I just broke the TH 350 in my 69. I guess the new ZZ430 was too much for it. It was working fine, shifting nice and hard but then went BANG in high gear. :mad:
At least it broke while I was on it hard. :D

So it's out of the car and I'm going to tear into it. I've never done this so for those that have, which manual would you suggest? I have the GM ovehaul manual but looking for some other books that may have more performance minded info.

I'm also toying with converting it to a 700R or 200R or maybe a 5/6 speed manual, but still want to tear into the TH350 to see what broke.

Thanks
joe

I have one called "Turbo Hydra-Matic 350 Handbook" by Ron Sessions. If you can't find one locally, shoot me an e-mail.

That may be the same book I saw at my local Barnes and Noble book store. You might check there. Also see if THM350 turns up anything on Amazon.com. IMHO one overhaul manual is as good as the next (generally speaking), but the book-store manuals tend to reveal more of the tricks which is what I think you are looking for.

You can always get the video too, here is a link to JC Whitney, they have the TH350 video as well as manuals

http://www.jcwhitney.com/autoparts/ProductDisplay/c-10101/s-10101/p-169929/mediaCode-ZX/appId-399908

a Trany man told me once. All you need to do your own TH 350 rebuild is a book and a very clean place to work on it. Also a place to clean up all the parts. And then he said make sure it's clean and were your working is clean. Said it was pretty simple afer that. I have never been into one yet though.

Joe

You broke the intermediate sprag outside race. Its located right behind the oil pump. You'll see it when the pump is pulled.

Thanks for the info guys. I got the Ron Seesion book. It's pretty informative.

When I took it apart, the forward clutch drum had cracked where the input shaft is pressed onto the splines. Everything else is in perfect shape. Even still has the printing on the clutches. It looks like maybe the shaft wasn't pressed in correctly and maybe weakened the drum? :(

Or do I have too much torque? I recently put a ZZ430 clone crate engine in; it has 435 hp and 435 tq. Maybe I drive too hard.. :D

The trans had been "rebuilt and beefed up" before I bought the car 1 1/2 years ago. It shifts good and hard. I don't know what kind of shift kit it has, but there was only one check ball in the valve body.

I'll find a donor trans and get the input shaft and drum and put it back together. If it breaks again, I guess an upgrade is in order. graemlins/thumbsup.gif

Thanks again
joe

While you have it apart, you might as well visit your local trans shop and buy the drum/shaft and re-install the trans. It would be alot quicker.

You're probably correct it suggesting the input shaft was installed incorrectly. They may have forgotten to support the drum properly when pressing in the shaft.

I had a TH350 trans for two years. I had a B&M kit in it and 1-2 shaft was like a 12 ga. shotgun, always busted the outer race. Lost second gear, but, always had first gear to move the car.

Oh, reminds me, when assembling the drum package and the sprag, use a rubber band to hold rollers in place on the inner hub. Install the outer drum, then cut off the rubber band. WA-LA!

Thanks for the advise. I was thinking of just getting the parts from a donor tranny. If it's not cracked it should work OK (I think). Are you suggesting I buy new parts?

Merry Christmas.

joe

No, if you have a donor trans and the part passes the "ring test" for no cracks, then go for it. I don't think you'll find new hard parts, maybe at the dealer.

Ring test = hold part up with a wire at one place, not touching any other surface on the part and tap with a hammer. Listen for a "tuning fork", ie., ringing sound. If not a "thud," then no cracks.

And my mistake:
Oh, reminds me, when assembling the drum package and the sprag, use a rubber band to hold rollers in place on the inner hub. Install the outer drum, then cut off the rubber band. WA-LA! Should read: When assembling the intermediate sprag assembly, wrap a rubber band about the inner race. Place the rollers under the rubber band. Slide on the outer race, cut the rubber band and remove it....WA-LA! Replace the plate and snap ring. Assemble the trans.

Thanks for the help!
I'm off to Pick-n-Pull today. I hadn't thought about the "ring test". That makes pefect sense.

And so far it does seem pretty simple to work on. I just have a bunch of pieces in small containers.

Merry Christmas

joe