<VV> Corvair Powerglide
tony.underwood at cox.net
Tue Oct 27 02:17:24 EDT 2009
OK, I have a PG question:
I've worked on so few Powerglides as to be ignorant of just about
everything in them because I never had one ever break on me. The
1960 4-door still has its original unmolested 200k+ miles PG.
Over the weekend I fixed its vacuum plumbing so as to smooth the
shifts out (mud daubers had stopped up the line to the vac. mod.
valve a couple years earlier when I had the engine out) and took it
out running today, enjoying shifts that didn't go THUMP. It had
been like that for some time, no vac. mod. function until I finally
got around to fixing the hoses etc.
I took the car across town, parked, then went back out and fired it
up to go back home and backed out of the spot, popped it into drive,
smoothly engaged, and I gassed it... transmission whined and the
engine flared up and the car barely moved. Off the gas immediately,
didn't wanna burn up the lining which can happen quick if it slipped
like that. Shut off, checked for ATF leaks, started up and
checked fluid level, ok.
Back in gear, SLOWLY moved forward, no slipping. Gassed it a bit,
whine and slip. In reverse, NO whine or slipping even when lugged
hard. Got it onto the streets, slowly up to speed, shifted sloppy,
engine rpm flared and mushed into gear but once in Drive it wouldn't
slip, drove normally.
Got to my side of town, and it wouldn't climb the hill to the
house. >:-o I was afraid I'd burn up the lining if it slipped
much so I backed down and stuck it in a parking lot at the bottom of
the hill... and crawled around looking for hints.
I pulled the vacuum hose off the line to the modulator valve just for
the heluvit and tried it again. Back to normal, albeit with hard
shifts... but NO slipping anywhere. Up the hill it went, no issues
So: PG gurus... am I on the last legs here? Or has the vacuum
modulator valve gone wacko (doesn't seem very likely)? And why
slipping in Low and not Rev.? Servo piston/valve? Is a band
adjustment likely to help here? As mentioned, I never had to fix
one so Powerglides are foreign territory for me other than what I've
seen in manuals. The transmission is quiet and smooth and fluid is
pink. To my knowledge it has never had as much as a screw turned on
it since it went into the car at Willow Run. I've owned the car
over 25 years now and this is the first transmission issue to come up.
Without that vacuum line attached, it works like it always
has. Attach the line, it's damned near unusable. I wouldn't have
thought it would make that much difference.
I welcome any input here... and I guess it's possibly time to dig up
a PG service manual.
tony.. (I do have another PG with 30,000 original miles on it if
need be but wanna keep this one, jus' b'cuz)
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