Has anybody here rebuilt their own transmission?

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Has anybody here rebuilt their own transmission? I know Bill did the one in his hot air car. He said it wasn’t too hard. It seems transmissions have always been like “black magic” in the automotive world. I’ve always been told basically that you know how they work. But you don’t mess with them because if you screw one up it could blow your foot off. And I like having a pair of feet. I’ve seen several in different states of disassemble and reassemble. It doesn’t look that hard as long as you assemble everything and shim correctly. But then again they do it on a regular basis. Just like running a Bridgeport Mill. I can do it effortlessly and make it look easy. But I had a long learning curve to get to that point. This is the only thing on my car that I haven’t had my hands into. Other than putting the reverse manual valve body in. I know that Turbo 350s can live up to 1,000-1,200 HP. Just wondering what they do to make them live and how hard mechanically it is to do it. I know that they are basically a big jigsaw puzzle and you can’t use a BFH to put them together!!! And cleanliness is next to godliness. I am just kicking around the idea of trying to do it myself. Any ideas???

[Madboost]

Talk with Iceberg, I think he has done a th350 but it was years ago.

Bill any words of wisdom?

TD

[gnetic86]

There's a really good book out on rebuilding 350s, very detailed and is worded in fairly plain english. That said it does get involved. I've never done it myself but I have a junk 350 longtail in my garage I wanted to explore (tear apart). I've been told its been rebuilt so all the internals should be good if you need anything. It was rebuilt but then removed due to a problem, but the person couldn't remember what said problem was (something stupid, missing check ball or something). They never got around to getting back to the builder to fix.

[1970gsx]

I did a 2004r in my last GN. Pain in my arse without the proper tranny specific tools. I have Mikey do them now.

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Originally Posted by 1970gsx

I did a 2004r in my last GN. Pain in my arse without the proper tranny specific tools. I have Mikey do them now.

I'm going to give him a call next. I'd rather try to keep money in the Buick community. I just called ATI. They want $1200 worst case to rebuild it. That's with the already have in it. Guess it's time to step up to the plate!!! If you want to run with the big dogs, you have to pay for it. One thing he told me was to step up to 3:90 gears. He said the 3:42 are putting a major strain on the transmission. He said that just that alone is worth a couple of tenths!!! Very knowledgeable guy. He was pulling numbers off of the top of his head like you wouldn't believe!!!

[GrndNatnl]

Gregg's rebuild was pretty cool though. It would chirp every gear at 1/10th throttle.

[timevacuum]

Hi Doug,

I've rebuilt two THM350s, a THM200C and two THM2004Rs so far. Having the GM shop manual and some snap ring pliers were key to the rebuild. For the 2004R, I used a few blocks of wood and a vise instead of the special spring compressor tool to install the spring plates in a few of the drums and it worked OK. I also used a spare yoke to hold the tail shaft when re-assembling the L/R gearing and clutches instead of that 'special tool'. Really it's not any kind of magic, just clean your workbench first and keep lint and dirt out of the trans during the rebuild. BTW use a dial indicator to check the clearances between the several sections of the tranny, (as specified in the manual). Usually the existing shims will be OK most of the time, but you can obtain different thicknesses as needed.

You'll be OK. I took me about 6 hours to do my last 2004R re-build, not including removal. re-install or shift kit mods.

Iceberg!

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Originally Posted by timevacuum

Hi Doug,

I've rebuilt two THM350s, a THM200C and two THM2004Rs so far. Having the GM shop manual and some snap ring pliers were key to the rebuild. For the 2004R, I used a few blocks of wood and a vise instead of the special spring compressor tool to install the spring plates in a few of the drums and it worked OK. I also used a spare yoke to hold the tail shaft when re-assembling the L/R gearing and clutches instead of that 'special tool'. Really it's not any kind of magic, just clean your workbench first and keep lint and dirt out of the trans during the rebuild. BTW use a dial indicator to check the clearances between the several sections of the tranny, (as specified in the manual). Usually the existing shims will be OK most of the time, but you can obtain different thicknesses as needed.

You'll be OK. I took me about 6 hours to do my last 2004R re-build, not including removal. re-install or shift kit mods.

Iceberg!

Thanks for the information Iceberg!!! I'm debating trying to do it myself or just let Mike do it. Mike is really good at what he does, so I'm leaning towards letting him do it.

I just got the Turbo 350 book from HP books. It doesn't look to complicated. Just a bunch of measuring and reassemble. I am a Journeyman Machinist so the precision tools are not a big issue.