The Stovebolt Site Forums The Shop Area Engine Shop powerglide gurus unite!!!!

>>>>>i just bought a 65 c-10 with the factory automatic transmission. the powerglide, when put into gear, (espeacially reverse)has a slight delay and then VIOLENTLY shifts. it moves the whole truck, this being the first automatic ive ever had, i dont know what might cause this but i know its got issues.<<<<<

Ok First of all disregard the above comments on the modulator, as the modulator only controls up-shift/down-shift depending on road speed/vaccum.

Now as to what you are experiancing when shifting from park/neutral into drive/reverse......

First you need to look at the one-way sprag clutch/band..... in drive/low the clutch/band allows an internal ring gear to turn with the the sun/planitary gears for forward drive of the output shaft. When you shift into reverse, the hydraulic fluid pressure applies either a one-sprag clutch or a band to the outter surface of the ring gear forcing the planatary gears to walk around the sun gear forcing the output shaft to turn opposite direction of the input shaft, thus creating reverse.

It sounds like you either have a mechanical problem in the sprag-clutch or the sun/planatary/ring gear system in your transmission. although you could also have a problem within the valve body creating abnormally high line pressure on the hydraulic side as well..

either way you have two choices.... hold the tranny up to the phone and I'll take a look at it.... or drop me a line and lets re-build it....
Either way? It's time to pull the tranny and have it gone through... before it leaves you sitting somewhere along side a dark and lonely road... because that is exactly what it will do....

Michael