Howdy Y'all,
Since transmission fluid use was
beginning to show up once again on the 300 list server and since I've got a
'65 Dodge Dart with torqueflite that I bought that I'm SURE could use a pan drop
and fresh fluid, I thought I would run the whole fluids question by George
Riehl, trans authority in the 300 club.
I'm attaching the way I posed the
questions so you can best appreciate the very thorough answer he has
given.
Thanks to George.
Y'all might want to print this for
your notebook or save it to that important "maintenance" file.
NOTE he applies this to Powerflite,
early and late and later torqueflites.
Wayne
----- Original Message -----
To: George
Sent: Monday, August 07, 2006 4:11 PM
Subject: trans fluid
Hi George,
I see torqueflite fluid is in play again on the list
server.
Last I recall you said to use Type F in your
rebuilds. Still correct?
What about when I've got any other Mopar
torqueflite from the '60s and it is down a quart or two?
Do I add type F?
F can be hard to have in hand all the time - what about
Dexron-Mercon to top out?
If you were doing a pan gasket drain and refill (including
torque converter and filter) or a trans flush on a 100K mile car, what
would you suggest should go back in?
And may I forward your answers to the 300 list server and
the ForwardLook group?
Thanks,
Wayne
----- Original Message -----
From: George
Riehl
Sent: Monday, August 07, 2006 6:58 PM
Subject: Re: trans fluid
Hi Wayne;
The best fluid to use in the older P/F, T/F and
727s and 904s, is type F. If F cannot be found, type FA is O.K. FA has just a
little more "slip" additive. By no means use Mercon/Dextron. After a
period of use, M/D fluid will actually seperate the friction disc material
from the steel backing. Most other fluids will also damage the friction
material.
In "modern" day cars, the trannys are set
up to shift so that one cannot "feel" the shifting. So, the manufacturers have
formulated fluids with more "slip" additive. Slippage of the friction discs
causes gradual degeneration of the discs. The "old" T/F and P/F trannys
always shifteed a little harder than other auto manufacturers trannys, but they
did last longer. Generally, 70 - 100K miles, most GM trannies were shot.
In the past, GM/Ford owners bought "Chryslers" and hated the "harsher" shifting
and went back to other manufacturers. Chrysler trannys lasted well beyond 150+K
miles. This also applies to the 727 trannys.
Some time ago, Chrysler Performance issued
a bulletin about trans fluid and suggested that type F be used in all 727s used
in competition. This was the result from the "drag" racing
guys.
The "old" Type A-Suffix A fluid was
manufactured with a parrifin base material. When heated, the "wax" would turn
into crystals (like rock candy) and plug the passagages in the valve bodies,
resulting in trans failure. I have found this in a number of "used"
trannys that I have rebuilt that came from junkyards. One has to literally dig
out the passages with a screwdriver.
It is best to drop the pan and drain the
converter. Clean the pan and scren. AND, in some cases, drop the valve body and
clean it thoroughly. That will add life to a very good used tranny. And while
one is at it, readjust the bands (300s, front, 2 1/4 turns, rear band, 2
turns out) after tightening down both band adhustments with about 75 inch
pounds, then lock down the nut.
It's like giving the tranny a S, S, S and then a
good meal with new fluid.
And, when replacing the pan with a new
gasket, make sure that you "pound" down the raised bolt holes in the pan so the
gasket seals properly. Very important! And, please, do not use any
silicone sealer. Some tend to use way too much which in turn will "squeeze" out
and find the filter and plug it up. Bad news. Sometimes, even gets into the
valve bodies.
George Riehl
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