From: John De Armond
Subject: Re: Are Trans Sealers Really So Horrible ?
Date: Wed, 22 Dec 1999 17:02:30 EST
Newsgroups: rec.autos.tech

Shrub7 wrote:
> 
> I have a leak in the trans of my 85 Chevy Caprice. It is slowly getting worse.
> The only place I have to park it is on the road in front of my house and the
> embarrassment factor is coming into play.
> 
> I am tempted to use a trans sealer. Has anyone used one and had the trans
> survive for more than, say, 1 year??  I keep hearing that the trans sealer will
> expand the gaskets until they actually stick into the trans's inner workings,
> and screw it up. But I have NEVER heard anyone say "Yes, I used a trans sealer
> and it ruined my trans". I HAVE heard one guy who used it in a Cadillac say it
> fixed his leak and his car was OK for a year, but I don't know if it croaked
> one month later or something.....

I don't work on FWD cars so when wifey's 90 Camry started leaking
xmission fluid, I suggested she dump some leak stop in.  About a
month later, the tranny wouldn't go in gear.  Had the tranny shop
next door pull the tranny.  Watched the guy take the thing apart. 
O-rings were jelly. Could be squeezed apart with the fingers. He
said he sees that a lot in jap cars where tranny sealer has been
used.  Cost me a junkyard tranny and the labor to install it for
what turned out to have been loose pan bolts :-(  

OTOH, I've used this stuff in older cars with good success. 
Something that works at least as well in my experience is simply
adding 4-8 oz of lacer thinner to the fluid.  It does the same thing
as the tranny sealer does - soften and swell the O-rings and seals. 
At the concentration mentioned, it seems to be somewhat less strong
than a can of tranny sealer so it's a good intermediate remedy to
try.

So.  My one line advice would be.  Try it if you dare.  But be ready
to tromp the junkyard if it fails.

John