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Elusive grinding noise??????

I Have a 1986 Chevy K10 4 wheel drive ( 305ci, 700r4 tranny, np208 transfer case), the truck has a very very loud grinding noise. Like something is stripped or something. So i took to very reputable shop and he has checked yoke on rear end, yoke on transfer case, i had him to go ahead and bust apart the transfer case and the gears look fine nothing appears to be wore. so we pulled tranny and took it appart other than a second gear band nothing to speak of very little wear on clutches but there was a lot of metal shavings on magnet in pan. (could it be torque converter) or something else im not thinking of, i am at a loss. As loud as the noise was you would think it would be the part laying under the truck LOL but as of yet we cant find it. So any help you can give would be greatly appreciated

Reply to
needsacoolname
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Limited slip differential?

Reply to
RayV

Reply to
Ironlizard

needsacoolname wrote: Im sorry didnt think to post that info, it makes the noise in all transfer gears (2HI 4HI and 4LO) none worse than others that i can tell the noise is so bad its hard to distiguish but only under load. you can very easily give it gas and it sounds perfect but if you take off what i would call normal ( nothing eratic) it sounds like it is coming appart. It is so bad we put it on a platform lift and the lift has the small ramps at end to get on i did not think i was going to get it on the lift with out a running start. And yes it is limited slip differential (the inspection plates have done been removed and checked clearances and all everything is fine).

Reply to
needsacoolname

You said they had the t/case apart? What you are describing sounds exactly like a broken snap ring on the rear output shaft of the t/case. It's the snap ring that holds the output shaft in place at the large rear ball bearing. It's very common for this snap ring to break, then the rear output shaft begins to move around and comes out of engagment with planetary gear set at the front of the t/case.

Maybe they just didn't notice the snap ring was missing?

Ian

Reply to
shiden_kai

Thanks Ian but i also looked and i remember the part you are speaking of and it was fine, we completely disassembled transfer case, checked all gears, forks, snap rings, sincros, everything and to be quite honest it looked new on inside outside was rough and had a leak but inside was differant story. but thaqnk you for post and im still looking for help still not fixed and still at shop.

Reply to
needsacoolname

A short in the starter circuit? See if the flywheel teeth look beat up.

Reply to
Paul Hovnanian P.E.
[...]

We went hunting a noise similar to what you described at our shop a little while back. Almost sounded like it was coming from the back of the engine. Pulled out and tore down the transmission and everything. Finally found a broken ring gear in the drive axle. This was a class 8 truck, so it was actually the first drive axle. I didn't see you say that you've had the rear end apart.

Reply to
B.B.

Thanks guys i really appreciate the help, but yes i pulled the inspection plate off front and rear end, they where leaking so no harm no foul but there was no evidence of anything wrong there, in either. and not the ring gear on flywheel transmission is out and teeth are fine, a friend of mine suggested a bad torque converter and that would explain the metal in transmission for no apparent reason, but my question is this .......what does a bad torque converter sound or act like i havent a clue?

Reply to
needsacoolname

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