Hey guys I’ve got a question. I recently picked up a TH350. The guy told me it shifted great. The only issue he had was at 80mph his engine was running at 7-8000rpm. He said a shop told him it was a bad torque converter. I dropped the pan and found some tiny metal shavings on the magnet. The fluid looked good and the filter was clean. I don’t know a lot about transmissions so I figured I’d ask you guys what you thought.
If you put it in and it doesn't go into but will go into reverse it's likely the valve body. Ran into that with the th350 currently in my 53. Was a supposedly rebuilt trans we picked up for a customer car. Put it in said customer car and the highest it'd go was 2nd. Shifted great 1-2 and 2-1 but it'd stop at 2nd. Went into reverse fine too. Turns out the rebuild just consisted of new clutches and a slightly higher stall converter. Boss sourced another used th350 that worked and I bought the 2 speed th350. A b and m "stage 1" shift kit later(cheapest way to get everything to overhaul the valve body) and it crisply shifts into all gears. Decided then any th350 I get will get a shift kit
I bought a $50 TH350 off our local classifieds site a dozen years ago, in a garage in an alley in the dark. It works great and has a shift kit in it. I have doubts the engine was actually at 7-8,000 RPM. Put it in and see if it works.
Before you put it in, I would probably pop the governor out and make sure the gears not broken. It’s plastic. While you have it out, hold the governor up with the weights on the bottom. Collapsed the weights in and out and see it valve in the middle moves. I would also probably make sure the vacuum modulator is good. Other than that, you’re gonna have to put it in and see what happens, if you do put a torque converter in it, get a good one. Don’t buy some Daaco crap from the parts store.
Guy I got it from told me he had the governor recently replaced along with speedo gear and modulator. I’m going to be putting this in my 60 C10 with a 283. I’m going to pull the old straight six out. So I’m planning to just get a new converter and adding a shift kit.
Will be pretty easy. I am pulling the old straight six and 3spd out of my 60 c10 and putting a 283 and th350 in.
so you'll have to figure out the crossmembers...perhaps remove the one that currently supports the bellhousing, and add one for the back of the engine, and you'll also need to add side mounts for the engine, instead of the front mounts it had.
Yea Ive got a custom crossmember from CaptainFab coming. I just received the 67-72 motor mounts yesterday. I will have to remove the current crossmember.
Yes CaptainFab told me he always recommends the 67-72 C10 side mounts. Says worst case is I have to add a 1/4" spacer on top of the frame. The trans mount he makes for the 60-62 swb for a TH350 bolts into existing frame holes so will make side mount locating easier. https://customfab-cda.com/ Thats his website. He has supplied alot of custom parts for guys with C10s.
I would probably check it anyway. Make sure it’s free. Depending on the shift kit you may have to change the springs in it anyway. Biggest thing is just don’t get some junk cheap converter! Then you will end up with metal in the pan.
Like @Kevin Ardinger said , Check Governor gear also , easy to do. I recently Lost 2 & 3rd on Fresh build , Governor was set up too tight ! A ATI Built trains from Md , First Time that I experienced this , There should only be around .010-.020 tho Clarence between Cover & governor, The Non OEM gear I installed after Stripped a Tooth , Replacement Gear was .100 tho to long & .010 tho to round , Needed to be File & sanded to OEM Spec . The RPM's mention above sounds Unrealistic on Average parts used in a engine to Exceed the 7K & North of ,
A 350 has a non-lockup convertor. There just isn't too much to go wrong inside the convertor. If the stator clutch locks up you would have a hard time getting any high rpm out of the engine and the trans would probably overheat. If the stator clutch slips, you won't get any torque multiplication at low speed. It would be a dog on take off. About the only other thing to fail would be the thrust washer for the turbine. If that fails it acts like a really high stall speed convertor. It would take a good amount of rpm to get the car moving.
I should add that if I bought a used THM 350, the first thing I would do would be to disassemble it for inspection. I'd be hard pressed to put into something without making sure it was up to parr.
I don’t know anything about the inner workings of a transmission. I’d be worried I would screw something up putting it back.
Knowledge of working needed & required on Automatics , Not like a Manuel, There is a few unique tools also needed . This book is worth the $20
In my experience, every TH350 has something wrong inside it...including the ones that still work... but you can also just put it in and try it.
Might have been exaggerating, folks today think that if an engine is turning more than 2000 rpm at highway speeds, it's gonna blow up
A few weeks ago I drove my Supercharged home 1-1/2 Or 2 miles @ 3000 Rpms in 1st gear , @ 45 ish Mph It sounded Like 6,500 The converter is real tight , I use a tight converter with small tires set up , & big tire I use 4,500
Drove my 46 all the way to Seattle and back with the 455 Buick and TH400. Runs at just about 3,000 rpm at 75 MPH. You're right, over 2,000 rpm at highway speeds scares people now. Many people just shouldn't have tachs.
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