Broken yoke and bent driveshaft

JWAYNE88

MEMBER
2000 GMC SIERRA
6.1L
V8
2WD
AUTOMATIC
250,000 MILES

I'm working on a truck for my boss, I pour concrete by trade, but am one of those jack of all's, so a U-joint replacement I assumed, ended up being a broken yoke with substantial rust and a bent driveshaft and damaged end where U-joint had to be cut out.
It looks like it had suffered this damage a while back in its history and instead of replacing the yoke and bent driveshaft, they just stuck it back in and hoped for the best.
I could be wrong but the damage looks aged and a few months back the driveshaft hit the highway and it has sat in the grass every since.
I have a new yoke and driveshaft to install, he said the transmission runs hot which could be a symptom of driving with a damaged drive train.
How can I find out before I do all this work if to much damage was done to make fixing it worth more time and money?

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

Just so I understand the current state. Is the vehicle still able to drive or do you have the old drive shaft removed?

As for the transmission running hot, it could be related to the damaged drive-train but it all depends on the extend of the damage. If it was just the drive shaft and yoke, then I doubt it is causing the transmission to get hot. This is most likely due to a transmission cooler or greater transmission issue.

I would suggest to go ahead and fix what you know is broken and then you will have to re-evaluate the overheat issue.

If I had to put money on it, I would say you have other issues. However, it could be just as simple as the fluid is burnt. If so this causes the pump to work harder and clutches to slip, which creates heat raise the overall trans temp.

Let me know what you find after you fix what you know is bad and we can go from there. If it were my truck, I would take this approach because even if you dump it after because you don't want to do the trans work, you won't get what it is worth with a bent drive shaft and yoke issue. Point being, just doing these couple things won't put you so far in that it is too late to cut your losses.

Thanks