<VV> ATF change

[Joel McGregor]

My wife's CTS also says not to change the transmission fluid but there is a transmission fluid life monitor just like the oil monitor.  I guess they couldn't decide.
We got the car at 60K and the first thing I did was change the transmission fluid.  It was the nastiest fluid I've ever seen in a working transmission.  I now run Dexron VI and Mobil 1 0-30 in it and change both every 3K.
My Corvairs get Mobil 1 5-30 and Dexron VI (if they use it).  I also change the diff and manual trans oil at 3K.  And before you ask - no none of them have automatic and manual transmissions.
I started changing my transmission fluid at 3K after watching a friend's 1985 C10.  He changed his fluid with engine oil changes.  He ran that 700R4 behind several engines including a supercharged 350.  It was still working fine when he sold the truck many years later.  If you will remember those early 700R4s were notoriously unreliable even behind a stock engine.
I haven't had any transmission issues since I started changing the fluid at 3K around 12 years ago.
"Changing" the fluid isn't like your engine oil anyway.  When I change the fluid in a 700 I'm only changing about 4 quarts.  The transmission holds around 12.  One more reason to change it so often.
Joel McGregor
________________________________________
From: James Davis [jld at wk.net]
Sent: Wednesday, May 16, 2012 11:36 PM
To: J R Read
Cc: Joel McGregor; virtual vairs
Subject: Re: <VV> ATF change

Quote the 1965 Corvair shop manual on page 7-31 - "No periodic draining
of the transmission oil is recommended."

On 5/16/2012 11:20 PM, J R Read wrote:
> Joel,
>
> 50,000 miles on an oil change is too many - even for synthetic.<GRIN>
>
> Seriously, why would you do that?
>
> Later, JR