Transfer Case Chain Stretch, a myth?

IBallEngineer

New member
Does anyone have first hand experience of this happening? I know we all prefer a gear driven case, but has anyone had a chain stretch, or suffered a catastrophic failure of a chain driven case? I've seen pictures online, but they were 2nd gen, and 4th gen runners. I'm thinking a new chain in a stock case with a doubler in front would be just fine for most any trail rig. Unless of course, someone knows better.

:confused:
 
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I replaced a few excessively worn T-case Morse type chains back in the day. Including some early Toyota T-case chains. I've also replaced a few grenaded T-cases. Some were chain drive.

The chains generally don't really stretch, as in the sideplates actually elongate, unless there is some extreme strain placed on the chain. But usually other components (like the u-joints) would break first (as designed), before that happened. So-called chain-stretch is most often just the accumulated wear on the pins and side plates that effectively makes the chain longer.
 
Late '90s to '00s Chevy 2500s are notorious for having t-case chains that stretch out and eat through the case itself.

However, I've never seen nor heard of any Toyota transfer unit having this issue. Sure, they might break under heavy load, but stretch doesn't seem to be a problem.
 
As mentioned above the T-case housing for the Chevy pickup ends up getting a hole in it due to a clip that is worn against the housing set in a little grove. If it isn't caught in time then bye bye transfer case.

I have never seen such from a Toyota personally but have heard stories.
 
As mentioned above the T-case housing for the Chevy pickup ends up getting a hole in it due to a clip that is worn against the housing set in a little grove. If it isn't caught in time then bye bye transfer case.

I have never seen such from a Toyota personally but have heard stories.
Wagoneers were bad about this too.
 
I do know that fellow member Qyota on his way to Grandma's house for Turkey or Xmas Day last year and ended up in a ditch and after being able to drive out of it couldn't get the transfer case to work.

He ended up buying one from the Southwest and having a local shop install it. He was going to tear it down this summer and post his findings.
 
The Rock Lobster rig had it happen with his dual cases in Moab if I remember correctly. SteezeMcQueen was the name I think.
 
I don't think the chain is the weak point in a stock tcase. I've never heard of anyone breaking one really. The only thing I've heard of breaking is the actual case itself.

Fwiw I'm running a 4.7 crawler in front of my stock case without any issues.
 
we run a stock case with 37's and 4.56's without any issues, and he believes in the skinny pedal !!! But yes stretching the chain is possible, but not likely. Best thing to do is open it up and see what's chewed up or rubbing
 
Does anyone have first hand experience of this happening? I know we all prefer a gear driven case, but has anyone had a chain stretch...

Mine suffered (I think) some stretching last summer as i climbed i-70 west to east over the Rockies (that is Some strain pushing the engine to 4000rpm in 2nd gear at nearly 15000ft with almost 45% power loss due to altitude). Won't do that again with this T4R.

Didn't notice any new sounds until Denver. It rattled (mildly) at idle, not under power. During the winter, the rattle went away and returned even more mildly this summer. Drives ok otherwise. Some say it can't possibly be the gear case rattling at idle cuz nothing is moving inside. I say, come listen to my steth, it is Very clear the sound comes from the t-case at idle and nothing else around it. Not too worried about it. :cowboy:
 
I don't think the chain is the weak point in a stock tcase. I've never heard of anyone breaking one really. The only thing I've heard of breaking is the actual case itself.

Fwiw I'm running a 4.7 crawler in front of my stock case without any issues.

That's exactly the scenario I'm wanting to see. Are you running a gear driven box in front of the chain driven stock case? How hard do you push it?
 
The Rock Lobster rig had it happen with his dual cases in Moab if I remember correctly. SteezeMcQueen was the name I think.

I thought it was the chain but it ended up being a bearing in the crawl box.

I've been running a 4.7 geared case in front of the chain case and haven't had any issues with the stock case. I'm not easy on my stuff either.
 
I thought it was the chain but it ended up being a bearing in the crawl box.

I've been running a 4.7 geared case in front of the chain case and haven't had any issues with the stock case. I'm not easy on my stuff either.

Good news. I am trying to get one of my best friends to donate his first Gen to his son and join the modern world of 4 doors and power windows LOL. He's looking at Ol' Blue's SAS which uses a left hand drop. My friend runs dual cases in his 85 and is aFEARED of chain driven cases. This is what happens when you get over 50, you become pigheaded, obstinate, and sometimes stupid. Oh wait, we were always that way... So anyway, he loves the idea of the crawlbox, and I assured him the chain issue was not a big deal. I think I have him on the ropes now. Knowing him if he does buy it, he'll replace the chain when he adds the box anyway.

Thank you all for the input!

:keyboard:
 
That's exactly the scenario I'm wanting to see. Are you running a gear driven box in front of the chain driven stock case? How hard do you push it?

Yeah TG adapters and 4.7's. And I don't know what a bypass is in my truck, point and shoot at anything technical in the rocks
 

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