85 Quattro. Diff Done!

Posted on Apr 27, 2017

Well, the diff project is done, not without with some casualties. Read on……….

Our friend Carlos, a venerated old car genius, made a jig for the press to keep everything aligned while pressing in the notorious pair of small sub frame bushings. The large pair went in like you’d hope a bushing went in: easily.

Well that didn’t work and we destroyed one $50, only available from Germany bushing. Apparently there is always a 50% failure rate when pressing these in which is why we had a spare!

So we gave up with the jig and just used a bolt down the middle and lots and lots of patience. This took several attempts with each bushing as we eye-balled them intensely looking for any sign of them starting to twist.

Once they are happy they go in nicely, like you’d expect but the slightest mis-alignment causes them to rotate and if you persist, distort. It was a bit stressful as ruining one more would set us back a month. Once in we soon had the diff mounted in the sub-frame again.

Before we could reinstall the assembly in the car we still had one more bit of housekeeping to perform. One rather rough inner CV joint. Fortnately you can still get these from an OE supplier and we were able to work on it still attached to the car, though it was a little dark under there. Once cleaned the old CV joint came off with some elbow grease and a puller.

We assembled the new joint on the bench and packed it full of grease.

Then drove it home with a drift. They are surprisingly tight on the axle splines.

Then we were finally ready to throw this thing back in the car and tighten everything back up

Except for the lower control arm bushings off course, which have to be tightened with the car on the ground. Unless you have some BRAID wheels lying around that is. Don’t try this without proper wheels!

And of course, don’t forget to put some nice diff lube in it.

By then it was 1am so we waited till the next day to take it for a test drive

Before returning it to the stable with its friends.

Now the car needs an alignment and a tune. Still have some hesitation under load.