Pre-load on differential bearings on a 6 speed tranny

[titaniumdave]

I am re-building my 6 speed tranny and keep getting different readings on pre-load on the used bearing on my 6 speed tranny. I am installing a 4.23 type-R R&P in my 6 speed, using a 91 LSD body. I am using the bearings and races from the 91 diff, which are in good shape, put them in the 6 speed case, torqued it all together and am testing the pre-load with a scale, pulling on the end of an 8" lever. The readings are between 3 and 4 lb. = 24-32 in. lb. Spec is 17-26 in.lb.

Is this OK for used bearings? how much lube should be on the bearings? I can remove .0015" of pre-load by swapping shims, seems like this is the next looser I can go, should I do this or keep with the parts a hair tight, expecting them to 'work in'.

 

[titaniumdave]

Well, I might have answered my own question. I worked some more MTL into the bearings and spun everything around a couple of dozen times and the pre-load has dropped to 18-22 In lb., right in the spec range, so I guess I am good to go.

Would still like an opinion if someone thinks I am making a mistake.

Thanks,
Dave

 

[NSXTech]

You are right on. The preload is checked with the bearings as lubed as they can be with a lubricant no heavier than what it is designed to run in road use.
Technically speaking, the spec is a guess anyway because it is for new bearings, but havibg done this a few times, I can tell you that your preload is exactly where it should be.

HTH
MB

 

[titaniumdave]

Thanks Mark,
I appreciate the confirmation!

Dave