<VV> BG Services for Corvair powerglide transmissions

[James Davis]

Well, the same 1965 shop manual recommends 6,000 mile engine oil 
changes but I know of only few that go that long.  Of course that was 
with 10W-30, SC conventional oil.  With the transmission, I think it 
is a sludge issue.  As stated the torque convertor will trap any 
heavy particles in the transmission oil .  One only has to go to 
Cookville, TN and see what they flush out of the typical torque 
convertor after it is cut open on a rebuild to understand why clean 
fluid is a necessity.
Jim Davis

At 03:52 PM 2/23/2006, Norman C. Witte wrote:
>Is this a situation where the factory is being overly cautious, to the
>benefit of its dealers?  (Ok, so that last bit sounded a bit cynical, but
>it's also true.)  The reason I say that is that I always understood the
>Corvair Powerglide to be a particularly robust unit, and generally I thought
>the rule for changing power transmission fluid was to smell it and look at
>it on the dip stick.  If it's burnt, it's bad.  Otherwise, long may it wave.
>I'm not saying that that is the shop manual approved approach but with so
>many PG Vairs on the road I suspect that there is a lot of real world
>support for my approach.  Of course, a more cautious approach is warranted
>in dune buggies, Ultravans, and trucks that are actually used AS trucks
>(don't know how much that happens any more, 'cept maybe tim coulson).
>
>Norm Witte
>
> > -----Original Message-----
> > From: virtualvairs-bounces at corvair.org
> > [mailto:virtualvairs-bounces at corvair.org]On Behalf Of James Davis
> > Sent: Thursday, February 23, 2006 4:40 PM
> > To: virtualvairs at corvair.org
> > Subject: Re: <VV> BG Services for Corvair powerglide transmissions
> >
> >
> > Err, you might want to pick up a copy of the 1965 Corvair shop manual
> > and reread page 0-8 on "Transmission - Powerglide".  GM recommends a
> > 2 qt fluid change at least every every 12,000 miles.  According to
> > Castrol, any time  a conventional transmission oil exceeds 160 F the
> > life of the oil is compromised.  Using a synthetic or synthetic blend
> > can improve its temperature tolerance.  Just how much Castrol
> > wouldn't say.  Then there is the contamination issue.  Remember the
> > Corvair Powerglide has no transmission oil filter, only a
> > filter screen.
> > Jim Davis
> >
> > At 03:20 PM 2/23/2006, Brent Covey wrote:
> > >Hi Randy,
> > >
> > >Normally the fluid in a Powerglide will not need replacement
> > for the life of
> > >the car, Corvair Powerglide is a very cool running
> > transmission and the
> > >fluid doesnt degrade much over time. If you were pushing a
> > Corvair hard
> > >enough to be hard on the transmission you'd be going thru
> > engines fast, the
> > >trans is harder to overheat than the engine by quite a long
> > shot. In 25
> > >years I havent encountered an overheated seal in a Corvair
> > Powerglide; on a
> > >regular GM car theres often heat damage.
> > >
> > >Hope thats some help,
> > >Brent Covey
> > >Vancouver BC
> > >