Craig C.

I need to pull my 89 C4's Front Diff due to confimed gear issues. Does anyone know the procedure for the removal?

Rocket Rob

I've never done it myself but I considered it when my front diff had a leaky seal. Its outlined well in the factory manual. Do you have access?

dfinnegan

Rob, what happened to your leaky seal?

Rocket Rob

Dave - I decided to pay my local dealer to replace the seal. It was the seal running the circumference of the output flanges. The work outlined looked like more than I wanted to take on at the time. Since that time, I've learned how to replace a steering rack, all of the associated tie rods and suspension struts.. Those were the items that I was worried about. If there is a next time, I may give it a try.

Are you having a problem with your front diff?

dfinnegan

I had a leak, but, knock on wood, it has stopped leaking.

I suspect that the fluid level got low, the seal got dry and leaked when left on the slope of my driveway. I topped up the case several times. Each time (maybe three in total) it took less to top up. Now it's dry and full.

I was looking at doing the job, but never did as it doesn't seem to need it now.

Craig C.

No Rob I don't have access to the Factory manuels. I wish I did, which is why I posted

The Axles are straight forward, the HR Sway is a pain, Dropping the "hogs head" out of it hole is
the issue.

Rocket Rob

Craig - I'll write myself a note to look up the procedure when I get home. I'll try to post the gist of it tonight.

Craig C.

Rob, THX I REALLY appreceate this. I miss my Rocket!
The 944 S is fun but, lacks the adreniline (Supercharger)
of my C4.

Sten

Craig,
The pain is trying to get the top two bolts that hold the Front Diff to the Torque Tube undone. Ideally, you need the car on a lift and an extension bar about 3 feet long, you can just get to the bolts to undo them. Putting them back is a whole lot more fun...

Rocket Rob

Factory procedure steps

Removal of front differential
1) Jack up vehicle
2) Remove pedal floor board
3) Disconnect steering column universal joint
4) Under car, remove front and middle floor panels
5) Remove retaining clamp from power steering lines
6) Unclip power steering lines from holder
7) Undo transmission bearing screw
8) Undo hex head screws from front axle cross members and side members and drop front axle
9) Remove stabilizer
10) Undo drive shaft at flant fron front axle final drive
11) Undo allen screw from front central shaft clamping sleeve and slide clamping sleeve along central shaft toward the rear
12) Undo upper fastening screws for central tube - front axle final drive - by pressing central pipe to one side with a suitable tool (do not damage lines).
13) Position gear box lever under neath, undo central pipe fastening screws and remove transmission

Installation
1) The rubber seal must be replaced on the facing surface of the central shaft before installing the front axle final drive. Apply glycerine to sealing disk before assembly. Tightening torque for hex head screws (M6 x 12) to 10Nm (7.5 ft-lb)
2) Check transmission oil and fill up if necessary
3) Clip lines into holder
4) Align front axle

I hope this helps.

Craig C.

Rob And Sten,

Guys Thanks ALOT, Just got it out and will do the replacement (among other things) in the morning.
Maybe I can still make the DE at VIR, I still have to install the drilled rotors and Hawk pads and get
'tech-ed'. Theres a couple of 348's & Zo6's I want to play with.
Again Thanks to both of you!