Re: [ihc] 727 Rebuild & Shift kits?

[Colin M Rush <salmineo@xxxxxxxx>]

The radiator is a potential leak.  Per a technical bulletin published by
Raybestos Powertrain:  

"New fluid can actually cause water damage! 

Just because you didn't see any sign of water damage during a rebuild
doesn't mean you're off the hook...

You just rebuilt the transmission and flushed the cooler. Now the
cooler's clear, and the pump's pushing fresh ATF - under pressure -
through the cooler. Fresh ATF that's loaded with active dispersants and
detergents,

As these active ingredients flow through the cooler, they come 'in
contact with those hairline cracks or pinholes. So even though the unit
didn't come in with a water problem, that water problem won' t be long in
coming, as fresh ATF washes away the varnish and sludge that blocked the
crack.

And no matter how good a job you do rebuilding the unit, if you don't fix
the water problem, your rebuild won't last. But a bad heat exchanger's
just one way for water to get in and destroy your transmission."

You can read the rest of the article here:
http://www.raybestospowertrain.com/content/techtips/tech_tip_water.html

Raybestos published that article in an effort for transmission techs to
reduce callbacks and warranty repairs.  Many transmission guys (myself
included) will not warranty rebuilds unless the radiator is replaced. 
The upshot is, you need to have your radiator rebuilt when you rebuild
your transmission, or run the risk of having your trans made into junk by
a bad heat exchanger.  Bypassing the cooler in the radiator will prevent
any leakage, but the radiator heat exchanger does more than just cool the
trans, it also helps it warm up quickly.  Cold transmission fluid is
easily overpressurized, and can cause the rear servo to come out in
reverse, harsh shifts, broken bands, and a noisy clunky transmission.  It
is better to rebuild or replace the radiator, or if you must get an
external cooler, buy one of the Earl's units with a
thermostatically-controlled bypass valve that only lets the oil go
through when it is hot.  
-Colin

---I have seen some aresol type line and cooling system flushes. Can that
be used insted of replacing the radiator?---
Thanks Again

R.T. Sekhon
1979 Scout II 
Dallas,TX