Pinion bearing preload, 742 carrier.

[Demonic]

I'm putting together a new set of 3.55's, Yukon R & P, New Timken bearings, new Auburn sure grip. I'm having trouble with the pinion bearing preload. It's either 55 in. lbs or about zero. The preload shims in the kit go in .005" steps. At .045" it has no preload, spins easy. At .050" it takes way too much to turn, a bit over 55 in. lbs. I did it twice with both ship sets to double check. Do I have to sneak up on it .001 or .002 at a time?

 

[Cranky]

Pretty much.....do you have some ones and twos?

 

[Demonic]

Nope. I'll have to get some.

 

[john-9]

your problem is the Yukon Gear ring and pinions for the 742 case -- the pinion is not machined correctly where the pinion bearing preload shims sit -- they cut an outboard radius there when it should have been undercut same as the stock factory gears --- this does not allow the shims to sit flat thus keeping the pinion bearing from seating into the cup --- if you go to the A-body forum and go to page 10 ,, go to April 14/2020 by plymouth 67 post then to page 2 of the post and read postings starting with #31 on posting #40 there is and excellent picture of the problem --- also on the B-body sight page # 7 post may 24/2020 for coronet 67 guy start reading at post #33 ,# 43 ,#46 same problem -- i have tried to find a contact number for Yukon gear so they can correct the mistake but no luck -- was hoping Cass could do something since he gets most of his stuff from overseas and probably has the contacts needed to correct this issue.

 

[5.7 hemi]

I like to have 18-24 inch pounds of rotational torque on the 8 3/4’s.