Transmission - Auto Tranny Maintenance

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Date: Mon, 13 Apr 1998 18:42:29 -0700
From: Jim Brink 
Subject: Re: auto tranny maintenance

Kevin Valentine wrote:
> 
> I'm thinking of changing the fluid in my automatic transmission and
> wanted to check with the list of any tips you might have for doing so.
> What is the procedure,  in a nutshell?

I always like to drop the pan and screen (filter) and give each a
thourough cleaning. In addition, I pull the cooler lines and let them
drain as well (engine off). For a real auto. trans. service, the torque
converter should be drained but there are no provisions for this on a
Toyota (Ford is the only manufacturer I know of off hand that does
this).

For worst-case situations like burned fluid, I will service the
transmission two or three times, circulating as much clean fluid through
the transmission as possible.

Here is a simple procedure:

Pull the A/TM dipstick out of the tube slightly

Drain the A/TM fluid pan through the drain plug

Remove the pan bolts two at a time, leaving two or four bolts loose at
the front but still in the trans. case to allow the pan to drop a little
and allow excess fluid drainage.

Remove the pan completly noting the condition of the dipstick tube
o-ring and replace as needed.

Gently pry the valve body fluid tubes away from the valve body.

Remove the screen attaching bolts and screen.

Clean the pan and screen completely and check the screen for tears or
other damage.

Blow dry the screen and pan. Do not allow any lint from a shop towel
near the pan or screen.

Reinstall the screen and tubes. Make sure the pan magnets are
reinstalled in the pan if they were removed.

Check the flange on the oil pan for flatness and tap the edges of the
bolt holes flat if they are bent slightly.

Place a new gasket onto the pan. You may use a SMALL amount of gasket
cement (Like Gasgacinch) to secure the gasket to the pan but don't over
do it. The last thing you want in your auto tranny is gobs of RTV.

Guide the pan into place, making sure not to disturb the gasket and line
up the dipstick tube.

Install the pan bolts and torque in an even pattern. Do not overtighten.

Fill the transmission with ATF until it reaches the HOT FULL line. Start
the engine and add fluid until it reaches the COLD FULL mark. Shift the
transmission through all of the gears two or three times and recheck the
fluid and maintain the level. 

When the engine is at normal operating temperature, add fluid until it
is at the FULL HOT level again. Remember, add slow so as to not overfill
the transmission.


- -- 

Jim Brink, Toyota/ASE Certified Technician	1986 Toyota Std. Bed 4WD
Manhattan Beach, CA				32x11.50/15 BFG M/Ts
ToyTech@Off-Road.com
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TLCA - Friends of the Mojave Road (FOMR) - CA4WDC

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Date: Mon, 13 Apr 1998 18:39:36 -0400
From: Darren Floen 
Subject: Re: tranny fluid change

This is the fastest way to get a couple quarts of new fluid into the
tranny,but it is the wrong way to do a fluid change.

 The right way to do a fluid change is to drop the pan,change the
filter,and adjust the bands(if neccesary).Your tranny will thank
you.This method doesn't get all the fluid from the torque converter,but
its the accepted method,and it gets most of the fluid out.

  Running an auto transmission at any time with a lack of fluid will
damage:Cluthes(reqiure constant application pressure,or
cooling),Bands(same reason),seals(lack of lubrication),bushings,
bearings and thrust washers(lubrication) and the converter can be
damaged.

This is not a flame.Just a minor correction.

Darren

Edward C. Fisher wrote:
> 
> Kevin:
> 
> The best way that I have been told to do it, and actually I have done it
> this way, is to disconnect the output side of the A/T line at the radiator.
> Point it in a bucket, and pour tranny fluid in the filler tube (dipstick
> tube) while the vehicle is running.  If it quits pumping, just goose the
> accelerator and it will squirt out again.  Try not to run the pumps dry, but
> if you can't dump it in as fast as it is pumping out it is no big deal.
> After I pumped through 10 quarts, I reconnected the line and called it 30
> minutes of good maintenance.
> 
> Ed Fisher

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Date: Tue, 14 Apr 1998 07:30:17 -0500
From: "Edward C. Fisher" 
Subject: tranny fluid change (long)

I was given this method of chasing out old transmission fluid by a 20+year
Toyota technician.  No, he is not from the 'old school', as he has just
completed yet another training for the newest Lexus repairs in Florida.  He
is also the leader of a team of techs at his dealership.  This is how he
does it at the dealership, and I would imagine he is not the only one, at
the only dealership, to use this method.  I did forget to mention cleaning
the screen, but I do not do that on every fluid flush.  This method is more
than just a way to 'get a couple quarts of new fluid into the tranny', this
method runs the new fluid through the converter, which is a more thorough
flush.  I did not intend for anyone to run the tranny dry for an extended
period, and for the few seconds which it may be low I have never experienced
any ill-effects on the many that I have done this way.  A case in point is
my wife's Camry that has 154,000 miles and still shifts sweetly. It has been
flushed this way many times. 

I also posted that valves can be set at .007 and .011 cold.  Again, this is
what is being done by at least one superior Toyota expert at at least one
finely run shop.  I have set mine cold, brought the vehicle up to operating
temp, and rechecked the clearance with a good go-no-go guage, and the
clearances were correct.  I will never burn my hands again.

I did not take your post to be a flame, so please do not misunderstand my
reply.  I simply wanted you, and the list to know that I do not just shoot
from the hip in my efforts to help.  I have been working on cars of all
makes and models for over 25 years, I collect classics and do ground-up
restorations including paint and body.  I drive Toyotas for their fine
engineering and extremely close tolerances.  As a matter of fact, some time
ago I posted my experiences in the disassembly and tune-up of a 77 Celica
automatic transmission valve body. In that case someone had dumped Dextron,
and who knows what else, in a tranny that was designed for Type 'F'.  (Yes,
the earlier Toy trannies get Type 'F', I was surprised too)  After that
valve body repair I flushed the fluid with the car idling and the line
pointed in a bucket.  That car is still shifting perfectly at almost 200,000
miles.

Running the tranny dry and actually putting torque to the clutches, as in
driving and trying to move the mass, will certainly result in damage.
Running the fluid a little low, at idle speed, for no more than a few
seconds, with a constant fresh supply of fluid that is room temp right out
of the bottle, should be just fine.  

The bottom line is, to each his own.  I didn't get really detailed in my
first explanation and that is my fault.  You folks don't know me all that
well, and I only post when I have something to say that may be of help or
relevance. 

You are right Darren, the 'right' way is to drop the pan, clean the pan,
clean the screen, adjust the bands, etc.  I do this as well when I am
performing a 60,000 mile type maintenance.  I suppose the 'right' way to
flush brake fluid is to remove each wheel cylinder and check for pitting and
the overall condition of the pistons and cups, but I still open the bleeder
and have at it.  I read my genuine Toyota Service Manual, talk to my buddy,
listen on this group, and then make my own decisions.  

Thank you for inciting me to clarify myself.

Ed Fisher

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