Just swapped in a 700r4 from a 90 Impala out of a junk yard. Fluid looked good. After getting it installed and then taking it for a test drive, I only have reverse and low gear. If this was a 350 or 400 THM it would probably be a modulator or the line for it. Since these trans do not use va***m to shift, I am a bit lost and would appreciate any help. I did fabricate a bracket and did hook up the TV line. Everything else looks OK. any ideas? Could it be the governor? or? thanks in advance nfor any help diagnosing this
i bet you dont have the tv cable adjusted correctly.. it is crucial on the 700r4 to get the tv cable correct or the pressure isnt correct and you burn the ****** up very quickly.. you probably want to get a pressure gauge hooked up so you can adjust it.. http://www.tciauto.com/Products/Instructions/instructions/gm_tv_cable_adjust.htm
This is definately the place to start, it wont be much of an adjustment, to go from shifting too hard, to shifting perfect, to not at all! And its retarded hard to do get the initial setup. Once its close you can fint tune it, by the seat of your pants for driving style/comfort
I am not an expert on these trans but, I do not think it is a TV cable adjustment. I did play around with it and also have it adjusted the same way it is on my other (successfully) swapped in 700R4 in my other car. Should I still be advised to mess with the cable...what do I do? tighten it? loosen it? or? Besides a possible ( and I think unlikely) TV cable adjustment issue, what else could it be?
i had the exact same problem when i bought a rebuilt 700r . it would have low gear and reverse, drive wouldnt catch and acted like neutral. took it back and swapped the rebuilder for another trans and it worked. i never knew what was wrong though.
The TV cable controls the pressure inside the trans. If it's not adjusted right, it doesn't shift. There's plenty of info on the net about how to adjust them, if it's still not going then the next step is to check the line pressure on it. Maybe you got a bad one, it happens. I have a TH400 in a Suburban with a shot reverse/high band that the fluid is red and smells fine, they don't always burn up.
Go to http://purplesagetradingpost.com/sumner/techinfo/700R4p1.html for information. Note that the bracket on your carburetor is very important. The cable attachment must be at the right distance from the throttle shaft and at the correct angle. John
If the governor plastic gear is bad - broken , the trans will not shift. If the TV cable minimum settings is not correct , the fail safe check ball ( if installed) will seat and the trans will shift very late like WOT
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