I am going to call Denny's driveshaft and see what their opinion is. Also I want to say hats off to Silverfox for one brutal transmission, this thing shifts like an Indy car; No bull... Also Mark 007 how about an update on that project of yours.. It's been to long. How about a update from you to Bluegrass.

not too much to tell right now. she's kinda on the backburner right now. should be back in full gear by the middle of next month. hoping to have it ready for sshs7. and that'll probably be without the paint and interior mods not done.

[Bluegrass]

I done some internet searching for 'forged' yoke hardware and see there are a lot of sources of these parts as well as custom driveshafts built for race cars.

[Britanski]

Good thread!
...
One thing I've noted from the Mark VII's is the smaller U-Joints. Unlike the thicker ones used on Mustangs. I had my custom driveshaft built with the thicker units.

But because of the torque my new motor will be making (400+ ft lbs.), I'd like to have some proven info on this driveshaft subject.
I've certainly heard about Aluminum driveshafts and the Aerostar Aluminum driveshaft mod. But is it really nescessary for a street car? Or is it just more performance parts hype?

I kind of liken this to some transmission facts...you'll hear many people talk about a stock T-5 able to take all kinds of HP and abuse. (AOD's much less)
Someone made a great point about that...
"Hey, most any tranny can take all kinds of HP because the wheels will just spin. The real trouble comes when tires grip! Then the tranny is put to the test!" :hyper:
Basically, that means a set of wide Slicks. I have no plans for that kind of tire. Mine's just a street machine with near factory-sized tires.

I think there are a lot of people who beef up their driveshaft that may not need to do so, and waste money and effort.

Please share any real experiences...

[SilverFox]

I don't have a alum drivline, but I KNOW from expeirence ANYTHING turning high rpm that can be lightened makes a big differance in HP loss. I am willing to bet an alum drivline is almost SEAT OF THE PANTS increase in acceleration.

[mark007]

Good thread!
...
One thing I've noted from the Mark VII's is the smaller U-Joints. Unlike the thicker ones used on Mustangs. I had my custom driveshaft built with the thicker units....

I too went with the thicker units. and got rid of the double cardan joint. cars lowered, and if the suspension happens to over inflate or lays down on me ... well then it happens and it'll be flatbeded home. but i seriously douybt that will happen.

But because of the torque my new motor will be making (400+ ft lbs.), I'd like to have some proven info on this driveshaft subject.
I've certainly heard about Aluminum driveshafts and the Aerostar Aluminum driveshaft mod. But is it really nescessary for a street car? Or is it just more performance parts hype? ...

i did mine preparation of a ungodly amount of tq i'll be throwin' to the rear wheels. if it all works out the way i plan. the cvpi d/s are nice and thick and will do the trick as will the aerostar ones, but for the average mark doing this that will be making 400 and under i would say that the aluminum is the way to go. i say that because at our power to weight transfer thats alot of abuse coming down the driveline. now for a car pushing over 500 tq and more with a aluminum d/s at full weight how long will said d/s last. could last awhile or could twist on the first hit. thats why i had a steel one made for my car. if you look at like this take a coke can and twist it. what happens it twist. now find a steel pipe about the same height and width of the coke cake, twist it if you can. end result steel holds up better. so aluminum too me is all hype. except that you get the weight benefit. and to be honest when i did mine the oe d/s weighed in at 31-32lbs iirc. and when had mine done it weighed in at 26lbs. i think the aluminum ones i have seen done were the same weight or maybe a lb or two lighter than that. and whats a lb or two gonna really matter in a full weight car.

I kind of liken this to some transmission facts...you'll hear many people talk about a stock T-5 able to take all kinds of HP and abuse. (AOD's much less)
Someone made a great point about that...
"Hey, most any tranny can take all kinds of HP because the wheels will just spin. The real trouble comes when tires grip! Then the tranny is put to the test!" :hyper:
Basically, that means a set of wide Slicks. I have no plans for that kind of tire. Mine's just a street machine with near factory-sized tires....

i really cant say for sure on this one, but i know on the stock motor with the 1.5 kb that was on there and a pulley swap that the stock tires would go up in smoke at 3/4 to full throttle. i put on the drag radials and she dead hooked everytime. could tell ya what boost was at but it was a difference from the larger(3 1/4)pulley. oh and that was before the fully worked over tranny went in. after the tranny went in i couldnt say anything, but just grin from ear to ear. and for a few days before the headgasket blew out. 5-speed guys were catching hell. especially a white 90 lx with a red hatch, he had heads and intake work done. if he still has that car its gonna be the first one i go lookin' for.

I think there are a lot of people who beef up their driveshaft that may not need to do so, and waste money and effort.

Please share any real experiences...

this statment holds some truth but to each his own. in some cases that money could go towards other maintenace upgrades, or put away until something else comes up. but in m case i sorta already knew where i was going to go with the car when i go it. so i was basically getting ahead of the game, but i might have been better to do later and i could have done real world dyno results of before and after upgrades. but oh well.

