Question and thoughts on Transmission flushes

[Chris B.]

My 1997 Tahoe now has 104,000 miles on it. I bought it used. The auto transmission shifts great, smooth and solid, never slips! The guy I bought it from was a BMW mechanic and gave me maintenance recepts. He change the fluid and filter at 80,000. I had it 100% flushed at 99,000 miles and at 104,000 it is shifting great!

My question is could the flush I did have caused any harm that will still show up soon? A co-worker of mine said I should not have flushed it and guarantees that it will fail soon now with in 4,000 more miles.
I say BS as it had been 4,000+ miles sence the flush and the thing is shifting better then ever! How cold the flush done any harm and why is it taking so long to show up if anything was done???? Pleas tell me this guy does not know what he is talking about!

Thank for the help!

 

[Anthony]

Was 80k the first time he changed it? For a gm tranny thats kinda long. If it hasent failed yet it probably wont.
Ive heard of cases where people have never touched there trannys in over 100k and then decide to flush and the car gets stuck in the bay!
I think it will be fine.

 

[Ugly3]

Chris B. - A co-worker of mine said I should not have flushed it and guarantees that it will fail soon now with in 4,000 more miles.

Have your co-worker who "guarantees" your trans to fail put up $100 bet on it.

 

[kenw]

I have several mechanics who have stopped flushing for similar reasons. I trust these guys totally, altho I do not know the reasoning behind their new-found opinions. They don't go so far as to claim a definite shortening of the life, but all say with regular drain and fill it isn't needed.

 

[4.8 Silverado]

I have read posts where people have had problems on a badly neglected 4l60 tranny that was flushed . This model tranny has known weaknesses and will crap out even with regular maintenance.If its a 4l80 you stand a much better chance of not having any problems.

 

[Chris B.]

Thanks for the replys guys!

The only time I can say for sure was that it was changed at 80K with a new filter at that time as well.

When I did the 100% flush the shop used the Winn's machine and cleaner. Is this a good system?

 

[Ken2]

Many times folks flush their transmissions because the transmissions are exhibiting problems. The sick transmission fails after the flush and the flush gets the blame.

Some times a simple flush may stir up some crud in the transmission and upset the already poor operation. Again, the flush gets the blame.

Clean the transmission with Auto-Rx, refill with synthetic ATF, and don't worry.


Ken

 

[JohnBrowning]

In GM trucks if the transmission is going fail due to poor build quality or neglect then it is going to do it in less then 80,000 miles. Most of GM products have a silly 100,000 mile ATF change schedule. Mix that ATF OCI with towing in overdrive and over loading and you have a receope for freq. transmission failure.

I do not like people going so long before they change their ATF but you are probably fine. THeir is no problem with flushing a transmission. The problem is with neglecting a transmission. I am a big fan of Auto-RX in automatic transmissions! I am even bigger on not exceeding 24,000 miles with conventional or 50,000 miles with synthetic.

If people drained the pan once a year and refilled with fresh ATF most trany problems outside of poor build quality would be unheard of!

Again do not worry about you are fine. I have neveer had a flush or pan drop and top off do anything but help a transmission! HEard all the old wives tales but never seen it make things worse!

P.S. Some flushing outfits add harsh solvents to the ATF and these can be hard on already brittle or varnished seals.

 

[97tbird]

When I bought my 97 T-bird, it had 72k miles, and had a shuddering 3-4 shift. (famous for the 4R70W). I took it get the ATF changed, and the yellow "factory plug" was still in the pan, floating around in the dark brown, burnt fluid: the ATF has never been changed. Against the words of a lot of people, I had the dealership do a flush (they used Wynn's machines, too), and refilled with Mercon-V, and the shudder went away. I had it flushed again at about 85k miles. Now the car has 105k miles, and the tranny is still fine...time for another flush, though.

The downside of flushes is, they don't change the filter when they do a flush. So you actually have to ask them to do a pan-drop and filter change, and also a flush to get the ATF from the Torque converter out. I get my filter changed every other flush, I think that's OK. (Most places now don't want to do a traditional pan-drop and drain the torque converter by hand even if it has a coverter-drain plug; they lean more towards the flush)

 

[RF Overlord]

quote:

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Originally posted by JohnBrowning:
THeir is no problem with flushing a transmission. The problem is with neglecting a transmission.

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quote:

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Originally posted by JohnBrowning:
If people drained the pan once a year and refilled with fresh ATF most trany problems outside of poor build quality would be unheard of!

