Hey all, So I've apparently entered the twilight zone when it comes to rebuild costs for a BOP TH350. Calling around to a few reputable shops and I'm getting quotes of $2,000-$4,000 for a freaking stock rebuild. No way that's correct or have things just gone wacky?? "Master" rebuild kits on summit are in the $300 range. Obviously labor isn't cheap but i cant see that a TH350 would take a professional shop long to rebuild. Thoughts?
Is that them taking the transmission out, rebuilding it, and putting it back in? I suggest you keep on calling around.
Mark DeConti was our NE GS/GN club member that rebuilt transmissions for a lot of club members including me. He rebuilt a 400 for me with heavy duty parts about 9 years ago I think. It was 1100.00. Mark is DCM422 here on V8, but he doesn't frequent the board. You can e mail him and ask him what current costs are. E mail is dcm422@aol.com. Make sure you put "Transmission Question" in the subject line so he doesn't delete it.
That’s just the transmission. No car. Just open her and put new parts in. Called 7 shops total. Finally got one that said a stock rebuild would be 1500 with converter. I don’t need a converter but at least that’s reasonable comparatively speaking.
Do it yourself. It's really not that hard. You do need a couple specialty tools and it's very messy. But you will come out ahead. There are books out there and people here who will give advice.
A TH350 was the first transmission that I rebuilt back in high school. It is by far the easiest trans that I ever rebuilt. A universal clutch spring compressor, feeler gauges, a lip seal tool and common hand tools are about the only tools you need.
For $1500 or a little more I feel like you can just buy a rebuilt TH350 with a warranty? https://www.jegs.com/i/JEGS/555/603...mJ20PjeI-SsM1ngI9ZEnp94sJ3LBCTwxoCnyAQAvD_BwE https://www.monstertransmission.com...GPy_EGshNzAP8x-rp2U6oCYPDhKlehpRoC2CgQAvD_BwE
I build transmissions and a stock 350 would be $1,000 to $1,200 for me to do it and that's a side gig, not a fulltime shop. Here's the problem with building 400 and 350 transmissions now, I usually have to disassemble two transmissions to get enough parts to build one, sometimes three. There's a 40% chance the case is shot, a 50% chance the planets are worn out, and about a 70% chance the pump is shot. That means you have to use your own cores or buy those parts from a supplier, and if you buy them that's bank. Core's here are $150-$250 and the odds are that it's just plain worn out as well, these are 50 years old and have been rebuilt multiple times by now. If you do it yourself be SURE you buy American made parts, they are more expensive, but as they say "pay now or pay later" when it fails. If you want a hot rod 350, that's a whole different ball game, I do machining, add clutches, and replace a lot more parts, more money, lol. Thanks Brent
Yes if i had the time i would take this on myself. However, free time is hard to come by with a 3 year old and a 3 month old. So I'm looking to farm this service out.
Now this is some of the info I have been getting from the shops. 10+ years ago it was much cheaper and easier, however, parts are getting harder to source. The only thing I can think might be saving grace is that I have 2 complete TH350s in my garage. 1 came from my car, originally 350-2, and the other one was behind a 350-4. I know mine has about 100K on it and leaks out of the front and rear. Shifted fine though and ran through the selections and engaged no problem. That was 16 years ago when the car last drove. So maybe the hard parts inside are ok? Who knows.
IMO you should take one of the cores you already own and rebuild it yourself. As mentioned above, the T350 is not very difficult to rebuild and chances are very good that all the hard parts inside are in fine shape. Get a good kit from TransPartsWarehouse with all the good clutches, bushings, seals and steels and do it as your time allows. Add a Trans-Go shift kit and you won't be sorry. There are excellent publications available that will walk you thru every step. The GM Chassis service manual is a great place to start. Down-load the ATSG THM350 manual and the job will be at least as good as the local shop will do. If you are not mechanically inclined then have it done at a shop.
Judging from the number of times I have seen threads started with the exact complaint, this is becoming more common. Around here, TH350/400 transmissions are still plentiful and easy to find. If you were closer, for 4K I’d remove the trans, rebuild it, reinstall it, wash/wax the car, fill it with gas and smile. I’m thinking a lot of transmission shops just don’t want to mess with the older stuff. Maybe it is because the parts are harder to find, or maybe it’s because the profit margin isn’t as high as it once was or as high as modern stuff. They probably figure if they price it that high, it will scare you off. And if you agree, for that price it’s worth the potential headaches. Th350s are pretty easy to build. Very few special tools are needed, and what is needed is easily fabricated. Watch some YouTube videos, read some build tips and tricks, then decide if it’s something you want to tackle.
I figured cores weren't worth much. I've got a couple thatI doubt have ever been rebuilt. Guess I should hang onto 'em. Might want a hot rod one someday too. Hopefully you'll still be doing them.
My experience is a TH400 is the easiest to rebuild for a several reasons. One it is so tough, probably a minimum of replacement parts will be needed. There is no shortage of standard and upgrade parts for it. Some plastic parts were put in later production, I swap those out. And it is the only one built with switch pitch. Sure a few tools will make rebuilding a trans much easier, most of mine are home built. I got tired of lessor transmissions breaking, converted 200s, 300s, 350s, and some 4 speeds to TH400s. good luck, Bruce Roe
Ya, starting to look at the big picture and rebuilding it myself is probably the route i will go. I have easy access to a machine shop thru my work so i was thinking of having some of the parts clearanced to add an additional clutch and steel. Figure it couldnt hurt. Anyone have info on that in regards to how much to take off?
The equivalent of one friction and steel. The rule of thumb is .010 per friction. Place the uncut piston in the drum minus the seals. Stack up 4 frictions and steel plates, install the backing plate and measure your clutch clearance. Then measure your clutch/steel thickness, and doa little math to determine exactly how much to cut from the piston.
I was at our local trans shop recently programming a new techm for about the 100th time on the infamous GM 6l80/90 that he just rebuilt. I asked what an old TH350 trans rebuild "bench job" would cost, no race stuff, no converter and minimal hard parts. He said around $1000, maybe up to $1500. He has 40 years under his belt and his labor rate is $120/hr here in central NY.