[Britanski]

Well... if I read your run-on sentences correctly ;) .. . I'm not going to waste any money for an aluminum d/s.

Thanks for the info and experiences.

Yeah, I ditched the double joint as well. I think my old '75 Mark had that too.

[Bluegrass]

For forged pinion yoke and transmission yokes, look at Jegs's page 176-n catalog.
Page 174 -n for Moser parts. 175-n for U loint girdles etc.

[mrizzolo]

I know this post is a little old but I build drive shafts for a living and i just built an aluminum shaft for my car. I have the aod trans and i eliminated the rear "H" yoke on the new shaft. My car now has a slight vibration in first gear under hard acceleration. I know the shaft is perfectly straight and balanced. Which leads me to believe the yoke is primely used to reduce vibration while accelerating.

Our stock shafts weigh around 25 lbs. My aluminum shaft is 12-13 lbs . With this reduction you can clearly feel a difference in power. Because the rotational mass is less you can expect up to a 10 hp gain.

As for picking up an old aluminum shaft. It's doable but not the best idea. Factory shafts and fairly thin any where from .065 thousands to .083 thousands thick. For steel this is ok. With aluminum it is better to use tube that is .125 thousands thick. And most of the time it's more work to use an old shaft and the results aren't great.

I'm going to try and up load some pictures with in the next day or two.

[Bluegrass]

The stock 'Cardan' joint adds to the distance the joint can run out of alignment before joint bind takes place asuming the drive shaft has no balance or bowing faults..
One tends to find these joints on vehichles that could have a lot of body height change ie the Lincolns and even on a 80s Bronco II with very short drive shaft, two greatly difference vehichles in weight, size and wheel base, spring rates etc..
The rear winds up to far and the body changes trim height to much for a single joint unless everything is perfect, restricted and /or tied down on both these examples.
On a Lincoln, brake stalling the car usually raises the rear body height due to axle rotation effects on the 4 link suspension arm geometry. Acceleration power tends to keep the rear wound up especially if starting from a brake stall position.
If steps are taken to restrict this, preload the upper arms in the oppisite direction etc, a single rear drive shaft joint is more apt to be usable without a problem and gets out of control arm bind at the same time.

While a performance gain may be felt from a lighter weight shaft, it is not HP you feel since there is no parasitic loss due to friction or a drag moments; but is a rate of acceleration difference effect just like a lighter motor crank rotating assembly over a heavier one or taking weight off the car, light weight wheels, same motor/trans/rear in a lighter car. etc..
I only bring this point up to be technically correct about the effects of a difference in weight that dosn't 'directly' involve frictional losses.

[mrizzolo]

http://i130.photobucket.com/albums/p257/rizzolo55/09-29-07_1021.jpg
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http://i130.photobucket.com/albums/p257/rizzolo55/09-29-07_1135.jpg

[SilverFox]

Nice!

[marked for life]

Great insight, now this 80's bronco's II Cardan joint is what size, big universal joint or small ??? And also what exact year do I look for , I was pretty sure there might be some vibration issues with that shaft, what are you planning to do mrizzolo? If the 80's is a large cardan I think this might be the answer to my driveshaft issues.

[mrizzolo]

the bronco shafts i have worked on use the same series joint as the marks which is a 1310 size. any good drive shaft shop can build you a larger shaft with a bigger cardan joint and u-joints. just a matter of paying for the parts.

in all honestly building a drive shaft from scratch is the way to go and isn't that expensive. but thats a whole new topic.

as for my vibration.. i just installed the shaft yesterday. haven't really had the time to figure things out yet.. but the vibration itself isn't much at all. It only shakes in first gear under full throttle around 2500 to 3500 rpm when the engine torque is at its greatest. and it isn't a rattle the screws loose kind of shake just a little something you feel though the car. under normal driving conditions it doesn't shake at all and is amazingly smooth when cruising on the highway.

[marked for life]

By the way thank you for the photo's and your input; you say you can buy the cardan joint, ( great news). I want to buy the one for the large universal joints, where can I get this part and is the 1350 the largest you can go with or am I wrong here, also that front universal yoke has a vibration ring, do you think this could be your problem and I wonder if I could buy a front yoke (1350) with one of these rings. For testing purposes with your vibration problem you could use the universal joint for your stock front yoke for the small size that it is and has bigger universal caps and is wider for the 1350 yoke that your using, I think they call it a stepped universal joint. Is the spicer universal joint's the best out there or is there something even stronger? Great info by the way...

[marked for life]

Is that cardan steel or aluminum?

[Bluegrass]

We used a front bolt-on joint for 500 hp sprint car direct drive use but I would have to check what source and grade was used.
The joint was a flat flange to splined yoke, to splined solid shaft assembly bolted directly to the crank in an open wheel sprinter with no transmission.
The rear input was a splined collar connecting the shaft to the pinion drive.
At the motor we has a CNC machined custom motor bell housing that uses a large hollow ball mount to keep alignment and enclosed protection by a full outer housing back to the rear case. This provided a pivet point for the rear and one locating point along with outer radius rods to set for handling changes.
Never had a relibality or vibration problem with the setup.

