Trans Help
Thread Starter
Heel & Toe
Joined: Jun 2007
Posts: 21
Likes: 0
From: Green mountain NC
Trans Help
I have a 85 vette the auto trans shift all 3 gears in about 20 mph only way tro get it to shift right is to do it manualy by hand any help would be great krazy glue
Race Director
Joined: Dec 2006
Posts: 10,383
Likes: 4
Peter K will know for sure but I think your trans is a derivative of the turbo 400, a 700r4. If so, check for vacuum lines that are off or leaking. Check the TV cable to make sure it's not broken and moves freely as the throttle moves.
Thread Starter
Heel & Toe
Joined: Jun 2007
Posts: 21
Likes: 0
From: Green mountain NC
Race Director
Joined: Jun 1999
Posts: 14,924
Likes: 9
From: Merritt Ils Fl
94z is close. 700R4 is very different than the 400. It does not depend on vacuum to determine shift points. Uses something called Throttle Valve pressure, plus other stuff. My SWAG (Scientific Wild Azz Guess) is your Throttle Valve cable is out of adjustment,like 94z said. Adjustment is not difficult and is detailed in all Corvette tech manuals.
Instructor
Joined: Sep 2004
Posts: 177
Likes: 2
From: Palmyra Virginia
How many miles do you have on the Tranny? My 85 was doing pretty much the same thing. After talking to a couple of people in the transmission business it seems originial trans are good for approx 100k before they really begin to suffer. Ended up having mine rebuilt(just got it home yesterday) and with better materials being used now the concesus seems to be that you should get at least 200k from the rebuild if you're not racing all the time. Haven't really had the chance to do a complete road test yet but does seem to be much firmer shift and the shift points are now much further apart.
Race Director
Joined: Feb 2004
Posts: 12,517
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Be sure to properly ste the tv cable as per the factory shop manual. Then, if the proble still persists, inspect the governor.
www.tvmadeez.com is a great site to understand the tv system, and what it does.
www.tvmadeez.com is a great site to understand the tv system, and what it does.
