Ok I have a shake in my car which seems to be coming from a welded axle which we may have made too long.
We tried the drivers side Fiero manual axle and it was too short. It popped apart and spewed needle bearings all over the street when the lower control arm traveled down to absorb the first bump.
Can I use a lumina minivan axle or does it have the wrong ends on it?
How to accurately measure for another axle?

I have not installed them or measured them yet but I have a set of Transport axles waiting to go into my next 4T60E project. I can tell you that the outer splines will not go into the Fiero rear wheel bearing.

Edit: There's some talk of axle measurements in Darth's installation thread: https://www.fiero.nl/forum/Forum2/HTML/053505.html

Also, make sure the Transport/Lumina APV has the overdrive trans.. Some don't and will have the wrong axles.

[This message has been edited by Stinkin_V8 (edited 09-20-2004).]

Order it from Ed Parks and be done with it. He has them in stock and made for you Fiero/4.9 swap.

Well, I would do that except that when I contacted him--he said his axles woould only work if my engine was mounted in the same place as where his kit puts it. We didn;'t use his mounts so there is no guaranty that ED's axle will work either.
we tried the manual Fiero axle----too short
we tried the pontiac 6000-----too long-----it works for the 4t60 but not the 4t60e
so I had one custom made---now it appears we had it made too long.

This is for the passenger side

quote Originally posted by jeffndebrus: small update; In another thread Darth Fiero describes using axles with a measurement between the cv joint boots. The short side (drivers side) he says 1-1/2 inches. Mine is 1" on the passenger side he says measurement between boots 3.5" is optimal. I just measured mine to be 5 3/4"

1/2" is not too different on the driver's side but this could mean that your engine/trans sits 1/2" further to the left than mine does. As far as the passenger side, even with your install I would say that distance should be no more than 4" (taking into account your driver's side 1" measurement). If you are getting a vibration it is probably due to the CV tripod bottoming out in the axle end which can lead to transmission and axle damage amoung other things. It sounds to me like you need a shorter axle. If you cannot find one the correct length, I would just have Moser Engineering make you a correct length unit for you. They cost about $150 using their "stronger" material. As far as measuring, does your 5 3/4" unit appear to be bottomed out? How hard was it to install? If it is bottomed out I would say you need one about 1-1.5" shorter, which Moser can make for you if you want. However, there are quite a few GM applications that have a similar length axle already, check out the 92-up right side C/H body cars (Bonneville, etc); these will plug into your tranny, but you will have to swap out the outboard tripod...no big deal just slide the boot back and undo the snap ring. Stock Fiero manual trans outer joints will go right onto this axle. Stock Fiero auto trans axles were smaller and will NOT work.

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power corrupts. absolute power corrupts absolutely.

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Thanks Darth,
looking at the axle in place---the inner boot accordian looks compressed toward the transmission. I suspect this is my problem.

My bad, thought you used all Ed's parts. Sounds like Darth got you going in the right direction. Hope you get it figured out. I'll be starting mine in a few weeks, now that I decided to keep the car(finishing the basement can wait and so can she!). Would you do anything different the second time around?

quote Originally posted by jeffndebrus: Thanks Darth, looking at the axle in place---the inner boot accordian looks compressed toward the transmission. I suspect this is my problem.

yea, I would be willing to guess that is your problem. With the correct length axle, your inner boot should look like your outer boot in relation to how much it is compressed with the car sitting on the ground.

Darth Fiero,
I found my receipt for the axle that we had welded up. The instructions on it are to take a stock manual fiero axle-drivers side---and retube it two inches longer than stock.---now we tried a stock one and it popped out and blew apart upon the first dip out the driveway.---so we are talking about 2" making or breaking this thing?

please advise

Best I remember on my 4t60e we used the bonneville axels. they had to be cut down but the shaft was splined far enough back all we had to do was cut a groove for the retainer clips. I can ask the guy htat done the axels for me if you need more specifics. I know it was bonneville axels bonneville inner joints and Manual fiero outer joints.

I did the 3800 SC swap with a 4T60E trans. The left side was a Left Fiero Manual axle and the right was the left axle form the donor car. A 95 Buick Riviera.
When mounting the motor and trans, I marked the center of the trans, between the tri-loble housings, (inner CV's). This center was 1" to the left, (driver's side), of the rear suspension center that I marked on the cradle. I also measured the bare axles. I think they were 14.5, (Fiero Manual trans left axle), and 15.5, (Buick Riviera left axle). I'm at work now, but I have all this info written down at home if you need exact measurements.
If your trans does not sit where mine does, you could total the lengths of both of my axles, then subtract the one you have that fits. The difference would be the length you need.
Hope this helps... sounds confussing as hell to me!
Kevin

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85 Fiero-based ASPP GT-40 MarkII. 3800 S/C, Auto, Held suspension all around with 2" drop spindles and sport fr. end. RCC bump-steer correction. Mr. Mike's interior.

quote Originally posted by Darth Fiero: Stock Fiero auto trans axles were smaller and will NOT work.

What's small about them? The Fiero AT axle shaft is a smaller diameter so the inner race from the axle's donor should be used along with the balls and ball cage from the donor. Could the Fiero outer race be installed over the donor's innards? Or is that what you meant when you said the AT Fiero axles being too small? I was hoping to be able to just replace two boot clamps and swap the outer races.