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^^^what JohnBrowning said^^^

quote:

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Originally posted by Ken2:
Many times folks flush their transmissions because the transmissions are exhibiting problems. The sick transmission fails after the flush and the flush gets the blame.

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^^^what Ken2 said^^^

 

[JMG]

I had a BG flush done on my Cr-V and it shifts like it never has. Smooth and cant even feel it.

I can see the point on not having a flush and I probably wont spend the moeny next time. I will just have the fluid changed.

 

[[email protected]]

Ive never had a trans flush performed on my 2002 Envoy (4L60E transmission) but I do know that when I dropped the pan and changed the fluid/filter it was the first time (at 65k miles). The pan was filthy and the magnet was basically a square of what looked like chocolate cake on the bottom of the pan, LOL. After cleaning that mess I refilled with quaker state dexron III. However the fluid was still kind of dirty since I only changed 5 qts of the 10+ qt capacity. My solution: I bought a hand siphon. 3 times now i have siphoned out 4-5 qts of fluid and refilled through the dipstick. It takes a few minutes, is totally clean, and now my fluid is a nice bright see-through red. My shifts are better, and Im confident I will get many more miles out of my 4L60E. My point: The stupid flush was $99 around here. For $7.99 for a hand siphon and $4.28 for 4 quarts of dexron III, even though I had to buy 4 four quart jugs, Im still way under that mark and accomplishing the same thing (slower, yes). I would rather do it this way than be one of the horror stories from the flushing machines.

 

[Chris B.]

quote:

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Originally posted by [email protected]:
Ive never had a trans flush performed on my 2002 Envoy (4L60E transmission) but I do know that when I dropped the pan and changed the fluid/filter it was the first time (at 65k miles). The pan was filthy and the magnet was basically a square of what looked like chocolate cake on the bottom of the pan, LOL. After cleaning that mess I refilled with quaker state dexron III. However the fluid was still kind of dirty since I only changed 5 qts of the 10+ qt capacity. My solution: I bought a hand siphon. 3 times now i have siphoned out 4-5 qts of fluid and refilled through the dipstick. It takes a few minutes, is totally clean, and now my fluid is a nice bright see-through red. My shifts are better, and Im confident I will get many more miles out of my 4L60E. My point: The stupid flush was $99 around here. For $7.99 for a hand siphon and $4.28 for 4 quarts of dexron III, even though I had to buy 4 four quart jugs, Im still way under that mark and accomplishing the same thing (slower, yes). I would rather do it this way than be one of the horror stories from the flushing machines.

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Good idea!

 

[ALS]

I just flushed the transmission in my 97 Volvo 960
yesterday. My dealer used a BG transmission flushing Machine to swap out the fluid. According to Volvo they are life time fills. Well at 66,800 miles the fluid was dirty, burnt, and a down right nasty brownish color.
As soon as the drain was opened you could smell it 5 ft away. The pan bottom and sides were coated with a gritty film that washed off easily. The four magnets although covered with this film had almost zero metallic particles stuck to them. I figure this film was caused by the fluid breaking down.
I don't care what they say, a transmission flushed every 30K is cheap compared to a $2000 rebuild. The previous owner followed the book and of course never serviced the transmission. It seemed to shift fine before the flush and I'm glad I changed out the fluid after seeing what was in the transmission. I filled it with Redline D4ATF so I have no worries for a few years. I figure spending $95 for fluid every 4 years is cheap insurance.
The automatic Aisin Warner (AW71) that was in my 1987 Volvo was serviced religiously every 30K miles. I pulled it out at 260K to swap for a manual transmission. The tech that bought it off me has at least 50K more on it in his car and it is still running fine.

[ February 12, 2005, 01:21 AM: Message edited by: ALS ]

 

[Islandvic]

If it was my Tahoe, I would do another pan drop at 110k mark. If your last pan drop was at 80k, then at 30k on the filter, it should be changed again. Plus you can inspect the magnet and clean up the goop.

"Flushes" have a bad rap because I have heard all are not equal.

The BG machine lets the trans pump do the work. Its a low pressure system that takes awhile, but doesn't force oil in or out at above normal spec pressure.

Some machines are called "power flushes" I think that runs the oil under the machine's pressure (bad).

Others are "reverse flush" that somehow runs the oil flow backwards and is supposed to clean the filter. I think that's bogus. Some dealers do it.

You may wantto add some LubeGuard. I forgot what color you would need. That is supposed to be one of the few additives that actually works,

One of my cars has a drain plug on the torque converter. With a pan drop and TQ drain, I drained 11.5 out of 14 qts in my back yard. I could have gotten the other 2.5 out, but I didn't disconnect the cooler lines.

