[GBogner]

I have a 1974 CJ5, and have a noise coming from the drive train.
My son was in an accident last week and was hit at the left rear wheel. The impact flattened the tire, bent the wheel, broke the spring and shock. We replace at the damaged parts and now have a hard to describe noise that sound like it’s coming from the transmission, but I don’t think so. The replacement springs are heaver duty springs and have lifted the rear end about 2 inches. The noise only seems to happen when the vehicle is freewheeling. I tried a lot of different scenarios to trouble shoot the problem and what I found was that costing with the transmission and transfer in neutral, the noise is constant; otherwise it’s only there at costing speeds above 30 miles and hour and goes away at about 20.

Any ides? Could the increase angel of the drive shaft be the problem?

[thenubsterman]

so it does it when your moving. could possible you have a bent axle which is causing this problem but when your under torque something shifts and it doesn't make thenoise. I guess i would try and take the rear drive shaft out and pull yourself in 4 wheel and see if it makes noise constant then, since the rear end won't be under torque

[thenubsterman]

because sorry forgot to add this. I've had rear ends go and it sounds like its the trans/transferr case but actually the driveshaft transfers the sound up to underneath you hope this helps you

[GBogner]

That’s not a bad idea!!!!!
I did raise the jeep and drove the wheels but couldn’t tell if the axel is bent; the spinning wheels looked normal.
I do have a small amount of play in the u-joints but didn’t want to start replacing parts to solve the problem. By doing what you suggest, and if the noise goes away, at least I could eliminate the transmission and transfer.

[GBogner]

Drive shaft off, no noise. I'm going to replace the u-joints and if the noise returns upon driving, I'll go for the axel and wheel bearing.
Thanks for your help!

[GBogner]

So, while I had the rear drive shaft off and found that the noise went away, I decide that for the normal cost it would be a good idea to replace the u-joints. After I replaced the dive shaft, I took it out for a test run and still had the noise. Pulled the left axel and had it check; not bent and the bearing is good. Pulled the differential cover and inspected the gears and found them to be in good shape. When turning the axel on either side of the jeep the gears are very load as the mesh together. I can’t see, but I suspect that the impact from the collision might have compressed the gear assembly a little.

Don’t know if I should disassemble the rear end and put it back together or leave it alone and see if the problem goes away; that is things loosen up by them selves and eliminates the problem after driven.

Any ideas or suggestion would be greatly appreciated!!!