200-4r Starts Out In 2nd Gear

[MCTURBO]

Ever since I installed a Super-Servo the car wants to start off in 2nd gear (or it's a real fast shift from 1st to 2nd). Manual 1st gear works fine. Also I tapped & installed a fitting in the servo cover & I only get 10 to 40 psi depending on RPM. What could make the car start in second ??? TIA.



Pete Carnelli
Charleston, SC

 

[MeanBuicks]

I'd be careful there!

The servo is not a control element. In other words, it is not involved in the 'decision making' process as to what gear the transmission should be in. That's the job of the governor and valve body.

If your transmission is favoring second gear after merely installing the servo, I'd be concerned that the band clearance is inadequate. It may be dragging on the drum which will hurt the band/drum if that's the case.

Those pressure readings don't sound too good either. Did you tap directly into the center of the servo cover? Are you sure that the fitting you added isn't pushing on the servo pin?

 

[blackplague]

Steel Accum piston?

When you installed the super servo, did you install the steel accum piston from the old servo to the new super servo? I don't believe that the super servo is machined for the little nose of the steel accum piston. That will take up some of the band clearance.

Servo pressure should be within 10 psi of line pressure.

 

[WE4]

Only way servo is the culprit, is if you got it too tight on band clearence but in Manual low it would drag or try to pull down. But Like Greg, I think its probobly a control problem.


Bruce
WE4
www.ptsnctb.com

 

[transfixleo]

Is that 10-40 PSI at a standstill or when the servo is applied (2nd , 3rd and 4th)?

 

[MCTURBO]

The 10 - 40 psi is in second. First has 0 psi and third & fourth has 70 psi or so. The TV is hooked up so it's not at min or max it is following the throttle, which is why I said 10 - 40 psi depending on RPM. Thanks for you interest.

 

[transfixleo]

Sounds like you have a massive leak. You should have line pressure on the servo. I would start by putting the stock servo back in and seeing what happens but unless you have broken rings I would doubt that it is going to fix it but who knows until you try it.

 

[MCTURBO]

Replaced the Super Servo w/ the stock servo, no help. If the 1-2 shift valve were stuck would the trans still go into 1st manual ? Some one suggested that there may be a crack in the case. Is there a method for checking the case for cracks other than visually (i.e. dye penetrant or something).