on my 87 4wd, when the engine rpms hit about 2500-3000, the transmission makes a kind of rattle-y, ring-y, ping-y noise. but it goes away when i put it in 4wd hi/lo. it does it when i push the clutch in and rev. can't remember if it does it just in neutral, i will have to check. the transmission is full of oil, but i dont know how old it is. any ideas? thanks!

You sure it's not an exhaust rattle? Like a loose heat sheild or something?

 

GD

i thought about that too, but the fact that it goes away the moment i put it in 4wd makes me think it isnt something loose.

 

it has done it since i got it running last spring. i had a couple of CV boots on the front go, and when i replaced those, i didnt notice anything being loose, but i will double check next time i get a chance.

The exhaust is hard-bolted to the transmission. Putting it in 4WD could simply be reducing the vibration or masking a bad u-joint in the rear drive line.

 

GD

that makes sense i will give it a look this weekend hopefully. that would be awesome if it was just loose exhaust. thanks!