E-Bodies.org Cuda Challenger Forum

Technical Shop => Engine, Transmission & Rear End => Topic started by: Rbob on January 21, 2021, 09:11:22 AM

Title: another 8 3/4 contact pattern
Post by: Rbob on January 21, 2021, 09:11:22 AM
Changed from 4.10 to 3.73 and changed to Dr. Diff Sure trac-II

I used the pinion depth markings as a reference and and was .005 difference so I took out .005 shim stack.

Setup with dummy bearings and no crush sleeve. 
Backlash .08 and pinion preload at 9 in-lbs.

new bearings set at 24lb preload.  Factory service manual says 20-30 in-lbs  Why does is say 16-19 most places I find on the net?

Any changes needed?  If not I will install the new pinion bearings and recheck everything a last time.

Whats with the new front pinion bearing, seems awful tight, may have to heat a little to get it to get started.  Suggestions for installing that?


Title: Re: another 8 3/4 contact pattern
Post by: Chryco Psycho on January 24, 2021, 08:23:09 AM
I am no expert & have often struggled with this , to me the load side looks to high on the teeth should be more centered , the coast side looks great .
Could be a mistake on the inner diameter of the front brg or the new pinion diameter causing the tight fit .
Title: Re: another 8 3/4 contact pattern
Post by: Topcat on January 24, 2021, 09:35:45 AM
Maybe @jamesroney (https://forum.e-bodies.org/mlist/jamesroney_180) might know?

He understands this kind of stuff.
Title: Re: another 8 3/4 contact pattern
Post by: Rbob on January 24, 2021, 07:36:00 PM
I agree the drive side is a little high and closer to the toe side but better off on the toe side is my thinking.

I will take a pic of the final tomorrow,
Title: Re: another 8 3/4 contact pattern
Post by: Chryco Psycho on January 24, 2021, 08:57:09 PM
I believe the mesh could be deeper also so more in  he center & of the teeth & deeper so the load is closer to the root of the  teeth
Title: Re: another 8 3/4 contact pattern
Post by: davy442 on January 24, 2021, 09:11:30 PM
Here's a link to some pictures / descriptions
http://departments.weber.edu/automotive/YouTube/Weber_Ring_Gear_Contact_Pattern_Interpretation.pdf
Title: Re: another 8 3/4 contact pattern
Post by: Rbob on January 24, 2021, 09:52:22 PM
That is the best example I have seen, thank you.

It looks like toe-toe to me, so adding a little backlash should make the sweet spot, I will find out.

Title: Re: another 8 3/4 contact pattern
Post by: Rbob on January 25, 2021, 09:05:51 AM
This is after new pinion bearings and crush sleeve eliminator installed, not much change.

Title: Re: another 8 3/4 contact pattern
Post by: Chryco Psycho on January 25, 2021, 11:15:37 AM
I guess run it & see if it is quiet , i assume the backlash is correct ?