<VV> 140 PG swap complete - PG fluid level theory?

corvairduval at cox.net corvairduval at cox.net
Mon Jun 9 15:36:59 EDT 2014

I would like to know what seal could have more pressure on it due to an
overfilled condition. Just due to gravity, the pressure could not be more
than a few psi difference. 

The owners manual stresses not to overfill for the reason I listed -
foaming. It makes a mess, plus foam does not pump well.

I was only explaining the need to check the fluid level with the engine
running, not the extra part of needing hot fluid. Most all the other fluids
on the car are checked with the engine off, even if the fluid should be
warm first. And one should have some fluid in the Powerglide before running
it for the first time. Do not start it dry. Running vs not running is an
inch or better on the dipstick. Cold vs hot is only  a fraction of an inch.
(Note to nitpickers, .99" is still a fraction of an inch!)

Frank DuVal

Original email:
From: Bill Hubbell whubbell at verizon.net
Date: Mon, 09 Jun 2014 14:57:13 -0400
To: chaz at properproper.com, virtualvairs at corvair.org, corvairduval at cox.net
Subject: Re: <VV> 140 PG swap complete - PG fluid level theory?

Well, both are true.   The level drops somewhat when the transmission is
pumping, BUT the fluid also expands when hot.  This is why the operator's
manual tells you to check the ATF level with the "transmission at operating

I know you CAN blow out seals if the transmission is overfilled, especially
on older transmissions with worn seals.  The owners manual makes a big
point of saying: DO NOT OVERFILL. 


On Jun 9, 2014, at 2:29 PM, "corvairduval at cox.net" <corvairduval at cox.net>

Too much confusion here. Let me add to the confusion:

1. Add Dexron I, II, III, IV, whatever you have on the shelf, to the
transmission with the engine OFF to the full mark. This is what Bryan said.

2. Start the engine. Check the ATF dipstick. If it is below the add mark,
add Dexron to slightly above the add mark. I usually do 1/2 way between
full and add. Note, the distance between Add and Full is one Pint, not one
quart, IIRC.

3. After a drive or warm up period, check the fluid level again. If below
Full, add up to full mark.

4. If you overfill the Power Glide, it causes the ATF to foam. This results
in poor shifting and ATF blowing out of the dipstick hole. There is a small
vent hole about 1/2" below the dipstick opening. Makes a mess on the engine
sheet metal. No seals should be harmed. 

The level of ATF drops when the engine is running because the fluid resting
in the pan is now pumped through the transmission. So you need to take a
running level, as the rest level will change depending on several factors,
so it is unreliable for measurement.

Frank DuVal

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