Guest Anonymous Posted February 14, 2002 Share Posted February 14, 2002 Changed the pinion seal on a 7.5 GM 10 bolt. I now have noise. What is the problem? Did I over tighten the yoke nut? Hurt the crush sleeve? Any help and the solution to fix appreciated. Quote Link to comment Share on other sites More sharing options...
denny411 Posted February 14, 2002 Share Posted February 14, 2002 Did you replace the crush sleeve? They must only be used once.also did you use an impact gun to reinstall? The proper way is to tighten the nut a little at a time, and alternatly turn the pinion with an inch pound tourque wrench to insure that you have the proper preload on the pinion bearings.If you over tighten it you will have to remove and replace with another sleeve.these sleeves are about 5 bucks at a gm dealership,so it pays to be patient. The only short cut to this would be to mark the pinion and nut before initial removal.and tighten till the marks line up but you must still replace the crush washer.It has spring tension against it and will not hold proper prelooad if reused.this will cause your pinion bearing to loosen and possibly make noise and wear out prematurely. Good luck Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted February 14, 2002 Share Posted February 14, 2002 One trick is to take a properly torqued/used crush sleeve to your machinist and have him make a duplicate (in essence it's not longer a crushable item but serves the correct purpose)....I forget the exact details but some hardcore GM racers do that. Perhaps someone here understanding that system futher can elaborate. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted February 14, 2002 Share Posted February 14, 2002 Did you paint the teeth with white grease and then check the pattern by turning the input shaft? Improper engagement (or the way the teeth ride on the ring gear) will cause noise as the teeth are making contact outside of they're designed area. This is a very important measurement and it will cause noise and premature failure if its done wrong. Just an opinion of course. Regards, Lone Quote Link to comment Share on other sites More sharing options...
blueovalz Posted February 14, 2002 Share Posted February 14, 2002 Thankyou Denny411. I've needed to change out the propeller flange on my conversion several times (same rear end), and never replaced the crush sleeve as I should have. With that said, I've never had a change of any sort with the rear end charateristics after performing the swap. Quote Link to comment Share on other sites More sharing options...
denny411 Posted February 15, 2002 Share Posted February 15, 2002 If you only removed the pinion nut and did not remove the carrier,all of your other clearances should be O.K (pinion depth/backlash) Quote Link to comment Share on other sites More sharing options...
Mike C Posted February 16, 2002 Share Posted February 16, 2002 Having taken apart and reassembled many used GM rears,you should have no problem replacing a seal and tightening the nut back down. You should snug it up until there is no fore-aft play, without the ring gear that is about 10-15in lbs to rotate. It is really pretty forgiving. It would be assinine to have to disassemble the entire diff and re-set the gears to replace a pinion seal. There is no need to check tooth pattern either, as you have changed neither the pinion depth (controlled with a shim between the pinion head and the root bearing, nothing to do with parts towards the front) or the differential case which is located by shims outboard of the carrier bearings. Either you have tightened it too far and actually damaged the bearings or not far enough and the thing is loose, ie it clunks. Does the noise change whether in drive or coast? The crush sleeve is for preloading the bearing. It is basically a separator between the large (root for lack of a better term) and the small pinion bearings. It is possible to run with out it, but LONG TERM reliability might be a factor, it would not have started making noise right away. I have even re-used them before, just put a metal rod through the middle and smack it on each side. Re-install as new. Wouldn't do it on a high dollar diff, but the rear in my Jimmy has over 50k miles on it that way. After breaking the 3rd r&p I got tired of buying new parts. As far as your noise, start with the easy things. Make sure you didn't leave any tools attached, make sure the ujoint straps are tight, make sure the wheels are snug, etc. Then move on to the diff itself. Removve the driveshaft and check for play. Then loosen the nut a little and check again and so on. With the rear tires off the ground, it should be fairly easy to rotate the pinion by hand unless the bearings are binding. If I had to guess, I'd say you didn't get it tight enough since the yoke is a press fit to some degree and you might have to armstrong it a little more than you might like. You did put the big washer back in, right? Quote Link to comment Share on other sites More sharing options...
denny411 Posted February 16, 2002 Share Posted February 16, 2002 My thought was, If the pinion nut is overtightened the bearings may howl from too much pressure on them. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted February 18, 2002 Share Posted February 18, 2002 Thanks for the help. I will road test to determine when the noise starts to come in. I did put the nut back on with an impact wrench and may have over tightened it. Quote Link to comment Share on other sites More sharing options...
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