Offroad Trailblazers and Envoys

Stretched TC Chain???

Something not working right?

by KingBird » Sun Jun 26, 2016 12:03 am

I have already fixed the issue, the title is correct. I figured I'd post up though, so the rest of you know what could happen.

https://youtu.be/rRUoz0r3vog

The above video shows what I was dealing with, a loud popping noise from the front of the vehicle and the fronts were "surging" under load.

I told my wife that it was the locker engaging in the video so she wouldn't freak out since we were away from an improved road.

I keep up with my half-shafts, and other 4wd maintenance pretty often, but I switched my half-shafts out just-in-case and had the same problems. The loud popping would happen while climbing, when turning on asphalt and binding up the drive line, and when taking off from full-throttle in gravel with 4wd engaged, whether in low or high range.

It behaved normally in 2wd mode.

I put the vehicle in park with 4hi on, and crawled under the vehicle to see what was binding up. The front prop shaft had an incredible amount of slop when I tried to turn it by hand back and forth with all four tires on the ground.

Because of this, I jerked the TC. Once I split it in half, I noticed that the chain just didn't look right. I took the chain out of my 126 case and compared the two but saw no difference. All TC internals looked great,the clutches looked like they had never been used. I switched chains anyway, and threw the case back together, then reinstalled.

I no longer have any noises coming from the TC in any of the above mentioned scenarios..

How did I break it in the first place you ask? I attempted a climb in 4hi yet thought I was in 4lo. Towards the top of the climb, we heard a faint snap, the engine was turning around 3k RPM.

Be careful out there boys!
Bravada G80 3.73 converted to selectable 4wd.
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KingBird
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by Regulator1175 » Tue Jun 28, 2016 12:02 am

Kyle, check out the video. That sounds like the same noise mine was making.
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by v7guy » Tue Jun 28, 2016 4:47 am

Thomas, check this out, it was just like my experience.

Interesting a chain swap fixed it. I always guessed the clutches would be the weak point. I'd probably start seriously looking at a replacement TC. I figured I'd rock mine until it's an issue. You're the first one I've seen with this problem, congrats!
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by KingBird » Tue Jun 28, 2016 12:38 pm

I actually am looking for another 226 TC but only so I have a spare case. I'm also kicking around the idea of changing mine out with a case and appropriate adapter from an H3 "adventure" TC for that 4:1 ratio (just to see if I can). In the meantime I'm just gonna get a new chain to have on hand. Like I said, I completely dismantled mine and everything looked great so I don't think an entire new TC is a necessity.
Bravada G80 3.73 converted to selectable 4wd.
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