Trans not downshifting on 1987 S4
#1
Burning Brakes
Thread Starter
Trans not downshifting on 1987 S4
O.k. After looking at trans and messing with Bowden cable pull pan and see bowden cable is hooked up. R & R valve body see stuck valve. Send valvebody out to Blue Mountain repair shop . Just installed same crap. Think still in valve body. Any ideas here
#2
Ive been dealing with the same thing for the last year. Same findings. Changed fluid, Kick down solenoid and relay, Modulator valve, vacuum line to trans. Even had the valve body cleaned professionally. Car drives great , just no kick down or down shift. Oh and my car is a 84
#3
Rennlist Member
Have you measured the Governor pressure? Is it to WSM spec? Downshifting occurs when Governor pressure (dependent on road speed) is higher than Control pressure (controlled by Bowden cable via the Control pressure valve in the valve body.) If the Governor isn't producing high enough pressure to overcome Control pressure the shift Command valves inside the valve body will never move to allow downshift. You can remove and clean the Governor with the transmission installed in the car.
Mike
Mike
#4
Race Car
Ive been dealing with the same thing for the last year. Same findings. Changed fluid, Kick down solenoid and relay, Modulator valve, vacuum line to trans. Even had the valve body cleaned professionally. Car drives great , just no kick down or down shift. Oh and my car is a 84
#5
Burning Brakes
Thread Starter
Ammonman thanks will look at it. I hope it fixes it. Mickster ,Bowden cable controls kick down even if switch inop.
#6
Burning Brakes
Thread Starter
Pulled the governor cover and the governor moved freely.
#7
Rennlist Member
Did you remove the Governor and verify that moving the centrifugal weights moves the Governor valve? If so, I would find a pressure gauge set-up and measure Modulating pressure and Governor pressure. Modulating pressure is adjustable and will affect governor pressure. Governor pressure is not adjustable on it's own.
Another thought, you verified the Bowden cable is connected in the trans but have you verified that moving the throttle moves the Bowden cable at the trans end? Also, is your throttle cable adjusted correctly? This can affect the Bowden cable and thus the control valve position.
Mike
Another thought, you verified the Bowden cable is connected in the trans but have you verified that moving the throttle moves the Bowden cable at the trans end? Also, is your throttle cable adjusted correctly? This can affect the Bowden cable and thus the control valve position.
Mike
Trending Topics
#8
Former Sponsor
#9
Burning Brakes
Thread Starter
I do have Bowden cable and throttle cable set up properly . I did check cable moved in trans with throttle movement. Going to borrow some gauges since no one has locally. Snap On said 3 days till they can get them. Thanks Greg did not know that. The trans also has early up shifts . Which leads me to believe its a pressure issue. But can't tell that till I get gauges on it.
Note ...I just checked movement well governor was still in car. Will pull it today and check.
Note ...I just checked movement well governor was still in car. Will pull it today and check.
#11
Burning Brakes
Thread Starter
Don't have time to wait borrowed my buddies gauges. Took trans pan down. And adjusted bracket so I could get full movement on the pressure valve. Will refill and take for another test drive. With pan down I know Bowden cable is working so I can go on to next step.
Last edited by dzaprev; 03-16-2014 at 09:16 PM.
#12
Burning Brakes
Thread Starter
Took trans pan dow and let someone press throttle all the way down and made sure pressure valve goes all the way in. I think cable was stretched on my car and possible bracket bent. I bent bracket then adjusted cables over and checked for full movement of pressure vale at valve body it was only going in a little more then half way before adjustment. After adjusting and seeing that I had full movement I refilled and test drove and it downshifted . Hope it helps anyone with similar problem . P.O. had everything so screwed up .
#13
Today after reading a lot of posts about Trans-X I decided to put a bottle in. I removed a quart from the pan and added the bottle. So far Ive got shifts that seem smoother and the gears are holding to higher more appropriate RPM's. I even got a kick down on the way back from lunch. I'm hopeful.
#14
Burning Brakes
Thread Starter
I had a stretched cable. Took the cable and routed with some tie straps to take slack out. I lowered the trans pan to make sure pressure valve was all the way in on full throttle. Cranked up the modulator 2 1/2,turns and driving beautiful.FINALLY