4A silid axle rebuild

[Sam]

I have stripped down the solid axle on my 4A and found a 40thou spacer behind the large pinion bearing and no shims under the bearing race as indicated in the parts book.

Reading Pete Cox's article on the Technicalities CD he stated that this shim should be removed on solid axles as it was only fitted to IRS ones.

 

I don't believe the axle has been previously rebuilt, judging by the condition of the crownwheel! Therefore I can therefore only assume it was there from new.

 

Can anyone shed light on this, should I replace the shim with equivalent thickness ones under the race or rebuild as it was?

 

Incidentally I was able to remove the axle (minus halfshafts and backpates) horizontally through the wheel arch (a doddle)and not by threading it through the chassis as shown in the manual.

 

Sam

[Rhodri]

Sam, the large shim/s between the pinion head bearing and the axle casing is to position the depth of the pinion towards the centreline of the crownwheel. This allows for machining tolerances, and the measurement is arrived at using special tools. However, if you are retaining the same crownwheel and pinion, and if your new pinion head bearing is the same width as the old one I would think your original shim should suffice.

 

The other shims are between the spacer and the pinion flange bearing. These are to set up the preload on the pinion bearings. You will also find shims next to the carrier bearings, where the half shafts enter, these control the depth of mesh of the crownwheel and pinion and the preload on the diff carrier.

 

I am no expert at this, but have had a bit of success with Ford diffs and this weekend with a Toyota diff ( except for a broken toe ), and I would readily accept that Pete Cox has forgotten more than I will ever know about diffs!

Rod.