Had a mechanic/friend rebuild a th350 and put it in my 67 with a 326. It shift really hard out of first. He did the work in Tennessee and I was there to bring it back to Texas. Rather than make him redo it, I just said it was fine and went about my way.
What is causing this? Anyone know what would I would need to correct this? Is it another rebuild?
Mine did this after rebuild Check your modulater vac line at the trans and all the way up to engine look close at the rubber lines my vacuum hose broke off Shifted hard and late Make sure the steel line isn’t smashed or kinked also
A whistling sound (from a leaking diaphragm) White smoke coming out of the exhaust (from a leaking diaphragm) Early or late shifting. Hard shifts (usually causing the car to jerk) A rough idle. Low transmission fluid levels.
Last edited by Gus68; 02/21/1907:09 AM.
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I believe theres an adjustment screw on the modulater valve that can affect how it shifts. Ive never experimented with it but ive heard others talk of it
That TH350 uses a TV cable from the throttle linkage to the transmission...it has to be adjusted properly first. If not, you could wipe out the transmission.
The TH350 does NOT have a TV cable. The cable is a "kickdown" cable. We use to call it "passing gear". When you mash the peddle to the floor, the throttle lever pulls the cable out, causing the trans to downshift. That's all the cable does. It does not regulate the line pressure for normal driving, like TV cables do on the 200 4-R & 700R4.
Yes, this has been debated for years. But there are just too many guys who have run a TH350 for years, without hooking up the kickdown cable, with no problems. Lots of rebuilt TH350's don't even have the cable.
You can still read lots of debates about it, online.