Back in the early spring, I replaced the cross joint and cups in my Cardan rear joint. It's a bit of a hassle but can be done as long as you have a well mounted vise and tools to work with.
It's easy to get into trouble if you don't work with precision as once you over set the cups too tight and cause joint bind, you have to start all over again with new parts if they become damaged trying to corrrect or take apart again.
There is not much room for error. Only set the cups in just enough to get the lock rings in place even is you have to tap them in place with a small drift pin punch.

[mrizzolo]

If i find some time i can check my books tomorrow to see if the parts are available and what they offer. If you have a good drive shaft shop in your area you can talk to them about building a custom shaft for your needs. Our stock tubes are only 3.00 x .065. If you plan on using a 1350 series you would obviously want to jump up to 3.50 x .083. Anything larger is uncalled for.

You are correct the transmission slip yoke does have a damper ring on it. However this is not needed if the drive shaft is built properly. Because drive shafts are mass produced at the factory for new cars this is fords way of covering up any imperfections that might arise.

The aluminum shaft that i built is actually still only a 1310 series. I tired using the original slip but the ears on the new weld yokes are to tall and would not clear the damper ring. My engine is still stock and i don't plan on pushing to much more power b/c the car is a daily driver. However (and some of you may disagree with me) the aluminum shafts may be lighter but are much stronger than the steel shafts if they are built correctly. I have direct communication with spicer and this is there thoughts also. We built an aluminum shaft for a 900 hp stang and he blew out his rear end before breaking the shaft. If any of you are familiar with JDM engineering we build all their drive shafts that they sell and run in their cars. The blue stang in this video is running one of our aluminum shafts ( www.teamjdm.com/videos.php?id=2 ) hundreds of runs on the car and no problems to report.

As for u-jonits or any drive shaft parts... you can either go with spicer (which are kind of pricey) or neapco. Neapco parts are made in the USA and are the best thing next to spicer.

[marked for life]

Do you think that a 4400 lb car over a 3200lb car makes a different? With the nos shot I have I will be close to 650 to 700 lb rwtq. Should I go aluminum ?

[mrizzolo]

No need to go aluminum.. 3.50 x .083 steel tubing is strong enough. Just make sure its seamless. But if you went with aluminum you would have to eliminate the cardan joint.

[88MK7Man]

I used a Crown Vic police aluminum shaft, cut and balanced 58.5" flange to seal. T5 yoke installed. Set me back about $130 or so. Now if I can just get it installed. lol

[marked for life]

OK all info was very insightful but now I'm still jimbo in limbo , here is was I recently discovered . still only half of the puzzle ( maybe). A 1994 4.7 250 econoline 250 300-6 Cylinder has a 3.620'' wide by 1.063 cap size ( IS THIS THE 1350 SIZE) ? It's the front yoke universal joint going into a eod tranny ,this yoke has a vibration (dampner) ring which has a slightly larger ring (might hit the floor) which I will measure. Will this yoke fit into a AOD tranny? Is the spline count different ? How about the tranny tail shaft yoke bearing size fit ???. Still concerned about daily driving vibration issues... The only answer I can come up with is either tighten up any rear axle movement's up and down and every which way it can move or get rid of the the cardan joint... I'll tighten it up if it does'nt hurt my cars launch...OR CAN'T IT BE DONE...???

[SilverFox]

E40D 30 something spline will not fit your AOD 28 spline.

[marked for life]

Thanks silverfox, also tranny is still working great with not one issue. Would this tranny take ''1'' wot 1/4 mile pass into overdrive, i was out of motor when the car hit 117 mph on an 80 shot of nos (11.63 et) with a 1.600 60' (DOABLE OR DON'T EVEN TRY IT ??? Shootin for 1 10 second timeslip

[SilverFox]

I don't condone the use of OD in WOT situations.
You have a 2" Pro Series band with A+ servo, so there is not better that you can get.

[stnknlncln]

Hey guys. I'm installing a T-5 in my 88 in the next couple of weeks. I picked up a used drive shaft out of a crown vic for ten bucks. I wanna have it made this week. The question I have is, does anyone know the length I should have it made. Minus the diff and trans yokes ? Or overall, from end to end? thank you , Kevin

[re-Markable LSC]

Hey guys. I'm installing a T-5 in my 88 in the next couple of weeks. I picked up a used drive shaft out of a crown vic for ten bucks. I wanna have it made this week. The question I have is, does anyone know the length I should have it made. Minus the diff and trans yokes ? Or overall, from end to end? thank you , Kevin

58" from the seal to the flange.

[stnknlncln]

58 inches from the seal of the trans , to the flange of the rear? Thank you kind sir. Kevin

[stnknlncln]

Sorry for being a pain in the butt guys. But, I'm taking the shaft to the shop tomorrow. I wanna be sure. 58 1/2 inches from the seal of the T-5 to the diff flange ? Thanks again guys!