Driveline grind in 2nd during left turns

[Army12Valves]

I am trying to chase down a grinding vibration I get when making left turns from a dead stop in 2nd gear. It is subtle but noticeable and not in the front end, is it transmission, transfer case or rear end?



It wont do it with a trailer or heavy load in the bed, and wont do it in any gear but 2nd, and left turns from a dead stop only.



1992 W250 Getrag 360, 205, Dana 70, 348,000mi

 

[RedRamAndy]

Limited slip in the rear? Spider gears wearing out in that cluster?

 

[HHhuntitall]

... . or possibly a loose bearing in the rear hub, giving it just enough room to move and touch the backing plate or pads. Check the carrier bearing, as well. Launch torque may be making it move some?

 

[MikeW.]

Had a car do that only from a dead stop and then a turn, didn't do it if I went straight a bit and then turned. Changed out the rear end oil and the problem went away.

 

[RSchwarzli]

Dont start in 2nd gear! Problem solved!

 

[Army12Valves]

Dont start in 2nd gear! Problem solved

1st is too low, and 3rd is too high

I'm opening it up this afternoon, I'm semi afraid of what I'll find

Rear disc brakes so it isn't drum issues

 

[Army12Valves]

So I opened up the rearend to find a freshly rebuilt differential, no noticable wear or incorrect placement of anything, no excess metal, just dirty oil. So I sealed her back up and added a gallon of Valvoline 85w-140 with posi additive, The noise has vanished. Is this just temporary or a high milage gremlin that will never show its face? My only thoughts are that without pulling everything apart it could be that the pinion was drawn up with an impact gun and not properly seated or torqued, the new oil is just hiding a bad bearing. However there was no evidence of a bearing being chewed up, the posi looks nice, spiders ring and pinion, also the ring and pinion are tracking nicely, not too deep or shallow. I am confused I really want to find the source of the grind, I need to drive this truck from Columbus GA to Olympia WA in about 10 weeks.

 

[HHhuntitall]

Lack of friction modifier will make the clutches chatter in the posi. Hopefully, that's your problem, and it's now taken care of.

 

[cerberusiam]

Yep, could just have been the gear oil that was in it before. When mine would start that I would change the gear oil and add 2 bottles of the Mopar LSD modifier and it was smooth.

 

[Army12Valves]

Lack of friction modifier will make the clutches chatter in the posi. Hopefully, that's your problem, and it's now taken care of.

That is the exact idea that popped into my head today while driving it around Fort Benning. I hope you're right, it does make sense.

 

[RedRamAndy]

I thought it might be that. That's why I ask the question about a posi but never got answer. Glad you fixed it. And I do belive you fixed it. Relax and drive. I've been there before. Congrats.

 

[MikeW.]

So I opened up the rearend to find a freshly rebuilt differential, no noticable wear or incorrect placement of anything, no excess metal, just dirty oil. I am confused I really want to find the source of the grind, I need to drive this truck from Columbus GA to Olympia WA in about 10 weeks.

Mine was a 62 Chev Burb and after changing the dirty oil I drove it across country twice and around Ariz. for another year so good luck and hope this is the fix.