Transmission filter and oil 100k do or dont? [Archive] - Forum


View Full Version : Transmission filter and oil 100k do or dont?

11-17-2005, 04:59 AM
Needing some advise, just turned 100k on my problems but
I need some help deciding weather to or not to change the tranny oil
and filter. shifts are all fine, only a lite slam into Drive when cold but it's
done that for sense I purchased the car nearly 2 years ago.
should I? flush and DEX III just DEX III and no flush? flush or no flush
and add Mobil 1 syn ATF?
do nothing at all?
any suggestions would be great.
also planning to sell and get a new model GAGT this comming spring,
thx in advance.

ive taken care of and babied my car sense I have owned it.
water pump.
serpentine belt with a gator.
mobil 1 syn and filter, still no leaks.
AC delco factor plugs.
DR Speed WAI.
radiator flush and fill.
New PowerSlot rotors and pads form and brake flush n fill.
driver side motor assy replaced, already needs another.......
and recently replaced fuel filter.

11-17-2005, 01:27 PM
I have had a new ac delco filter but it did not come with a new rubber gaskit, with this many miles should I go ahead and get a new one?
I'm planning to go ahead and change the fluid and filter this weekend unless
anyone thinks I should leave it as is sense i'm having no problems.
i'm unsure what to do from reading conflecting post saying flushing or changing
the fluid on high mile cars soon developed problems.
other post say do it if the cars been taken care of and not driven to hard.
thing is even though ive had no problems yet, I don't beleave the fluid or
filter have ever been changed by the prev owner.
I have read about smoother shifts using mobil 1 atf and would prefur to replace the old fluid with that but still unsure.

Mike Jung
11-17-2005, 02:42 PM

If you are going to sell the car in the spring, why bother changing the ATF.
(Unless the tranny is shifting abnormally.)

If you are going to change the ATF.
I would just do the ATF pan drop & refill method; & not flush out it.
I would change the filter & gasket though.
& use the regular GM ATF fluid.

11-18-2005, 09:34 AM
thx for reply mike,
ive looked over about all the post I can find on this subject, many post
but not much information on what to do for high miles.
would be nice if there was something in the How Too section
about Trans fluid and filter change.
what you said sounds good mike, this weekend i'll pick up a new gasket
for the pan and just drop the pan and put the new filter and fluid in.
hopefully it will be happy and freshend up a little. I wont flush but
even with just 6-7 quarts of newATF fluid mixed in the system it should
be better than doing nothing at all right?

just a couple questions,
how to go about changing the filter? do I just pull or any clips or certain
way to remove it and install the new one?

and as for ATF fluid, my local gm dealership would not sell me gm atf fluid
so i'm gonna having to find something as close to the gm stuff as possible
at local stores like advance auto, autozone, wallmart and need suggestion of
what to get simuler to the gm stuff?
I want to go ahead and do this now because I do really like my car and might
hold off getting a newer model another year.

Mike Jung
11-18-2005, 02:53 PM
Sorry, I have never personally done a ATF change (but paid a dealer do it, when changing an axle shaft seal under warranty).

See GrandAmGuru post in thread: Transmission Fluid Change ( in the pan.
Which is about 7-US Quarts

See mfuller post for checking ATF level & fluid colour/condition in thread:

That is weird that a GM dealer won't sell you ATF fluid.
Try another GM dealer maybe ?
Or an authorized AC Delco Wholesaler that sells to the public ?
Or go to a auto parts store & buy: ATF that is Dexron III type.

Haynes Repair manual says about the filter (after the pan is off):
Pull the transaxle filter straight down & out of the transaxle - there are no fasteners.
Pry out the old seal, be careful not to damage the aluminum housing.
Push a new filter seal fully into its bore, then install the new filter.

Note: Don't lose the magnet when taking off the ATF pan.