Is my TH350 screwed

Repair Help Forum
1

I bought this car a while ago, a 1977 Chevy Nova, and I’ve noticed some troubling noises. There’s a whine that occurs between 40 and 80 mph, and when I take my foot off the gas from high speeds, it makes a very loud rumbling sound. I pulled the driveshaft and replaced all the U-joints, but the issue persists. When I pulled it again today, I noticed that my output shaft was loose—not centered—and it had some play in one direction. It was flopping around in there. I also found that a spline was missing from my yoke end. I’ll attach a video for reference. Does my transmission need a full rebuild, or is there a bushing or bearing in there that I could replace from the tail shaft end? I’m not the best with auto transmissions, so any advice would be appreciated.

2

That sounds pretty rough. Have you checked the fluid level? Sometimes low fluid can cause similar issues.

3

Hollis said:
That sounds pretty rough. Have you checked the fluid level? Sometimes low fluid can cause similar issues.

I haven’t checked the fluid level yet. I’ll look into that and see if it makes a difference.

4

It sounds like you might have a problem with the tail shaft bushing or possibly the output shaft itself. If it’s loose and there’s play, it could definitely lead to bigger issues.

5

Hartley said:
It sounds like you might have a problem with the tail shaft bushing or possibly the output shaft itself. If it’s loose and there’s play, it could definitely lead to bigger issues.

Do you think I could just replace the bushing without a full rebuild?

6

@Thyme
Yes, it’s possible to replace the tail shaft bushing without a full rebuild. However, if the output shaft is damaged, you might need to consider more extensive repairs.

7

I’d recommend pulling the tail shaft and inspecting the bushing and the output shaft closely. If you see any significant wear, it might be time for a rebuild.

8

Teo said:
I’d recommend pulling the tail shaft and inspecting the bushing and the output shaft closely. If you see any significant wear, it might be time for a rebuild.

Thanks for the advice. I’ll check those parts carefully and decide from there.

9

Make sure to check the yoke as well since it could be part of the problem if it’s not fitting properly anymore.

10

Gale said:
Make sure to check the yoke as well since it could be part of the problem if it’s not fitting properly anymore.

Good point. I’ll inspect the yoke closely when I have it apart.

11

If you’re not comfortable doing it yourself, it might be worth taking it to a shop. They could give you a better idea of what’s going on.