(SPECIAL THANKS TO GREG
BOEHM, OF VALLEY TRANSMISSION IN EL CAJON, CALIFORNIA, FOR THE
EXPERT ADVICE)
It's not uncommon for the owner of a full-sized truck to get
150,000 to 200,000 or more miles out of a well-maintained V-8
engine. But, more often than not, well before the engine gets
tired, the automatic trans dies. This is avoidable, if you simply
do some basic auto trans maintenance.
You know that you should change your engine oil every
3,000 miles or so to ensure long life. Why then, do we take the
trans for granted? Once a year. I service my truck trans and have
been rewarded with trouble- free service. In fact, my old Ford F-
250 has almost 200,000 miles on the engine and the trans has never
been rebuilt! It's still working smooth and slick, in spite of
towing some heavy duty loads over the years.
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With your vehicle safely in the air, loosen the bolts on the
trans drain pan. Here's a tip. The Ford E4OD we're working on here
has a torque converter drain plug, which will dump about 5 quarts
of ATF before dropping the pan, making the job a bit less
messy.
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With the bolts removed tilt the pan forward and drain the
fluid into a catch pan.
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The secret? Every 12 months, I drop the trans pan,
drain the trans fluid and check the pan for any tell-tale residue.
Then a new trans filter is installed, and I adjust the bands. Sure,
it's a messy job and you're going to have to grope around under
your vehicle, but the pay-off will be extended trans life. Here's
how to do the job:
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For the intelligence impaired, we offer the
following warning: When you put your rig up in the air, make sure
you put hefty jack stands under the frame rails so the dumb thing
doesn't fall down and crush you like a grape. While you're at it,
make sure the trans fluid is not hot.
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Get a drain pan - preferably a big one - and
place it under the trans.
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Loosen all the trans pan bolts until you can
turn them with your fingers. Then remove the bolts from the front
part of the pan and start tilting the pan down so the fluid has a
path. If you can find a second set of hands under your rig, so much
the better. This way, you can remove the bolts and your buddy can
tilt the pan forward to drain the ATF with minimum splashing and
dripping.
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Remove the pan completely and inspect what's
left in the bottom. If the ATF is clean, you're lucky.
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If there's a bunch of crud in the bottom of
the pan, chances are you have some real trouble brewing, and you
should bolt it back up and take it to a savvy shop, and find what
caused the grief.
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If your trans fluid is clean, but has a heavy
burnt smell, get thee unto a
trans shop.
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If you find aluminum type powder in the pan,
you've got serious problems!
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Next, remove the trans filter. Some filters
are held in by a bunch of small
bolts, while others are locked in place by a single bolt, and
others are simply pressed into place and held there by a grommet,
like the E4OD shown in the photos.
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If you have a filter with a metal screen, it
can be reused if there's no crud in the pan, and no debris in the
metal screen, even though you're always better off playing it safe
and installing a new filter.
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If you find metal particles on the screen, or
in the filter, you've parts starting to fail inside.
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Do not re-use the paper or element type
filters, no matter how clean they look.
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Clean the pan thoroughly and remove the old
gasket.
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If the bolt holes are misshapen due to
over-torquing. place the pan
edges on a metal table and lightly hammer the metal flat. Easy does
it with the hammering.
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Adjust the bands, if applicable. Most of the
GM turbo transmissions have no band adjustment provision, but the
Ford and Torqueflite trannies do. Refer to your manual - or call
your dealer - for torque specs. For example, the Ford A4LD trans
has two bands that adjust: an overdrive and intermediate (2nd gear)
band. To adjust these, back off the jam nut, screw in the adjusting
bolt to 10 foot pounds, then back off 1 3/4 turns. Tighten the jam
nuts back up, taking care not to move the adjuster bolt, and you've
done what a savvy trans man can do, all by yourself!
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Now fill up the trans with the recommended ATF
and check the level. Make sure you get the trans warm before you
accept the reading on the stick. I like to get a basic reading,
drive the vehicle for a mile or two, then recheck the reading.
Always check the fluid level with the engine running and the trans
in PARK.
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Do a visual check to see if you have any leaks
from the pan or the new gasket.
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Remove the trans filter. In this E4OD, it just pops out. On
others, bolts hold it in place.
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Surprise! We found what caused this trans to go bad. When the
trans was last serviced the original holding grommet was left in,
and when the new filter/grommet was installed, the filter sat too
low in the drain pan, and badly restricted the fluid
flow.
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Check the trans pan for crud. We found a lot of gunk in this
particular pan.
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Also check the fluid for aluminum particles. With Ford
products, any aluminum powder is bad news. With GM products, some
aluminum powder is normal.
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The old smell test lets you know if the trans fluid has run
hot. A burnt, foul smell is a dead
giveaway.
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Remove the old pan gasket and do not reuse
it.
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Scrape the pan clean of any remaining gasket or cement. Take
care not to gouge the metal.
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Wash the pan until it's clean. Do not wipe the inside of the
pan with a rag without air blowing it clean, a little bit of lint
can clog things up inside the trans.
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Lightly hammer any bent bolt holes on the pan flat for a good
seal.
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Install a new trans filter. Mounting instructions usually
come with each filter.
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Never even think
about re-using an element type filter, such as this GM
product.
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Carefully check
the screen on a metal filter for large particles. In an emergency,
this type of filter can be re-used.
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InInstall a fresh pan gasket (Valley Trans says not to use
gasket cement.) Carefully install the pan back on the trans using
proper torque specs from the
manufacturers.
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Adjust the band(s) on your trans. On the C6 shown here, there's one
band adjustment for 2nd (intermediate) gear. Loosen the jam nut,
torque the adjuster down
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After filling with the correct type and amount of
ATF (again, check your manual), do a quick check for fluid
level.
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After driving the
vehicle around for afew minutes. do a final check with the engine
running and the trans in PARK. Now, repeat this process every year
or so, and you'll have a reliable, long lasting
tranny.
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CAN YOU AFFORD TO TAKE CHANCES?
Auto trans fluid is about a buck per quart, and trans
filters range from $6 for some GM models, to the mid $20s for Ford
products. Rebuilding a full-sized auto transmission can cost you
anywhere from $700 to several thousand.
Like Greg Boehm of Valley Trans told us: 'If
people changed their own trans fluid yearly, I'd be out of
business!"
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