PDA

View Full Version : Useful items from AT.net-Changing the rear diff mount



Nitro_Alltrac
08-23-2010, 03:16 AM
In an effort to preserve the useful information and data on our cars that is on AT.net, I've been pull the site down. I'm sorting through the stuff and will be posting up the useful articles and postings. This it the first one. It covers how to change the rear diff mount.

Disclaimer: I did not write this article. I am merely posting it here for use.

WRITTEN BY Nathan Fogg


The following are instructions on how to replace the rear differential
support cushion often responsible for "rear end clunk".

PLEASE NOTE. I AM NOT A LICENSED MECHANIC. THESE INSTRUCTIONS ARE FOR
REFERENCE ONLY AND I DO NOT TAKE RESPONSIBILITY FOR ANY DAMAGE DONE TO
PROPERTY OR BODY AS A RESULT OF THEIR USE.

I used a 1992 Toyota Celica shop manual as a reference and the torque
values given are from this manual. The instructions are in order of
disassembly with bolt torques given for re-assembly. All the listed
steps are necessary. I wouldn't list them if it would have worked
otherwise.

1. Visually inspect the dampener, located on the rear end of the
differential with two 19mm bolts in it just in front of the fuel tank.
If you feel you need a new one due to "rear end clunk" or poor visual
appearance go buy a new one (part number 52291-20010 for a ST-185;
roughly US$100) or have arranged a place to have the cushion
re-vulcanized.

2. If you have access to a hoist which lifts the car by its wheels, this
would be best. I used 2 jack stands and a floor jack. Raise the car
high enough so you can comfortably work under it. Place a platform under
each rear tire such that the tires touch the platform approximately 100mm
before the car is supported by the jack stand. ALWAYS USE A LOCKED JACK
STAND, NEVER A LIFTING JACK WHEN WORKING ON YOUR VEHICLE. The platforms
allow the half shafts to be in a more neutral position when you later
lower the differential. Otherwise they would contact the suspension.

3. Under the car. Remove the four bolts (17mm 54lbf-ft) holding the rear
cross member.

4. Disconnect the drive shaft from the differential. Four bolts (14mm 53
lbf-ft). Secure the drive shaft to the bottom of the car to avoid
straining the CV joint at the other end.

5. Remove the two 19mm bolts (108 lbf-ft) and four 14mm bolts (???
lbf-ft) from the rear diff cushion.

6. Loosen the four bolts holding the differential to the sub-frame. The
bolts are 17mm while the nuts above the diff are 19mm. I don't
understand either. (74 lbf-ft)

7. Support the differential with a floor jack with a piece of wood
in-between.

8. Remove the four vertical differential bolts loosened earlier.

9. Slide the differential as far forward as possible and then lower
approximately 50mm.

10. The diff cushion should slide out to the RHS of the car.

It's a real good idea to clean all the bolts and nuts / tapped holes
prior to re-assembly. Not only does it allow quick threading in these
awkward positions, but it ensures proper torque measurements. Consider
replacing bolts which appear to be severely corroded. Be sure to buy the
proper grade bolt if it's not the Toyota bolt. Usually grade 10.9 or
higher. Another hint is to start all your bolts/nuts before tightening
them. This nearly assures proper component alignment.


Brought to you from the GT4 List