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 and axle parts in my swaps and these instructions were written for use with factory 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

Driver’s Side:

You will need one LEFT SIDE CV axle shaft from 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 car won’t work!. To make sure you have the correct axle, measure the distance of the shaft between the two CV boots; it should measure about 1.5″. Remove ABS reluctor ring using drift and hammer or press.

Passenger’s Side:

Use OE Stock or Replacement complete CV axle assembly from Passenger’s side of a 1984-88 Fiero 125-C automatic.

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

Driver’s Side:

Use 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 car won’t work! The inner axle you need to use should measure about 1.5″ between the CV boots. Remove ABS reluctor ring using drift and hammer or press.

Passenger’s Side:

For the outer CV joint (part that couples with the wheel bearing hub) both parts below (“1″ and “2″) are going trans Fiero components will not work here.

Concerning the INNER CV joint portion and CV inner shaft itself, use the following picture and notations:

Inner CV tripod (1) is going to be from any side of a 84-88 Fiero manual trans CV joint.
Inner CV tripod joint (2) is going to be from any 84-88 Fiero manual trans CV joint.
Inner CV shaft (3) is going to be from a 2001 Chevy Impala 3400V6 4T45-E auto trans. Concerning this shaft, the overall inner shaft length should be about 14.5″ (as disassembled from the CV tripod ends), or the measurement between the CV boots should be about 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 2001 Impala CV inner shaft’s snap ring gooves are 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.

1996 4T60E-HD and 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 SIDE inner axle shaft from 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 car won’t work!. The inner axle you need to use should measure about 1.5″ between the CV boots.

You will also need an inner axle shaft from a 2001 Chevy Impala 3400V6 4T45-E auto trans. Concerning this shaft, the overall inner shaft length should be about 14.5″ (as disassembled from the CV tripod ends), or the measurement between the CV boots should be about 3.5″. For the outer CV joint (part that couples with the wheel bearing hub) on BOTH sides, both parts below (“1″ and “2″) 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, use the following picture and notations:

Both Driver’s and Passenger’s side inner CV tripod (1) are going to be from the HD trans you are using in your swap.
Both Driver’s and Passenger’s side inner CV tripod joint (2) are going to be from any OEM 84-88 Fiero manual trans CV joint.
Driver’s side inner CV shaft (3) is going to be from a 1994 Chevy Beretta 4T60-E.
Passenger side inner CV shaft (3) is going to be from a 2001 Chevy Impala 4T45-E .

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 Fiero manual trans inner CV shafts are the correct diameter but are not the correct length for use with the HD transmissions when mounted in a Fiero.
  • The 2001 Impala CV shaft’s snap ring gooves are spaced differently than what you may find on the Fiero CV shafts. Although they are spaced differently, they will still work with these CV joint components.
  • When the CV shaft / joint assembly is inserted into the HD CV tripod; there should be virtually NO PLAY (twisting) although the joint should smoothly slide in and out of the tripod (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 dia clamp can be a regular hose clamp if you don’t have access to the small CV boot clamps. I suggest cleaning all used components with mineral spirits and then drying with compressed air. 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 they don’t look extended or compressed excessively. The CV shaft need to be able to extend and compress into/out of (plunging action) the inner CV tripod to compensate for suspension geometry during normal driving. The CV shaft assy’s 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.

Need information on basic CV axle disassembly and assembly? Download it here.

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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