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i have a 79 elco with a turbo 350 tranny and it takes too long to shift? my tach or speedo dont work either. any ideas what it could be.
 

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So did you just acquire this car and these are problems it has? Or was all fine, and just all of a sudden it all went wrong at once? Are you suggesting they are related issues? If they are separate issues you might want to start threads in their rightful categories.

As far as a Th350 shifting late, it can be 1 of 3 things, Most common will be vacuum line has come off the vac modulator. and could be a defective vac modulator.#2, the Governor has hung up and the valve is stuck in the governor, or #3, the detent cable has become kinked or gummed up, and when you went full throttle at one time, the detent cable stayed out keeping the detent valve stuck all the way out. I'd check that vac line first and foremost. A better description of how the problem came about, or if you just bought the car this way or whatever the case may be, can be very helpful in a quick correct response.
 

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yea i bought it that way. i was just wondering if it was a little prob then i would fix now but if it isn't then i was going to leave it and focus my attention on restoring it.
 

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So long as it's not slipping in any gears, the late shift problem on a Th350 is USUALLY fairly easy to correct. As said, most cases it will be to do with the vac line coming off either at vac modulator, or at carb/intake end. Could even be a cracked dry rotted vac line. I've also seen poor routing let the rubber hose melt on a header. Check that line out from trans to intake, if all good, we'll go from there.
 

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I was driving my 68 one day and I noticed the further I drove the longer it took to shift until it just about wouldn't. I got under to find the rubber hose that goes from the metal line to the modulator valve was in a bind and collapsing. I took one off another part of the motor and it starting shifting like brand new!!!:nanawrench:
Donny
 

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on a 350 it uses the modulator to control part throttle low speed shifts .you can get an adjustable modulator to talor the shifts when you want them to come in.there is a adjustment inside the vacuum port.if you screw it out it makes the shifts sooner and softer,screw it in it makes them later and firmer. this only applies to the light throttle driveing shifts.when you are in the throttle enough to start engageing the detent which also changes the shift points.where are the shifts at wide open throttle. a 350 is probably the most tailorable trans i have ever worked on and used. check all of your vacuum line like everyone said then look at your modulator vacuum port for a adjustment screw. if i remember correctly there was a 2 or 4 turn limit on the adjustment either way.
 
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