rear end whine
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Teching In
Joined: Jan 2007
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From: Fighting Illini
rear end whine With a stock 3.23 geared 125k mile rear end, is it just natural for the rear end to start to whine? Mine just started the other day and its really bothering me and I want to fix it but am unsure of what exactly is the cause and what needs to be fixed. The pinion seal was leaking for a long time before I got it fixed 2 months ago and im wondering if that had anything to do with it, either the long leaking period or the actual repair itself. Thanks for any help guys.
The rear in my Blazer (130k miles on it) just started whining for a similar reason. If it’s whining constantly and at all speeds then you probably have some damage to the gears and/or bearings due to the excessive heat that was generated while you were low on fluid. If that’s the case you can either run it until it eventually breaks, replace it with a junkyard rear, or my personal favorite option……..swap it out for a 9” 
If the preload on the pinion has backed off, you will start hearing a progressively worsening whine over time. If the pinion seal was replace the companion flange was taken off completely and put back on. Preload may not have been correctly set.
Thread Starter
Teching In
Joined: Jan 2007
Posts: 18
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From: Fighting Illini
Well, would any of the possibilities be causing damage to the LSD? I figure the rear has 125k on it and is in need of some work, so im going to get new gears and bearings in there but DONT want to have to replace the LSD if possible.
Side question...is going from 3.23's to 3.42's going to be noticeable? Either in performance or fuel mileage. Car is simply a daily driver, no track duty, but I wouldn't mind a little performance boost with little to no penalty in MPG.
Side question...is going from 3.23's to 3.42's going to be noticeable? Either in performance or fuel mileage. Car is simply a daily driver, no track duty, but I wouldn't mind a little performance boost with little to no penalty in MPG.
