Seting backlash on a 901 diff.

[Sebring]

My differental is really noisey and I think the ring gear needs
to be moved closer to the pinnion gear. Where do the shims go?
Where can I buy shims if I even need them?

[yetibone]

I don't think you can put shims in a 901 diff. If its possible, they would go on the driven shaft, behind the pinion bearing.

Mine had none behind the pinion bearing, and no place to put any on either side of the differential carrier.


Yetibone

[Michael Ghia]

Setting up a 901 backlash, preload and the mesh pattern is not for the faint hearted.
You need to have the gearbox stripped right down and have just the diff, crown and pinion in the case along with the correct tools and know-how to do it.
Before you dive in, I would start with the obvious, change the oil (Swepco just can't be beat!) and see if it quietens down.

Gearboxes are funny things when it comes to noise, you can completely rebuild a gearbox with new bearings, gears, syncros etc and still have the same noise. It would probably be more cost effective to look for another box.

901's are not a silent running box. I remember running mine and even after a rebuild, there was still some running noise (not incredible but there all the same) although, that said I was running the car without a panel above the gearbox so I could hear more than you would in a stock bug.

I don't mean to be pessimistic, but it's a lot of work for a noisey gearbox.

MG