Posted by TomT on October 30, 01 at 22:29:07:
In Reply to: bad luck. this is probably the case for me... posted by Lou on October 30, 01 at 20:55:06:
A couple of things...
1) This argument that the tranny will take a crap after the rear diff locking up doesn't really fly with me. Has anyone ever locked up the rear brakes (pre-ABS)? Or are you guys referring to a sharp snap in the driveline.
2) This sounds a lot like someone who didn't service the crappy 1/2 ton Gov-lock (like me). I never added the friction modifier to my 1/2 ton diff. After heating up on the hiway, the thing locked and released after turning around the corner. Also, the inside tire locked up as well to add a bit more drama to the deal. After the spider gears exploded, I replaced the Gov-lock with an Eaton unit. If I had it to do all over again, I would have put some sort of locker in the pumpkin as the lousy articulation spins the light side with the limited slip.
I can't say much about the tranny. The 4L60E is kind of weak. I've got 130K miles on mine, but the 1st to 2nd gear shift when it is hot under full throttle is very sloppy, so I have to baby it.
BTW, when I bought my 3/4T '01 Burb 4X4, the differential service was one of the first questions out o' my mouth.
It seems as though GM has somehow addressed it now.
Good luck and I welcome opposing opinions,
Tom
: I was traveling at 60MPH on the highway, and took
: an off ramp. Stopped at the end of the off ramp.
: As I was turning left onto the back road, at about
: 15MPH...CRUNCH! UnGodly grinding from under the truck, but IT KEPT MOVING FORWARD...and I COASTED (at 15MPH)
: to the shoulder. Then it sorta lurched to a stop, as
: if I was tapping the brakes. I put it in park and
: looked under the truck and saw the 2 big holes in
: the differential cover.
: Well, after the rear was replaced and the mechanic
: went for a test drive, he CLAIMS the tranny is toasted.
: Erratic shifting, then stuck in 1st gear. HE thinks
: that the TRANS wiped out the REAR. I don't see how
: that's possible. He said "well, if it suddendly
: downshifted from 4th to 1st at 60 MPH, it would stress
: everything out."
: But it DIDN'T DO THAT. It all performed perfectly
: until I stopped, and made that left turn. Now: My
: posi hasn't worked right in a while (slipped/no posi
: action)...I wonder if something was broken, and
: maybe this left turn finally freed up something in the
: actual differential or posi unit which ended up in the
: gears. I'm sure I'll never know. But how many times
: does a rear blow up at 15 MPH?
: Lou