Transmission Flush - Do it myself?


Old 09-30-04, 05:19 PM
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Transmission Flush - Do it myself?

My wife took our '99 Pontiac Grand Am (GT, automatic, 3.4L, V6) to get an oil change (I can hardly buy the oil and filter for as cheap as they can do it, and I am a procrastinator at heart). They told her that GM suggests a trasmission fluid flush after 60,000 miles, we are almost at 70,000. She said the tech mentioned something about a sealed system. It costs $80! Is this reasonable and/or worth it? It sounds high to me, but I have never had a vehicle new enough to care about a detail like that before (you can imagine my previous cars). Is this something that I can do myself one weekend with just my basic garage tools?
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Old 09-30-04, 05:37 PM
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Not sure about the sealed system, but was curious to see how satisfied you are with the Grand Am. I had the same exact vehicle as you do and had nothing but trouble with it from the day I took it off the dealer's lot.

Old 09-30-04, 05:58 PM
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You are just trying to jynx me aren't you? [knock on wood] Very pleased. Biggest problem I have had to date is a $1725 raccoon.
Old 09-30-04, 07:24 PM
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Unless your car is used in heavy service - taxi, police car, etc, most manufacturers say to leave it alone. The lube places and some dealers have found quick, big, bucks in promoting tranny flushes. I've run about every vehicle I've owned well past 120K on the original fluid without a problem.
Some forum members will probably respond to the contrary, but that's my view.
Old 09-30-04, 07:44 PM
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Check the owners manual and see if changing the fluid is recomended at xxxxx miles. Flushing is not necessary. You should be able to remove the transmission pan, change the filter and the fluid. I think what they meant by sealed is that there is probably not a drain plug in the trans. pan.

When there is a place to put one I always put in a drain plug. You can buy a drain plug at the auto store that requires drilling a 1/2" hole in the pan. It is just a 1/2" bolt & nut with a hole drilled in the center for an 1/8" pipe plug. Some use a small bolt with a rubber washer for a drain plug. I do not like those. You want it tight so it will not come out but then you squish the rubber and it leaks. If you can't find the 1/8" pipe plug type, B&M transmission products makes one with the 1/8" pipe plug. Just watch where you put it so it does not hit anything inside the transmission and don't put it where you will rip it off if you run over something. Then it is easy to drain the fluid & replace it occasionally. You do not need to change the filter a 2nd time. Fresh fluid will help promote a longer trans, life.

Yes cars can go 100,000 + miles on the original fluid but the additives in the fluid wear out or disipate over time just like the additives in motor oil. Your transmission has a much better chance of a long life if the fluid is changed frequently. This is especially important for heavy use such as trailer pulling.
Old 09-30-04, 08:03 PM
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To do a tranny flush would require, at minimum, an $89 hand pump fluid exchanger
By sealed do they mean no dipstick?
The GM word on fluid changes will be in the owners manual
Who recommended the flush?
GM dealer or Qwik-e-loob?

goldstar does have a point, inasmuchas it is quick easy money for Qwik-e-loob or even Dealers to sell an $80-$179 flush that needs a $89 pump and a...well a body to perform
And also if you came to me with a 120K vehicle and the manufacturer said change it @ 30K, and you had no problems and the fluid looked good, I would not want to flush your system because at that point, it may do more harm than good
Many people do not realize what the manufacturer will consider heavy service
Towing a 5th wheel, living in Woodford VT. or Flasher ND. would all be considered HD sevice by the manufacturer
Old 09-30-04, 08:09 PM
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As per car nut "your transmission has a much better much better chance of a long life if the fluid is changed frequently"
Old 09-30-04, 09:38 PM
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slickshift...just read your post on changing fluid at 30K. Just curious but is it possible to change the fluid too often? Any idea why manufacturers don't put a drain plug in the trans. pan? I don't get it.
Old 09-30-04, 10:09 PM
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30K was an example, but not unusual in the day (older trans)
Drain plug in the trans...OH YEAH...that would make sense!!! Right on!!!
Pull the pan??? what a mess!!!
But ????
I have no idea why mfg. would say "chg it @ 3K-6K-etc." w/o a good way to check it
CYA? but still keepem cheap?
Drain plug in the pan seems logical but...?
I really don't get it either but...?
If you start from day one, you cannot change tranny fluid too often
Old 10-01-04, 04:03 PM
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If you don't know how to do it, leave it alone. Or have a professional handle the work.

Sealed system, referred to a system without dipstick. Usually manufactured by ZF. They also has several models that has life long fluid (never have to flush transmission) or long life fluid (flush every 80K) Consult your manual to find one which one you have.
Old 10-02-04, 04:12 AM
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Gm does not recommend transmission flushes because of filter design.Your fluid should be changed at 50k miles.You can check the fluid by removing the plug on the side of the trans with the engine running and sitting level on a hoist or 4 jackstands.Your car will hold 6.9 quarts of fluid with a pan removal and filter change.
Old 10-02-04, 05:36 AM
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And don't worry about changing fluid too often, We do our wreckers every 10k miles with new filter every other change. The 4L80E in my truck went over 300,000 miles before overhaul. My wife's Camry has about 170k miles on it on 25k changes and I've cleaned the screen once. I wouldn't pay extra for a "flush"; regular service is the key.
Old 10-02-04, 07:27 AM
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Thanks for everyone's insight!
Old 10-02-04, 06:37 PM
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I have to disagree with you guys on the flushing. It's the best thing you can do for that transmission, provided it's done at regular intervals. You can't do it too often and you can't hurt it by merely flushing. The equipment applies no outside forces to the system. It simply lets the vehicle pump it's own fluid out while replacing it with fresh fluid. Fluid gets burnt, dirty and contaminated. 30K is a very good interval to use. Just don't wait too long and start late in the cars life. That will bring on problems. The average cost is usually around $90 to $120. That reflects the approx. 16qts of fluid, the equipment and one hour of the techs's time.
Old 10-05-04, 03:51 PM
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Desi you may disagree but I read the letter sent to GM dealers to the parts manager,service manager and technicians repairing GM transmissions.GM says it is not recommended.GM has inspected failed transmissions that were root caused to plugged filters following a transmission flush.GM does not use a screen type filter and it will not be cleaned during a flush.Most companies add a cleaning chemical prior to the flush to remove varnish and other buildups as well.This causes the filter to clog and then the trans fails.

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