whump in rearend when letting out clutch on right hand turns. What is it??
 

Hey fella's...

SO.. here lately, I've developed this "whump" sound and what feels like a little slack that gets taken up and makes the truck jerk just slightly. This happens almost always when I'm going around a right hand slow turn (like turning a corner from one street to another) and let the clutch out after downshifting. Sounds and feels like it's coming from the rear end.

a little over a year ago, I pulled the chunk to rebuild the LS.... I had gotten the wrong kit (thanks ebay), so I hust stacked it back up and re-installed. At that time, the metal plates were pretty worn.... so I'm guessing that what's going on is that the LS is REALLY REALLY worn and slipping on turns? Or maybe it's worse... I dunno... what do you guys think?

I'm SUPPOSING that the u-joint, pinion, ring, and axle splines (as well as axles) are all okay... and that there's just something going on with the LS...

thoughts, comments, help is appreciated as always!
Andy

Also, this is it from when it was out last year... can someone identify as a trac-lok or a power-lok? I'm thinking TL...

Sounds like you covered the most obvious with the U-Joints, other thing you may check that's easy is the rear wheel bearings. See if you have any play in the wheels are if the center hub is warm after a drive. That whole drive train is always the first thing I check, including the carrier bearing.

OOOOOOHHHHH Carrier bearing!!! that's a good call. Didn't even think about that one. I've got a rear pinion seal that I need to put in anyway.

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Hey, I found a trac-lok for sale for a ford Dana 80, 35 spline, 4.10 carrier. That's exactly what I need except for the ford part... Will it fit???? I guess the worry would be the ring gear bolts.

maby back lash adjustment from the pinion and ring gear. they make a shim kit that you can get the back lash right on.

Would backlash change over time? That's interesting, when I tear into it, I'll check that.

One or two broken teeth will do that, too....

wear on the teeth and bearings will change back lash for sure

I am having the same Clunk as well I was also thinking the LS diff but dunno for sure havent gotten into it yet. :pca1:

i would pull the pan and check it out before something breaks.

have had the leaf spring block nipple break off causing problems like that

When you took it out the first time,you should have taken a note of the back lash.then went you put it back in it should be the same if not it will wear a different pattern in the gears and pooof noise over a year.The rebuild kit for the LSD is about 80.00 bucks,Im taking this is for a Dana 70.Just my 2 cent but if it is whine at u rebuild the whole rear.If u are strapped for money rebuid the LSD and get new gears,seals, bearings.

I've done a little more narrowing down of when this happens:

1. Only in off-camber RT hand turn.
2. Only when clutch is depressed before (or during) the turn. If I enter the turn, and lug out of it, it doesn’t happen.
3. In deep pack snow, if I just let the clutch out and let the idle carry it forward in a straight line, the whole truck will buck and jump pretty violently. This does NOT happen on just DRY pavement

Does that change any opinions of what the problem is? There is no whine/howl from the rear-end.