Ok I'm pulling my hair out a bit here. I got new (higher) gears from Terrain Tamer for my transfer case. The kit includes 3 gears: input, high idler, and high output. I also got all new bearings and seals from Akella.
So I got all the gears and bearings set up on the shafts and new races and seals in place in the housing, and bolted it all together. Seemed tight... Figured theres a lot of stuff to spin and new seals so maybe that's it. Test drove around the block, very noisy.
Took driveshafts off, flanges are still too tight to turn by hand. Took the rear extension housing off and (transmission in neutral) could easily spin the front drive flange. The rear extension is what pushes on the idler bearing shim... So that must be what is tight. (Output shaft shim has its own plate independent of the rear housing.)
Ok, follow FSM procedure to measure with callipers, straight edge + feeler gauge, etc. Calculated that I need a shim approximately 0.04 inches thinner. Ok, it's just a piece of metal this shouldn't be too hard..... bench sander, callipers, etc. got it thinned down to the right thickness. The thickness is even within 1 thou which I figure should be good enough.
Back together, test drive, still a little noise but much less. No noise at all when coasting. Minimal noise under deceleration... So I'm thinking:
1) Bearings are still too tight, and I need to make the shim even thinner.
2) Bearings are shot from being run too tight... they will be noisy until I replace them.
3) Noise is from the new gears, and it was magnified through the case by tight bearings. Now that they are looser, the noise is quieter, but no amount of bearing adjustment will totally eliminate the noise.
I really hope the answer is not #3 because these gears were very expensive! #2 would be a real drag too, cause I'd have to take the whole t-case out again. But I'm worried with #1 if I keep making the shim thinner and thinner... running bearings too loose can't be good for them either?
What do the gurus think?
So I got all the gears and bearings set up on the shafts and new races and seals in place in the housing, and bolted it all together. Seemed tight... Figured theres a lot of stuff to spin and new seals so maybe that's it. Test drove around the block, very noisy.
Took driveshafts off, flanges are still too tight to turn by hand. Took the rear extension housing off and (transmission in neutral) could easily spin the front drive flange. The rear extension is what pushes on the idler bearing shim... So that must be what is tight. (Output shaft shim has its own plate independent of the rear housing.)
Ok, follow FSM procedure to measure with callipers, straight edge + feeler gauge, etc. Calculated that I need a shim approximately 0.04 inches thinner. Ok, it's just a piece of metal this shouldn't be too hard..... bench sander, callipers, etc. got it thinned down to the right thickness. The thickness is even within 1 thou which I figure should be good enough.
Back together, test drive, still a little noise but much less. No noise at all when coasting. Minimal noise under deceleration... So I'm thinking:
1) Bearings are still too tight, and I need to make the shim even thinner.
2) Bearings are shot from being run too tight... they will be noisy until I replace them.
3) Noise is from the new gears, and it was magnified through the case by tight bearings. Now that they are looser, the noise is quieter, but no amount of bearing adjustment will totally eliminate the noise.
I really hope the answer is not #3 because these gears were very expensive! #2 would be a real drag too, cause I'd have to take the whole t-case out again. But I'm worried with #1 if I keep making the shim thinner and thinner... running bearings too loose can't be good for them either?
What do the gurus think?
