Transfer case issues: rotten noises and won't stay in 4low (1 Viewer)

[HausePhoto]

Truck is a 1989 4runner, 22re, automatic.
Lately, when accelerating quickly from a dead stop, I've been hearing an unpleasant groaning/grinding/rumbling sound from the vicinity of the transfer case, and when I put it in 4L it makes the same sound (but worse), and keeps popping out of 4L.

I changed the fluid (auto trucks use Dexron II in the transfer case), but the old fluid looked fine, and the noise/popping out of 4L continued exactly the same.

Thoughts? Advice? I've searched the forums, but haven't really run across anything similar.

Thanks all.

 

[ferg]

Has it been worked on before, like by a prior owner? Possible failed poppet spring. When you changed the fluid was there any chunks or junk in it?

 

[HausePhoto]

Has it been worked on before, like by a prior owner? Possible failed poppet spring. When you changed the fluid was there any chunks or junk in it?

I have no idea if it's been worked on before. How intensive would a rebuild/parts replacement be, in terms of specialty tools, etc.

The fluid looked fine to me. No sludge or chunks, or metal shavings to speak of.

 

[ferg]

First clue to having been cracked open is RTV instead of proper gaskets. Get a tech manual for the truck. Read it. Then determine if you are capable of such work. Some folks are, some aren't.

Crawl underneath and grab the drive shafts and yank them around and check for play or excessive movement.

Have a friend or knowledgeable Toyota guru help. Sometimes even Jeep guys know stuff and can be of use.

 

[HausePhoto]

Word. Thankses.