700R-4 Shifting Late
#1
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700R-4 Shifting Late
I notice during normal part throttle city driving that the transmission seems to want to shift a little late than usual. Also, during wot the tranny won't shift unless i let up off the gas. From what I've read, adjusting the TV cable isn't good for the tranny, and that new springs or weights, and (or) a new governer is usually what fixes the problem. Any advice to as to what solutions could be of best fit to this problem? It's not really a serious situation for me but the 700r4 is supposed to be recently rebuilt, just a little concerned.
Thanks,
-Robby
Thanks,
-Robby
#2
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Car: '86 Camaro, '02 WRX, '87 K5, '67
Engine: 350 TPI, 2.0turbo, 383 in the works, 289-4BBL, 232, A-head 4-cylinder
Transmission: T56, 5-speed, 700R4, C4, T176, semi-auto 2-speed
Axle/Gears: 3.73, 3.90, 4.88, 3.55, 3.54, 7.00
Have you done the automatic adjustment procedure on the TV cable? If so does it still have travel in the mechanism? If not replace the cable. If so then the cable is set properly. Don't try to adjust the shifts with the TV cable. This is a bad idea than never works, and can ruin the trans.
Changing governor weights/springs is to adjust the WOT shift RPM. I don't think this is your problem either, and I wouldn't go screwing with the governor unless you want higher or lower RPM shifts at full throttle.
Changing governor weights/springs is to adjust the WOT shift RPM. I don't think this is your problem either, and I wouldn't go screwing with the governor unless you want higher or lower RPM shifts at full throttle.
#4
at wide open throttle governor pressure must be higher than tv up pressure that is sent to the shift tv valves to delay upshifts via the tv cable or there wont be an upshift wothout backing out of the gas which lowers tv upshift pressure.if the trans was working fine and then developed this problem ,then you must verify that the governor valve is opening all the way allowing it to generate a pressure equal to line pressure at wide open throttle.remember tv upshift oil is not 90psi at idle and 200 at wot like line.it is fed between 0 psi at idle and 90 psi wot from the tv plunger and sleeve /tv valve combo which is fed 90 psi from the tv limit valve.it multiplies shift delay force at the shift tv valves in relation to the diameter of the valve land it is exposed to.does it shift late at minimum throttle angles?
#5
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Yes, when at normal/partial throttle shifting it shifts quite late. Also, when I back off the throttle to try and keep it from going so unnessacarily high in rpm at partial throttle, it hesitates before upshifting.
So the throttle governor pressure is at a higher psi than the tv up pressure, which is directed to the shift tv valves?
So the throttle governor pressure is at a higher psi than the tv up pressure, which is directed to the shift tv valves?
#6
tv upshift is higher than governor when it should be lower.things to check after the governor is the tv valve and the tv upshift valve or governor screen for a restriction.shut off the car and hit the gas pedal 20x to try to unstick the throttle valve connected to the pedal via the tv cable.start car and road test.what does it do know?does it shift earlier?this can also be verified with a pressure gage,although most wont have one so try what i suggested.post results.
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