Fiero Custom CV Axles OD Auto Transmissions

HOW-TO Build Custom CV Axles for Automatic OD Transmission Swaps

1984-88 Pontiac Fiero

Disclaimer and Notes:

The information provided here is for reference purposes only. The parts discussed here may or may not work for you depending on the placement of your engine/transmission package in the car. Engine/transmission placement is CRITICAL to axle lengths and differs from car to car depending on what mounts are used. Furthermore, axles that can be purchased at most auto parts stores MAY NOT WORK with these instructions because of aftermarket manufacturer's design changes. I only use factory axles, factory axle parts, or remanufactured axles that use factory parts in my swaps and these instructions were written for use with these parts only. I suggest you get your donor axles off of a parts car from a junkyard or other source so you can verify their origin.

440-T4 or 4T60 (non-electronic) Automatic Overdrive Transmissions using a stock Fiero engine (in stock location)

NOTE: Using stock Fiero engine mount, stock 92 Pontiac Bonneville front transmission mount, and stock Fiero rear transmission mount bolted to 440T4/4T60 mount bracket (on transmission) w/ mounting holes in cradle elongated so the mount studs line up. Some elongating of the front transmission mount holes in cradle may also be required. Make sure engine mount bolt holes are lined up before determining if you need to elongate any of the transmission mount bolt holes.

Driver's Side:

You will need one LEFT side CV drive axle from a 1989 Pontiac 6000 with the 2.8L V6 vin W and JA1 light duty brake option (no ABS) with the 4-speed auto OD trans. These vehicles also came with the 125-C 3spd auto trans and a JA8 heavy duty brake option; and axles from this car won't work!. No further modification to axle should be required.

Passenger's Side:

You will need one RIGHT side CV drive axle from a 1989 Pontiac 6000 with the 2.8L V6 vin W and JA1 light duty brake option (no ABS) with the 4-speed auto OD trans. These vehicles also came with the 125-C 3spd auto trans and a JA8 heavy duty brake option; and axles from this car won't work!. No further modification to axle should be required.

4T60-E and 1997-up 4T65-E (non-HD) Electronic Automatic Overdrive Transmissions

Driver's Side:

If you have a 4T60-E (non-HD) transmission, use an OE Stock or Replacement complete CV axle assembly from Driver's side of a 1994 Chevy Beretta, Chevy Corsica, Pontiac Grand Am, or Olds Achieva with the 3100 V6 engine and 4T60-E 4spd auto OD trans. These vehicles also came with the 125-C 3spd auto trans, and axles from this application won't work! The inner axle you need to use should measure about 1.5-2.0" between the CV boots. The inner tripot end may need to be swapped with one that is compatible with your trans. (Earlier 4T60-E transmissions did come with a different spline count shaft on the driver's side vs. later 4T60-E's and 4T65-E's. So if this part you buy does not fit your trans, you may need to use the inner CV tripot end from the car your transmission came out of.
If an ABS Reluctor ring is present on the outer tripot joint of the 94 CV axle, remove it using a drift and hammer or shop press.
If you have a 4T65-E (non-HD) transmission, get a driver's side CV axle from a 1999-2001 (or possibly newer) GM front-wheel-drive minivan that had the 3400 V6 and the 4T65-E transmission. NOTE: Earlier minivans used a 4T60-E transmission; the way to tell them apart is the 4T60-E has a vacuum modulator on the front of it which mounts just below the transmission electrical connector and both face the front of the vehicle. The 4T65-E has no vacuum modulator and the electrical connector for it is on the top of the driver's side of the transmission and faces the driver's side of the car. Remove the outer tripot end and CV boot from this axle and install the CV boot and outer tripot end from a any side of a 84-88 Fiero manual trans CV axle.

Passenger's Side:

For the outer CV joint (part that couples with the wheel bearing hub) both parts are going to be stock 84-88 Fiero manual trans items. Auto trans Fiero components will not work here.

Concerning the INNER CV joint portion and CV inner shaft itself:

Inner CV tripot is going to be from any side of a 84-88 Fiero manual trans CV joint.
Inner CV tripot joint is going to be from any 84-88 Fiero manual trans CV joint.
Inner CV shaft is going to be from a late 90's thru early 00's GM W-body car with the OD auto trans (non HD). Concerning this shaft, the overall inner shaft length should be about 14.0-14.5" (as disassembled from the CV tripot ends), or the measurement between the CV boots should be about 3.0-3.5".

SPECIAL NOTES:

-The Fiero OEM inner CV shafts will not work with the electronic OD transmissions because they are of incorrect length.

-The some donor CV inner shaft's snap ring grooves may be spaced differently than what you will find on the Fiero parts. Although they are spaced differently, they will still work with the Fiero CV joint components.
-If you have a 4T60-E HD transmission, you may need to use the donor inner tripot ends from the 4T60-E HD transmission you got.

