TH350 goes forward in reverse..

[Christian Nelson]

Hey y'all, I rebuilt my dad's TH350 on his square, and it was working great for 2 years.

Then, this summer, he went to back it up, and it wouldn't go anywhere, but eventually it moved forward, but acted like there was binding going on.

All gears but park move it forward.

Does this sound like something is stuck in the valve body to y'all, or does it sound like one of the sprags has let go?

I'm hoping I don't have to drop the tranny.

We checked the linkage, and it shifts fine through all the gears, park through low 1.

Thanks..

 

[JoeR Jr]

Hey y'all, I rebuilt my dad's TH350 on his square, and it was working great for 2 years.

Then, this summer, he went to back it up, and it wouldn't go anywhere, but eventually it moved forward, but acted like there was binding going on.

All gears but park move it forward.

Does this sound like something is stuck in the valve body to y'all, or does it sound like one of the sprags has let go?

I'm hoping I don't have to drop the tranny.

We checked the linkage, and it shifts fine through all the gears, park through low 1.

Thanks..

A couple of things would have to happen for the truck to do this.
1) The Low/Rev clutch pack has to be slipping
2) Some other clutch must be applying in addition to the direct Clutch to get forward drive.

It's possible it was caused by a valve body problem, but you're pulling it regardless. It's probably going to have to come apart again.

Joe

 

[Christian Nelson]

I really have a hard time believing my dad smoked the direct clutches. Not with that tired old 350, and the way he drives..

That's why I'm thinking something is up with the valve body. Either way, I gotta drop the pan. I'll let y'all know what I find.

 

[Christian Nelson]

Looks like the clip fell off the gear selector shaft, allowing the rooster comb nut to back off, and the S clip to fall out, so no matter which gear you shifted to, it was in drive. The rooster comb was loose, but still engaging, and the par pawl was still locking in place, but other than that, it was always in drive. We tightened everything up, put the pan back on and filled it with oil, and it now has reverse.

Tranny guys need to work on always assuming everything needs to be torn down and rebuilt.

All the experts I asked, said the forward clutches were burned up, and welded together. I knew that wasn't possible the way my dad drives.. Every example I saw of that happening was on the drag strip, or people doing neutral drops. My dad babies his truck!

ONly issue was trying to find the s clip, it was hiding behind the filter. Fluid looks good after two years away from the rebuild No material at all to speak of in the pan. Glad we don't have to drop the tranny, for sure!!

Now, I can get back to my $&*& Saturn head replacement! Snapped cam bearing bolt, and spent 5 hours getting that stupid thing out. Ended up shoving the MIG gun right onto the hole, and squeezing the trigger a few times, and building up a stud to turn the busted piece out. Shoulda done that to begin with..

 

[JoeR Jr]

Glad you got it figured out!
Joe

 

[LAsquarebody]

Looks like the clip fell off the gear selector shaft, allowing the rooster comb nut to back off, and the S clip to fall out, so no matter which gear you shifted to, it was in drive. The rooster comb was loose, but still engaging, and the par pawl was still locking in place, but other than that, it was always in drive. We tightened everything up, put the pan back on and filled it with oil, and it now has reverse.

Tranny guys need to work on always assuming everything needs to be torn down and rebuilt.

All the experts I asked, said the forward clutches were burned up, and welded together. I knew that wasn't possible the way my dad drives.. Every example I saw of that happening was on the drag strip, or people doing neutral drops. My dad babies his truck!

ONly issue was trying to find the s clip, it was hiding behind the filter. Fluid looks good after two years away from the rebuild No material at all to speak of in the pan. Glad we don't have to drop the tranny, for sure!!

Now, I can get back to my $&*& Saturn head replacement! Snapped cam bearing bolt, and spent 5 hours getting that stupid thing out. Ended up shoving the MIG gun right onto the hole, and squeezing the trigger a few times, and building up a stud to turn the busted piece out. Shoulda done that to begin with..

I just swapped out my engine and when I finally got it all running I dropped it into reverse and the d*** thing crawled forward. Lol. Was happy to find this post in here, mighty helpful. I personally know next to nothing about transmissions but good time as any to learn I guess.

I am going to start googling all the parts you listed above to become familiar with the job before I pull the pan and spend the afternoon on the creeper tomorrow but if you happen to see this and have any additional advice I would appreciate anything.

Thanks for all the info. Was about to open my phone and start looking for a new trans haha.

 

[mshawn]

Looks like the clip fell off the gear selector shaft, allowing the rooster comb nut to back off, and the S clip to fall out, so no matter which gear you shifted to, it was in drive. The rooster comb was loose, but still engaging, and the par pawl was still locking in place, but other than that, it was always in drive. We tightened everything up, put the pan back on and filled it with oil, and it now has reverse.

Tranny guys need to work on always assuming everything needs to be torn down and rebuilt.

All the experts I asked, said the forward clutches were burned up, and welded together. I knew that wasn't possible the way my dad drives.. Every example I saw of that happening was on the drag strip, or people doing neutral drops. My dad babies his truck!

ONly issue was trying to find the s clip, it was hiding behind the filter. Fluid looks good after two years away from the rebuild No material at all to speak of in the pan. Glad we don't have to drop the tranny, for sure!!

Now, I can get back to my $&*& Saturn head replacement! Snapped cam bearing bolt, and spent 5 hours getting that stupid thing out. Ended up shoving the MIG gun right onto the hole, and squeezing the trigger a few times, and building up a stud to turn the busted piece out. Shoulda done that to begin with..

Seems to be the most used tool for a Saturn, mig!!!! Jk I hope the head replacement gos better now!

 

[Frankenchevy]

Saturns are actually pretty good cars. I’ve seen some really high mileage ones.

 

[LAsquarebody]

What do you know? Opened the pan and found this guy pulling a cliff hanger. Thanks again to the forum for all the help. Also in case anyone else finds this post in need and has very little transmission experience Im going to post the YouTube video I found of a guy busting down a TH350 and then rebuilding it. Was super helpful for me to watch prior to getting in there and doing my first transmission job.

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