[davidpaul]

I deleted the post I started yesterday as the information was incorrect.

After much adjusting with different size shims, checking bearings and gear teeth, finding no obvious problems.
Today I have bought some engineers marking blue which I have used to find the contact patch for the teeth,
as you can see from the picture the contact patch is on the toe of the tooth, it should be near the centre.

What are your thoughts ? (it doesn't rotate very smoothly when assembled)

[NMKawierider]

Right. The pinion gear should enter and exit contact more centered on the ring(crown) gear. Now the question is...how to make that happen and with the proper backlash. I am still looking forward to an explanation to the adjustment on the exterior and how it effects the carrier if at all. Your observations and photos would be very welcomed.

[Cosmosdan]

On others I've done, shiming the pinion moves the contact area. Looks like it needs to move back and then shim ring in to get proper play.

[davidpaul]

I think the external adjuster is only to stop the crown wheel moving to far away from the pinion under extreme pressure, the gap between the end of the adjuster and the back of the crown wheel is 0.5mm (if my memory serves me right) which is easy enough to measure when the diff is striped down.

On mine there is no evidence that the "adjuster" has ever touched the crown wheel.

Setting the back lash is easy enough if you have a selection of shims, I have found the inner shim to be a pain to set as it has to be measured when assembled, I have used plastigauge which helped with this. Although it would seem the inner shim doesn't need to be an exact fit (in my opinion)

I'm going to have a look at the pinion adjustment later, it look's like there is an threaded bearing stop on the inside and shims on the outside to set the preload.

I'll take a few pictures later

[davidpaul]

On others I've done, shiming the pinion moves the contact area. Looks like it needs to move back and then shim ring in to get proper play.

Yes, that's my next thing to look at

[Bobbed06]

You do want to make it feel nice to rotate, the smoother the quieter. to me it looks like maybe shimming the ring away from the pinion more, and then shimming the pinion deeper into the ring will get you closer to center which is ideal.

Play with shims on both til u find the pinion favors the center of the ring gear teeth. Keep us posted with pics, and info!

[davidpaul]

Yes that's the plan 

I have had another look and it's easier than I thought to adjust the "pinion distance" undo the four bolts holding the front cover on and the whole unit comes out in one piece (picture one) just add or remove shims to achieve the correct pinion distance.
The second picture shows the shims that adjust the backlash, the third picture shows the inside of the external adjuster.

I only have two shims to adjust the pinion distance so I'm going to fit them and check where the contact patch is, I think I'm going to refit the diff and test as it's going to be three or four weeks before I can get some more
 shims.

Just to clarify I need to move the pinion out or further away from the crown wheel to bring the contact patch between the two gears closer to the centre of the teeth.

[Bobbed06]

You need to shim the ring gear AWAY from the pinion gear more by removing one of those shims,  then shim the pinion gear CLOSER to ring. This should get you riding more in the center of the gear.

[Bobbed06]

Just a side note here.....That ring gear looks in really great shape for having almost 2500 miles on it (is that about right)

All of the parts in that assembly look pretty heavy duty to me. That "adjuster bolt" you have mentioned may very well be a ring gear support to prevent deflection under heavy impacts to avoid breaking the ring gear.

Please post pics of that adjuster bolt you speak of, and how a mock up pic of how it plays a part in assembly.

[davidpaul]

I think I may have been mixed up about moving which part to achieve the right result after looking at this, it would appear I have to increase the backlash, I've been trying to keep the backlash to a minimum as the service manual seems to suggest maybe I need to forget the manual and just work towards getting the correct contact area ?

Thoughts please

And yes she's on 2500 miles now, the only problem I would like to improve is this noisy diff, very happy with her apart from the rear diff noise.

[Cosmosdan]

It can get confusing. Try holding the parts as they would be assembled. Move the pinion in and out and notice where it touches. The teeth are not straight. Just doing this might clear up what happens when you move the pinion in and out and the ring side to side. Your just trying to get to the happy spot in the middle like in the picture.

[davidpaul]

I think I may have sorted it the first two pictures are of the gear mesh and the last two are of the adjuster, you can just see the head of the adjuster between the alloy case and the crown wheel.

[Bobbed06]

Its hard to see but yes I think you have found the sweet spot. Try checking it with some cheap paint rather than that machinist blue ink.

Remember dont forget to set your adjuster lash to spec 0.5mm once you have settled on the mesh.

[Bobbed06]

How does it feel spinning it by hand now? It should be notably smoother and less notchy. Great job on taking this on and fixing it!

be sure and take how to pics of assembly of the diff, lash measurement and setting that, and reinstallation so that others may benefit from your hard work! 

[Cosmosdan]

For checking contact I use a sharpie marker