GM power glide automatic gear box vacuum controlled kick down

[Guest bornil47]

Does anyone knows how to adjust the vacuum controlled kick down function at GM power glide gear box ?

 

[Mark Shaw]

I have been working on a 1969 Olds Cutlass that has a throttle solenoid.  The book says it should be adjusted to move only 5/8" when activated.

[misterc9]

What year and model is this?  Power glide downshifts were usually controlled by the throttle rod adjustment.The service manual showed a procedure and specifications to adjust the rod from the throttle to the transmission. This adjustment would also affect  the normal driving up shift speeds.If the modulator was bad or didn't have correct vacuum it wouldn't shift right. The modulator needs manifold vacuum not carburetor vacuum.

[NTX5467]

What year and vehicle is this PowerGlide in? What type of operational issues are you seeking to fix?   Just curious.

 

IF the PowerGlide does have a vacuum modulator on the side of the case (they're usually on the passenger side on the THM350, 400, and similar) AND the throttle "kickdown" rod. the vacuum modulator adjusts the basic trans fluid pressure for altitude compensation.  On the THM350 and such, with no kickdown rod (as it's done with an electric switch on the throttle linkage on the 400s), the basic shift points are determined by the trans governor and the part-throttle downshifts are controlled by the vacuum modulator.

 

The service manual had information on transmission fluid pressures, plus any kickdown rod adjustments.

 

Take care,

NTX5467