I could probably answer my own question just by tearing into the joints but I have two AT axle assembles with intact boots that I just hate to break up if they're no good for what I want to do with them. I'd rather give them to someone who can use them.

quote Originally posted by Stinkin_V8: What's small about them? The Fiero AT axle shaft is a smaller diameter so the inner race from the axle's donor should be used along with the balls and ball cage from the donor. Could the Fiero outer race be installed over the donor's innards? Or is that what you meant when you said the AT Fiero axles being too small? I was hoping to be able to just replace two boot clamps and swap the outer races.

The Fiero auto trans axles use smaller diameter and spline inner CV axle shafts, therefore the outer CV joint internals that spline onto this inner axle are smaller as well. To my knowledge, GM uses only 3 sizes/spline count inner CV axle shafts, the Fiero auto uses the smallest, the manual Fiero, along with MOST other FWD GM cars use the middle size, and the largest are used by the 4T65-EHD and 4T80-E cars.

Makes sense to me now, thanks (once again!) for the great info. Since the Fiero AT outboard CV outer race is too small to fit the donor's cage inside, I will leave my spare stock AT axles in one piece - maybe I can trade them to someone for a set of MT outer races.

I had same problem....look at bottom of this post....I solved it this way...clean and simple...

https://www.fiero.nl/forum/Forum2/HTML/051972.html

Check with BV Motorsports (Steve Vincent) - He built my 4.9 w/4T60E. Check the mebers list to PM him. If I remember correctly there is a stock Fiero axle and a Pontiac 6000 axle. Somewhere I have receipts and part numbers. My GT is an 87 wit an 88 cradle - that might make a difference as well.

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Kenny Hydock
Suffolk, VA

Unfortunately I have a 1985 car and as I understand it-the cradle is wider.
What I do not understand is this---the manual fiero axle was too short---it popped out and spewed needle bearings all over the place but a welded axle which is two inches longer is too long? I thought there was more travel room in the cups than that???

Hey jeff.... I just thought of something on the way home that might save you money on having to buy anymore axles.... This job will require 2 to 3 jacks and removing the back mount temperarly.... But I have the subframe with the tranny slotted.... But it will require moving the whole engine and tranny assembly over some... This can be done with the engine in the car.... But start with supporting a jack under the engine pan and one jack under the tranny pan... Also use a small peice of 2x4 about 5inch long also the 2x4 peices is to keep you from bending or puncturing the oil pan or tranny pan.... Now after that losen the 2 engine mounts the screws is accessable from under the car... After the 2 engine mount screws is out then loosen the tranny mounts also take the screws out from the engine mounts. Basically you will be moving the engine assembly over 1 1/2 inches for axle fitment .... You will need a bar to pry it over also.

I had to do this same thing once on my setup. I already notched the back tranny mount for you to do this.... This will save you money and headaches. Your going to have to redrill 2 new holes in the engine mounts......

This could not be done with the manuel axle because the pre 88 cradle is wider.

[This message has been edited by 86fieroEarl (edited 09-24-2004).]

EEEEE GADS Earl---
I think it would be easier to replace the axle. I don't want to mess anything up by moving the whole assembly around. I appreciate the suggestion though.
Jeff

Bump...

quote Originally posted by jeffndebrus: Unfortunately I have a 1985 car and as I understand it-the cradle is wider. What I do not understand is this---the manual fiero axle was too short---it popped out and spewed needle bearings all over the place but a welded axle which is two inches longer is too long? I thought there was more travel room in the cups than that???

is it possible for two inches to make one axle too short and another too long? I thought there was more travel in the cups than that?

bump

quote Originally posted by jeffndebrus: is it possible for two inches to make one axle too short and another too long? I thought there was more travel in the cups than that?

There is...but that travel is meant to allow for variations in the length of the axle as the suspension travels up and down; at the top and bottom of the suspension travel, the axles have to be a bit longer than in the center (or "at rest") position, which is why, when the axle was too short, as soon as you hit the dip leaving the driveway, the axle length effectively changed from the position it was in when the car was resting. It sounds as if you measured the axle length after the first time you tried to drive it without taking into account the suspension travel (very easy thing to overlook, btw; hard to think in three dimensions at the same time) and I'd be willing to wager the car was on jackstands at the time, with the suspension in the extended position (hanging down, no weight on the tires). The splines on the axles not only provide engagement with the transmission and spindles, but also function as a sort of universal joint whose function is to transmit power as it slides in and out, as opposed to lateral changes in angle like a univeral joint allows. I think you already understand all this, but sometimes it helps to have one's memory tugged in a different direction, to help you see a problem from another perspective so as to come up with a solution. Kinda like using a mirror to find a bad freeze plug.
Knowing that the axles are too long, I can only imagine the degree of stress on the metal. The axles are probably flexing like a torsion bar as they rotate, which would cause the severe low-speed vibration/wobble you were feeling; if you try to drive it as is, sooner or later something is going to break rather spectacularly, probably with a loud bang and pieces of flying metal with bulletlike velocity.
HTH, Tony

(Good mornin,' Jeff.)

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88 Formula, "Asphalt Aviator"

"I've seen em---they're little fellers. You know, the Artesians..."
---caretaker at Olympia Brewery

[This message has been edited by Vonov (edited 09-26-2004).]