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flyingtim01 · 10-22-2012, 10:17 AM

Little update, thought nothing conclusive.

Saturday morning I changed the U joints in the rear driveshaft. Took it out for a spin, and I had the exact same condition as I did previously. Made it to the dump and back with no issue, however.

Sunday morning I woke up and realized that of all the work I've done to this truck, I've never changed the transmission and transfer case fluid. I checked Sunday, and both of them did indeed have fluid in them (the speedo cable leaks from where it contacted the exhaust pipe once upon a time) but I wanted to see what it looked like. Drained the t-case, and the fluid looked pretty normal, if a bit low. Drained the transmission, and it was rather milky. Don't know if that was just condensation or if water had actually gotten into the tranny, but it was time for it to go, anyway. A quick visual inspection through the shifter tower didn't turn up and pitting or any other signs of water, so maybe just condensation. Filled them both up with fresh gear oil, and took it back out on the road. It was much quieter, though the pessimist in me may have felt a shade of the same growling. I didn't adjust the exhaust at all, next on the list are the wheel bearings. On the highway this morning I could hear this squalling noise right at 60mph. It was hard to say if it was a wheel bearing or just wind noise, but I know that one rear bearing is at least out of adjustment, and at worst it's shot, so I might as well do all four corners.

10-22-2012, 10:17 AM	#11
flyingtim01 Registered User Join Date: Apr 2011 Location: Clinton, CT Posts: 101	Re: '71 K20 Growling/Grinding noise Little update, thought nothing conclusive. Saturday morning I changed the U joints in the rear driveshaft. Took it out for a spin, and I had the exact same condition as I did previously. Made it to the dump and back with no issue, however. Sunday morning I woke up and realized that of all the work I've done to this truck, I've never changed the transmission and transfer case fluid. I checked Sunday, and both of them did indeed have fluid in them (the speedo cable leaks from where it contacted the exhaust pipe once upon a time) but I wanted to see what it looked like. Drained the t-case, and the fluid looked pretty normal, if a bit low. Drained the transmission, and it was rather milky. Don't know if that was just condensation or if water had actually gotten into the tranny, but it was time for it to go, anyway. A quick visual inspection through the shifter tower didn't turn up and pitting or any other signs of water, so maybe just condensation. Filled them both up with fresh gear oil, and took it back out on the road. It was much quieter, though the pessimist in me may have felt a shade of the same growling. I didn't adjust the exhaust at all, next on the list are the wheel bearings. On the highway this morning I could hear this squalling noise right at 60mph. It was hard to say if it was a wheel bearing or just wind noise, but I know that one rear bearing is at least out of adjustment, and at worst it's shot, so I might as well do all four corners.