Im going to be putting a TH-400 in my 67 firebird 400, but I cant deicide if I want to put in a brand new TCI Th-400 or have the one I have now rebuilt. Whats involved in rebuilding a 40 year old TH400? What would it cost to have someone rebuild it for me? Although im a do-it-yourselfer ive heard that rebiulding these things is like doing brain surgery. Thanks.

I think a TCI unit is rebuilt too. Nobody can afford the tooling for a brand-new box except OEMs. Have you priced them? What are they going for these days?

Just have yours rebuilt. The TCI unit is also rebuilt.

You can get a 400 rebuilt by most any transmission shop and some can do even a performance build for you. I had the last one built by a friend of mine who was a retired trans builder for a $100 for the labor and I bought all the soft parts for it for for another $150

Don't try it yourself unless you have allot of patience!

Th400's are my favorite trans'. As a matter of fact I just redid one yesterday. I go get crazy when I build mine. With a new converter, you can easily spend over $1000 in parts alone. I did a "mild" build on this one and spent around $800 in parts plus a new $200 shifter. It adds up quick. Setting up the clutch assemblies is the tricky part. With some of the mods I do , you only get one shot at it before your buying parts. The TCI's are a good investment because they have alot of the hard to find expensive parts in them already. ie: Hardened input shaft, steel drum already turned down for a 32 element sprag, case saver, early style pump with the two extra bolts. This may not seem like alot, but the things go along way to make the trans hold up. Some stock transmissions came with this stuff, but alot of them didn't. If your drum isn't turned down, your stuck with a 9 element sprag. It is very time consuming and technical to do this, but once you learn it, it seems easy. Two tools are a must for this, a dial indicator, and calipers. Dont even take the drums out without those. Dry lash in the clutch assemblies is critical. The more lash you have the harder the shift, the shorter the life. If you set the assemblies up tighter, it'll last longer, but shift slower and softer. If you set them up too tight, you'll burn up the assemblies super quick. Then there's the whole reprogramming kit thing to consider. (make it shift harder with the valve body rather than the clutch assemblies) I guess all this sounds complicated, but it really isn't.

I hope its not TOO complicated cuz Im planning on rebuilding my TH350 very soon. A couple months ago I ordered a B&M kit from Summit for a couple C-notes but have been too busy since then to do it. Is that a decent rebuild kit? Transmissions are one thing Ive never torn into, never even had a desire to...will I survive it? :D

I've only rebuilt Powerglides. Not many parts to one of them.
It was pretty easy, but I did need a tool I didn't own at the time and it caused a problem. I ended up needing a tranny shop to tell me what I did wrong.
I was major bummed. And the kitchen table was ruined.
;)

They have step by step books on how to tear down a transmission and put it back together. Th350's are way more complicated than Th400's in my opinion, but that may be just me. The problem you'll run into with the Th350 is you won't be able to pull the planitary gears out. It's been a LOOOONG time since anyone asked me to do a 350. I don't remember how with out looking at it. If the trans works ok and you just want to replace the clutch assemblies, you won't even have to worry about it. The only thing to replace back there are bearings and bushings. Oh wait, maybe the direct clutch assembly (third gear) is back there. ......Like I said It's been a while and I'd have to see it again.
Buy the book.

BTW, B&M is a very good kit if you got the master kit with all the goodies in it. If you spent 2 bills on it, that should be the good kit. I buy all my trans stuff almost exclusively from B&M.

CDjr, your two hours from me. If you get stuck, let me know.

Thanky earthquake, I may take ya up on that :beers: I have Ron Sessions book on it and all the tools to do it with, as best I can tell. I also got a 20-ton press, cuz the guy who persuaded me into rebuilding it told me itd come in handy for pressing stuff in and out lol.

I know of an auto shop instructor that has rebuilt some transmissions. He says its no more complex than rebuilding a carburetor. He thinks if you can rebuild a carb, you can rebuild a tranny. I've rebuilt some carbs but never a tranny. I have a power-glide I am probably going to try to rebuild sometime in the future though, it slips pretty bad. But for now, I'm just replacing it with a TKO.

I know of an auto shop instructor that has rebuilt some transmissions. He says its no more complex than rebuilding a carburetor. He thinks if you can rebuild a carb, you can rebuild a tranny. I've rebuilt some carbs but never a tranny. I have a power-glide I am probably going to try to rebuild sometime in the future though, it slips pretty bad. But for now, I'm just replacing it with a TKO.

That's a pretty good association. Like I said, it may seem overwhelming at fist, but once you learn it, piece of cake! (just like a carb) Hmmmm, 327, now that's a good fix for a slipping trans!:thumbsup: