[FC] Question about Powerslides.I NEEE

[James Davis]

Bob there is only one modulator for the Corvair powerglide.  It controls 
the harshness of the shifts (controls the pressure of fluid to the 
clutches).  The governor in concert with the springs in the valve body and 
the speed of the rear pump control the upshift/downshift points.  For the 
140, GM wanted to raise the shift point points to higher rpms.  They went 
from 4,400 rpm to 5,200 rpm at full throttle with a proportional increase 
in partial throttle shift points.  They did this by changing the governor 
weights (lighter than stock) and the valve body springs and piston 
diameters (stronger and bigger).  There were no changes to the transfer 
plate and the gears, clutches, and case.  The 67-69 powerglides have a 
different TV lever on the case but the internals are the same.  The 
61-63's  are very different and should not be used with a 164 cuin engine 
(although some parts of the transmission are the same).  Other than the 
shift points and the TV lever, all 64 to 69 powerglides parts are exactly 
the same and interchangeable. In fact, any TV lever can be used on any 
powerglide if the TV rod that goes with that TV lever is used on the 
transmission/engine installation.   It is just that the 64-66 TV rod won't 
work with a 67-69 lever and vice versa.
Jim Davis



At 08:17 AM 8/18/2004, you wrote:
>The 140 automatic has a different valve body and modulator, but the
>differences are small.  The modulator is also slightly different.  It has to
>do with the shift points.  Either can be used interchangeably and you can mix
>and match with no detrimental effect.  Paul in CT