Question on setting up a rear end

M

mike802

Newbie
I am working on setting up a GM 10 bolt with a 7.5 ring gear. Today I was setting the pre load on the pinion bearing, which is supposed to be around 20 inch pounds. I had to use a 3/4 inch impact wrench because my 1/2 didn't have enough oomph. With the extra power of the 3/4 I went a little heavy and ended up with about 60 inch pounds of pre load. Does anyone know if this is going to be a problem? Should I take the pinion out and order a new crush coller, or will it be ok to run it a little tight?
 
By the way, you really should not be using an impact wrench to set preload. I use a large 1/2" drive breaker bar with a pipe extension on the handle. You also need to have a fixture to keep the yoke from turning while you tighten the pinion nut.
 
Yes, do not use an impact! I have heard of people :) taking the crush sleeve and placing it in a vise and squeezing it back a bit....:jeez:
 
Thanks guys . Guess I am going to take it apart and try again. I actually have a video, I think it is put out by Richmond, but it is at the shop and I am not sure. Anyway the guy in the video, named Paul uses an impact wrench to set the preload, that's were I got the idea. I tried using a breaker bar with a pipe, but I could not budge it, nor could my 350 ft pound 1/2" drive impact wrench. You guys must be much bigger and burlier than I am. I do have a fixture to hold the yoke, btw the guy in the video held it with his bear hands. Unrealistic, but the rest of the video had good info.
 
bearing preload on a pinion should be with in limits. did you use new or old bearings, pre load differs between new and old. the correct method is to hold the yoke and hand crush. also one shoud also set and recheck the pre load. to set take brass hammer strike pinion front and rear. also side bearing pre load is equally as important. there is alot more going on with set up hope i helped

sincerely john
 
John: Thanks very helpful! I went out to the shop last weekend and tore it back down. I had another crush collar and gave it one more try. I noticed that the collar I used the first time was actually thicker than the stock one, which could explain why I could not set preload with a breaker bar and pipe. On the second try I was able to set the preload by hand and I am using new bearings. Unfortunately I did not strike it on both ends with a brass hammer, this is the first time I have heard about it, but I see how it could be helpful. I am at about 23 inch pounds, so I am not worried about running to tight, but I will keep a close eye on it and make sure it does not loosen up. If it was going to I am sure it would happen right off. I noticed during setting the depth that the pinion would loosen a little if I spun it around, then I would retighten. I did the same for setting preload, but it didn't loosen at that point. On a different forum I asked the same question and a guy said if I ran the preload to tight I could expect over hearing and premature bearing failure at best, or it could explode like his did:clonk:
 
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