Thread: Diff contact pattern

Can't you adjust the backlash by adjusting the carrier side bearings?

Originally Posted by malrv1

Can't you adjust the backlash by adjusting the carrier side bearings?

I have done exactly this, by one 'notch' on each side, problem is I end up with 2 thou of backlash

Doesn't seem to be a pinion height problem since the contact is roughly even on both sides of the tooth. I assume that's the way it was running? Do you have room for one more notch of preload?

With differential tooth contact you need to get even pattern on the load side of the tooth that is it will need to be middle of the tooth in and out and middle up and down. With a P38 the front diff actually drives backwards so it needs to be central on the back side of the tooth when checking. It looks like you need to go deeper with the pinion to get a better contact, closer to the centre. Once you have the correct tooth pattern adjust the side bearings away from the crown wheel until you get .005" - .010" backlash remembering to adjust the side bearing equally on both adjusters to keep the correct pre-load on the bearings. New bearings have more pre-load than old bearings which will have worn slightly.
Gippy

Here's a helpful chart from Spicer. I think you need to increase pinion depth, but I am no diff guru.
http://www2.dana.com/pdf/5717.pdf

Originally Posted by Gippslander

With differential tooth contact you need to get even pattern on the load side of the tooth that is it will need to be middle of the tooth in and out and middle up and down. With a P38 the front diff actually drives backwards so it needs to be central on the back side of the tooth when checking. It looks like you need to go deeper with the pinion to get a better contact, closer to the centre. Once you have the correct tooth pattern adjust the side bearings away from the crown wheel until you get .005" - .010" backlash remembering to adjust the side bearing equally on both adjusters to keep the correct pre-load on the bearings. New bearings have more pre-load than old bearings which will have worn slightly.
Gippy

thanks

Looking at the various contact pattern guides I was under the impression I had to decrease backlash to get the pattern closer to the toe end?

It looks very well centered root to face?

This is a Ring and Pinion pulled from a brand new defender

I have tried to decrease backlash to try and center it but I end up with <2thou backlash

Originally Posted by 2stroke

Doesn't seem to be a pinion height problem since the contact is roughly even on both sides of the tooth. I assume that's the way it was running? Do you have room for one more notch of preload?

I have tried, I agree that the pinion depth looks spot on, reused previous shim and it seems to be good,

When trying to adjust the backlash that extra notch I get close to no backlash atall,

I am tempted to leave it as is?!

Originally Posted by Duarte19

I have tried, I agree that the pinion depth looks spot on, reused previous shim and it seems to be good,

When trying to adjust the backlash that extra notch I get close to no backlash atall,

I am tempted to leave it as is?!

I was thinking about 1 more notch preload as in tighten the crownwheel side nut 1 notch and see if it closes a little.