Overheating Differential???

[Wheels]

Okay got a good one for you...I made a trip to the other side of OKC yesterday (40 miles one way) and noticed that the K5 started to act funny (seemed to loose some power and act like something was binding). Got out and checked the front hubs, they were warm, not hot. Checked the t-case, again was warm, not hot. But the rear differential was hot to the touch (outside air temp was only 89). After it cooled down, drove it back home. Jacked it up and the rear seemed to be a little hard to turn so I let it cool down again. Checked the fluid level and it was normal. The only thing I can think is that the rear is about to come apart. I have Precision Gears 4.10 (thick) gears (3.07 carrier), stock gov locker, 12-bolt, synthetic gear lube, 33" tires. Also, after it warms up, there is a vibration/humm that starts at about 70 mph and the longer it runs, you can start to hear it in lower operating ranges and it becomes more pronounced. Swapped out driveshafts (I have a brand new, balanced spare) and it still did the same. Went to the lake today (took the Z-71) and after towing the boat and traveling, the rear end on it was only warm at best. My bet is the blasted rear is about to come apart. I know that the lower ratio's (numerically higher) will run a little hotter, but I think that this is a little to hot. Any opinions, I open to any and all suggestions. It's late and I'm heading off to bed, I'll check back in the am.

 

[RaisedK5]

If its not making real loud horrible noises like my transfercase does, i would suspect that the bearings may have gone bad, unfortunately, if the bearings chucked some chunks the gears could be fried too, first i would stop driving it, hard i know, my baby's been parked for a week, and when you get a chance pull the cover, drain the oil thru some panty hose, and see if you get big chunks of anything, i'll keep my fingers crossed that its only bearings, and not the gears.

RaisedK5

"Of all the things I've lost, I think I miss my mind the most!"

 

[CaptCrunch]

You said it... rear is fragg'n out man

It happened on the so called gone through 12B I picked up... pinion bearing in my case. I drained it and I have metal... my R&P are fine, but got metal. It is just gonna get worse and surely frag the R&P too... although what's the point.... to do the bearings you need to reset the R&P settings anyways so the cost the gears is pretty minimal compared to that. Does an extra 150 mixed w/ the 800+ costs of bearings and labor really hurt all that much more?

-Mikey
1987 Chevy K5 Blazer- 350 TBI
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