jgage
Junior Member
- Joined
- May 21, 2018
- Posts
- 9
- Reaction score
- 4
- Location
- Mountain Rest, South Carolina
- First Name
- John
- Truck Year
- 1980
- Truck Model
- c10
- Engine Size
- 350
So I went and looked at an 86 GMC Sierra short bed today that I was hoping to (and might still) buy. It would be my first square body and exactly what I’ve been wanting for so long. In the ad the kid said it needed a ujoint and was otherwise a good runner. Well he was half right. The 350 ran great. The trans seemed to shift really well. He said it was a TH400 but I’m no expert yet. The problem was it’s not a u joint, he said his “buddy” put a new driveshaft in it for him and said that it had a bad u joint. Well the ujoint seem fine driveshaft doesn’t slip in to the back of the transmission very far at all. You can wiggle the driveshaft and see that it’s moving in the back of the transmission. It is dripping fluid just a little as well, I’m assuming because the shaft isn’t far enough in or the vibration has ruined a seal at the rear of the transmission. If you are giving the truck any throttle at all it runs smooth as butter. When you let off throttle it vibrates BAD. I’m actually surprised that with it just barely slipped in to the transmission that it doesn’t sling it out because it vibrates so much. If I get a driveshaft for this thing what are the odds that it’s done damage I. The back of the transmission? That’s my concern, I can buy a driveshaft but if it’s messed anything up inside it my wife is gonna be pissed when I sink more money in it. Any help or pointers would be great. It was so hard to walk away without this truck because I wanted it so bad but dang that driveshaft concerns me. Thank you in advance.