Larry,

Guess you should followed this guy's procedure!

Regards,
Rob

-----Original Message-----
From: Larry
Sent: Tuesday, March 18, 2008 12:13 AM
To: gmclist
Subject: Drain Transmission & Torque Converter - COMPLETELY!

Rob,

You can take it to a "Jiffy Lube" type place to have them change the fluid, and to my way of thinking that is the only way to
*completely* change all of the fluid, as long as you have the filter changed also. The only catch is, the last couple of times I
stopped at a "Jiffy Lube" type place, they were *not* offering synthetic fluids as a change option. So you may have to make a sort
of deal with the owner/manager to use synthetic fluid. That being said, you can get most of the oil out using the following
procedure. Keep in mind, there are several...perhaps many... that would not do this (including IIRC Manny). I've done it many
times with no ill results. Sooooooo.....

This is a very messy procedure...you're gonna spill fluid, so be prepared with Oil dry, rags and the like to clean-up afterwards.

1. Do this with the trans cold. Wait at least over night.

2. Raise the coach high enough to get a 5 gal pail under it with room to spare.

3. Disconnect both trans lines at the radiator, and be prepared to catch the fluid coming out of the cooler in the radiator.

4. Attach hose extensions to the lines and drop the lines into the 5 gal pail.

5. Using two people, start the motor for only couple of seconds. Do this to identify which line the fluid will come out of. Now
you know
which line you *must* keep in the bucket.

6. Again, using two people, (one to run the motor, the other to watch the fluid) start the motor.

7. Run the motor until the fluid line begins spurting air. Shut motor off immediately!! The fluid will get quite frothy.

8. Allow to stand without the motor running for 4-5 minutes. This will let excess fluid in the trans drain down into the pan.

9. Start the motor again for no more than 5 seconds. Shut off the motor, This will pump out that last little bit in the pan and
make
dropping the pan a lot less messy.

10. Let the oil lines drip into the pail while you drop the trans pan.

11. Drop the trans pan, and replace the filter using two (2) "O" rings at the filter.

12. Hook up the two trans lines to the oil cooler at the radiator.

13. Fill the trans with about 7 qts of trans fluid.

14. Start the motor and allow it to idle for about 30 seconds or so before checking fluid level.

15. Check fluid level and add accordingly.

16. Once full, drive until normal operating temp is reached, and recheck fluid level. Add fluid to bring to "Full".

I've used this procedure on every auto trans that I've owned for....well....forever. This is just the way I do it....your mileage
may vary.

Just my relatively informed, off the cuff, back yard mechanic, gut level, eyeball it up and guesstimate, way of doing
things....that's all...

Larry
78 Royale w/500 Caddy
Menomonie, WI


-----Original Message-----
From: Larry

I had my 425 rebuilt last summer. Taking the trans apart was at times difficult because all of the internal seals in the trans had
turn soft and mushy. He said it was a good thing that the rebuild occured now because it probably wouldn't have lasted more than
another couple of hundred miles. When asked if I had used any transmission additives with the fluid, my answer was no, that the only
thing that the trans has seen is...when first installed I used Amsoil ATF and later, when I changed trans fluid because I had
trouble finding Amsoil, I had switched to Mobil 1. I don't know if any one else has experienced this but in my mind and the
rebuilders mind, there is to a minor degree, evidence that the two brands may not be completely compatible. So, FWIW, I would not
mix these two brands. JWIT

Other explainations are welcome.
--
Larry


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Larry,

I reckon that since you did use this procedure I'm surprised that there was enough Amsoil trans fluid mixed with the Mobil 1 fluid
to cause the mushy seal problem?

However, that statement is a SWAG as I have NO idea how much of the Amsoil was left behind.

An interesting experiment would be to take a brand new transmission, fill it with fluid recording the amount used, then drain it
using your procedure recording the amount you get out. That would tell you how much could not be pumped out.

Regards,
Rob M.

Larry,

Your suggested procedure includes "../fill the transmission with about 7
quarts of ATF...". If that really fills the transmission, you'll be
interested to read page 0-11 of X-7525. It says that a freshly overhauled
transmission holds 12 quarts. In other words, you still probably had about
a 7/12=58%/42% Mobil1/Amsoil mix.

No need for any messy experiment.


Ken H.

Along these lines, several years ago, majority of trans. shops had a
equipment that would flush almost all the old fluid and fill with new or we
knew how to do it without that equipment.
We did several trans. flush that way till we started running into a
situation where that unit we flushed would end up with a transmission
problem later.
We started hearing from other transmission shops about the same problem.
The best reasoning was that the new fluid has enough additives that loosen
up the old gunk that the gunk was getting stuck in the critical places and
creating problems.
We now change out what is in the pan only .


Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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