8 3/4” carrier bearing preload

[furrystump]

So I’m putting a spool in my 8 3/4” and was just reading up since it’s been awhile. I’ve set up 3-4 carriers in the past so pretty comfortable doing it. My question pertains to carrier bearing preload, IIRC I have used 90lbs of torque to set preload on the bearings, but just read about using case stretch between the bearing caps to set the preload. Is one way better than the other?
Thanks

 

[SGBARRACUDA]

I'm quoting Yukon gear set up info that the Author stated he has never seen a carrier bearing fail from to much preload on the carrier bearings. I set them up by tightening the adjuster on the ring gear side until I have .001 MOL backlash, then tighten the opposite side to the desired backlash, .007 MOL. Never had a problem with a carrier bearing failing.

 

[furrystump]

I read that also about not really being able to have to much preload. I will probably just stay with using torque value. Just first time I read about using case stretch. Thanks.

 

[SGBARRACUDA]

I read that also about not really being able to have to much preload. I will probably just stay with using torque value. Just first time I read about using case stretch. Thanks.

Only time I have used a case stretcher is on Spicer type rears like Dana 44,60,70 and GM 10 and 12 bolt rears. Never seen one for a third member.

 

[furrystump]

The idea is to measure how much the case stretches as a result of bearing preload. If the caps are spread .008-.010 apart that equals the correct preload. The picture showed the shaft of a dial indicator rod threaded into the bolt hole in the cap for the adjuster lock. With another rod over to the opposite cap and the dial indicator. Correct back lash and the correct amount of stretch and your are all set.

 

[Garrett Ellison]

The backlash setting is used to preload or stretch the third member to minimize ring and pinion deflection during acceleration and coast. I’ve never seen a torque setting, only the technique to set the ring gear side of the pinion at .001 or less backlash, and then adjusting the pinion side adjuster to achieve proper backlash on the gear set. The pinion side adjuster preloads/stretches the case the set amount required to achieve the backlash setting.

 

[mderoy340]

I'm quoting Yukon gear set up info that the Author stated he has never seen a carrier bearing fail from to much preload on the carrier bearings. I set them up by tightening the adjuster on the ring gear side until I have .001 MOL backlash, then tighten the opposite side to the desired backlash, .007 MOL. Never had a problem with a carrier bearing failing.

Agree, two notches after the adjuster contacts the cup usually does it. Make sure the caps are on and one bolt is snug.

 

[furrystump]

Back together, pulled it apart to swap the clutch limited slip out of it. Plan on using the limited slip with a set of 3:73 gears and my other case for drag week. Less gear will help with the road portion and because the “race” tire is 1 -1/2” shorter it will help on the track to lose a little rpm at the stripe. I was very lucky, found a bad wheel bearing, it was still spinning, but was definitely crunchy! It would have definitely been an issue. Had to improvise on marking compound.

 

[moper]

The backlash setting is used to preload or stretch the third member to minimize ring and pinion deflection during acceleration and coast. I’ve never seen a torque setting, only the technique to set the ring gear side of the pinion at .001 or less backlash, and then adjusting the pinion side adjuster to achieve proper backlash on the gear set. The pinion side adjuster preloads/stretches the case the set amount required to achieve the backlash setting.

X2...
Pattern looks good.