<VV> PG problem

[James Davis]

If you idle rpm is set to 600 rpm in neutral (500 in drive) then check the 
engine vacuum.  It needs to be better than 14 inches and 16 inches or 
better is perfect.   If all that checks, then it is either the vacuum 
modulator valve is stuck and not moving.  All it takes is some lint to 
stick the valve.  Just take the modulator out and see if you can move the 
valve with a magnet.  Make sure it moves with no drag.  If that not it, 
then you need to check the hydraulic modulator valve.  The easiest way to 
check that is with a pressure tap. It is the pipe plug on the bottom of the 
front pump cover.  You are looking for 52 to 64 psi at idle neutral, vacuum 
line attached. I would bet on a stuck vacuum modulator valve.  I assume you 
have the downshift timing valve in the correct way (the pointed end down).
Jim Davis

At 04:30 PM 9/8/2004, Dave Ziegler wrote:
>Help1 I'm stumped and need some help with a powerglide problem.
>The car: 1965 4-dr 110 H.P., automatic transmission
>The problem: when shifted from neutral to drive, it bangs hard into gear.
>What I've done: replaced the modulator (twice) made sure the valve was free.
>No difference. Made sure ALL vacuum lines were tight(no leaks). No
>difference. Replaced transmission crossmember mounts. No Difference. Reading
>a post by Steve Oxford of last April, he solved the same problem by changing
>the torque converter. I don't understand why but I went ahead and changed
>the torque converter. While apart I discovered the differential mounting
>flange was broken from the starter hole to the bottom. I also replaced the
>differential. No difference. Now grasping at straws, I removed the pan and
>removed the valve body. The valve body was dis-assembled on the bench and
>thoroughly cleaned. I made sure all the valves moved freely. It was  then
>re-assembled and re-installed with new gaskets, fresh Dextron, Throttle
>valve adjusted, low band adjusted. No difference. Car still bangs into
>drive, reverse seems to be okay. After running for a few minutes and
>shifting through the gears, the shift got progressively better until it
>didn't bang going into drive. I thought I had it. After sitting for another
>few minutes, running, no shifting, I put it in drive--BANG
>What am I missing or am I just stupid? What's going on here? Anyone have any
>ideas or suggestions? I'll take any or all the help I can get here.
>Thanks in advance,
>--
>Dave Ziegler
>Corvair Therapy
>Mechanical repairs
>Minor restoration
>Dave.. .
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