1997-up 4T65E-HD Electronic Automatic Overdrive Transmissions

For this job, you should have a pair of OEM Fiero manual trans axles on-hand for parts. Fiero auto axles are made with smaller diameter shafts, and some aftermarket replacement manual trans axles for the Fiero are also made with smaller parts so they MAY NOT WORK. Furthermore, aftermarket axles may be made using differently designed parts and may not work in this application.
You will need one LEFT (Driver's) SIDE COMPLETE CV shaft from a 1999-2001 (or possibly newer) GM front-wheel-drive minivan that had the 3400 V6 and the 4T65-E transmission. NOTE: Earlier minivans used a 4T60-E transmission; the way to tell them apart is the 4T60-E has a vacuum modulator on the front of it which mounts just below the transmission electrical connector and both face the front of the vehicle. The 4T65-E has no vacuum modulator and the electrical connector for it is on the top of the driver's side of the transmission and faces the driver's side of the car. Remove the outer tripot end and CV boot from this axle and install the CV boot and outer tripot end from any side of a 84-88 Fiero manual trans CV axle. The inner axle you need to use should measure about 2.0" (give or take 1/2") between the CV boots. The inner tripot end of this axle should plug right into the driver's side of your 4T65-E HD transmission (even though the axle came out of a non-HD 4T65-E). The driver's side inner tripot ends used in the 4T65-E and 4T65-E HD transmissions are the same.
You will also need an inner axle shaft from a late 90's thru early 00's GM W-body car with a V6 engine and auto trans (non-HD), this is going to be for the passenger side axle you are going to make. Concerning this shaft, the overall inner shaft length should be about 14.0-14.5" (as disassembled from the CV tripot ends), or the measurement between the CV boots should be about 3.0-3.5".
For the outer CV joint (part that couples with the wheel bearing hub) on BOTH sides, both parts are going to be stock 84-88 Fiero manual trans items. Auto trans Fiero components will not work here.

Concerning the INNER CV joint portion and CV inner shaft itself...

The Driver's side inner CV tripot end, joint, boot, and inner axle shaft that came stock on the minivan axle will be what you are using and should plug right into your 4T65-E HD transmission. The only thing you are changing on this axle is the outer CV end/joint, and boot. You will use 84-88 Fiero manual transmission parts here so this axle will plug into and work with your Fiero wheel hub bearing.
The Passenger's side inner CV tripot end & CV boot is going to be from a W-body 4T65-E HD trans.
The Passenger's side inner CV tripot joint is going to be from any OEM 84-88 Fiero manual trans CV joint.
The Passenger's side inner CV shaft is going to be from the passenger's side of a late 90's thru early 00's GM W-body V6 car (using non-HD auto trans).

SPECIAL NOTES:

-The HD inner CV shafts and outer CV joints will not work with the Fiero components because they are of incorrect length and are too large of diameter.

-The some donor CV inner shaft's snap ring grooves may be spaced differently than what you will find on the Fiero parts. Although they are spaced differently, they should still work with these CV joint components.

-When the CV shaft / joint assembly is inserted into the HD CV tripot; there should be virtually NO PLAY (twisting) although the joint should smoothly slide in and out of the tripot (plunging action).

Custom Axle Building Suggestions

When building your own axles, you can use whatever CV boots you feel fit and seal the best. The larger boot clamp must be CV shaft-specific part (to clear the knuckle) but the smaller diameter clamp can be a regular hose clamp if you don't have access to replacement small CV boot clamps. NAPA Auto Parts sells new CV boot clamps. Take them a set of old ones you need so they can get you the correct diameter replacements. There is a special CV boot clamp crimper tool available you should use when crimping new CV boot clamps or recrimping used CV boot clamps. I suggest cleaning all used components with mineral spirits and then drying with compressed air. You can then test-fit your custom built/length axles on the car before installing the grease and boots to check for proper length. The inner tripot bearing should not bottom out in or come close to coming out of the inner tripot end throughout all ranges of the suspension's motion. Use NEW CV joint grease when assembling. New CV components can re-use grease as long as no foreign material contaminates the grease or components. When you build your axles and install them into the car the boots should look normal; that is so they don't look extended or compressed excessively. The CV shaft needs to be able to extend and compress into/out of (plunging action) the inner CV tripot to compensate for suspension geometry during normal driving. The CV shaft assemblies should also not bind with the car moving on the ground nor when the car is jacked up and the wheels are free-wheeling. Also, make sure you don't have any CV boot leaks and that there is not any CV joint play when you turn the wheel back and forth.

Breaking your axles? Need stronger inner shafts? Check out: http://www.moserengineering.com/. Provide them with your existing inner shaft and/or specs and they will build a new one using stronger material of your choice. They can also build custom-length axles.

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revised: 4-25-2011