Good luck.

 

[RF Overlord]

quote:

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Originally posted by ALS:
According to Volvo they are life time fills.

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Unfortunately, what most people don't understand is that "lifetime fill" really means for the lifetime of the WARRANTY, not the transmission...ALS's experience proves that.

 

[ALS]

I don't know if this will help some of you since it applies to Volvo's but I'll post it anyways.
Flushing the Aisian Warner Transmissions
From the Brickboard.com FAQ
7XX/940 Fluid Flush.
Rationale:
[Editor] If your car has sluggish shifting, especially when cold, or you would like to remove all dirt and old fluid from your transmission, consider a complete fluid flush instead of just draining and refilling the pan.
Procedure:
I recently changed the trans. fluid in our '92 940 using the cooler line disconnect technique. Here is the easiest way to do it:
Obtain either IPD's transmission flush hose or a clear vinyl or plastic tube (3/8 inch I.D.) about five feet long and three gallon milk jugs, calibrated with a permanent marker in quarts. Have at least your tranny capacity (approx 9 qts.) in new fluid on hand. 3/8 is a tight fit (heat it in water to get it on); 1/2 inch I.D. will require a clamp.
Drain all the oil from the transmission drain pan (2-3.5 qts depending on model).
Refill 2 qts into the filler tube.
Disconnect the transmission cooler return line at the radiator; it is the top line entering the top fitting at the radiator. Use a counterhold wrench and be careful you do not crack the fitting out of the radiator. Penetrating oil can help loosen threads.
Connect the clear plastic hose to the radiator fitting by pressing it on the threads. Fish it through over or through the grill and into to a gallon milk jug on the ground.
Turn on the engine. Fluid will start draining out of the tube into the jug. The fluid does not drain out all that fast - ~25 seconds for 2 qts - and stops when you stop the engine.
Watch the fill rate on the side of the jug and have a friend refill at the same rate into the filler tube. [Editor's Note: have a friend engage parking brake, apply the main brake, and place the transmission in "drive" for a minute to flush out other parts of the valve body and torque converter.]
After approximately nine quarts, you will notice fresh fluid flowing out of the hose. Stop here.
Button things up (do not overtighten the cooler line fitting), check final level, check for leaks, etc.
Everything worked very well - the only pitfall was that I ended up overfilling the trans. a bit (~3/4 qt) - I think I must have been a little off every time I estimated I had drained 2 qts. So finally I had to pump all that out of the filler tube while checking the level - a bit of a hassle but not too bad. [Tip: if you overfill, just unscrew the pan bolt slightly and hold it while the fluid drips out to the quantity required. Messy but easy.]

The BG machine did almost exactly what the FAQ instructions state. The only difference is it measures the fluid exactly ounce for ounce. It takes out 8.2 quarts of used fluid and it is replaced with 8.2 quarts new fluid.
All it was is a large can with a rubber bladder in it. You fill the bladder with the fresh oil and as it is emptied into the transmission the area under it fills with the used fluid. The machine only regulates the amount going in as fast as it is coming out. If I had a few Volvos with automatics I would build my own unit. Heck all I would need is the hose fittings and hoses to connect to the Radiator. Then make a can system that was gravity fed with a can underneath to collect the old fluid. Put a inline valve on the top hose to stop the flow if need be. I figure two clear 3 gallon plastic lexan containers Marked off in 1/2 quart increaments on a 3 ft high rack would be all you would need. Put a clear glass or plastic tube in the end section of the return hose just before the collection container on the bottom to monitor the color of the fluid coming out. I figure less than $100 max to build it.

 

[wtd]

I'm leery of tranny flushes because of the same info that was told to you. My 98 chevy truck's 4L60E has a drainplug in the pan and I just drain and refill about every other oil change. I know that this is overkill but this tranny has some known weaknesses so I want to give it all of the advantage I can. This way I always have fresh fluid in it. Soon I'm going to change the filter since its been about 40,000 miles since that was done. Truck has 76,800 miles on it and still shifts good.

Wayne

 

[[email protected]]

Hey! I wish my 2002 Envoy had a drain plug in the trans pan

hehe Ive been looking around to "install" one. Apparently they sell kits for drain plugs. I siphoned out 4-5 more quarts of trans fluid today on the Envoy. Now its allllmmost where I want it (the fluid). I actually bought a pan on Ebay with a drain plug already in it, but apparently my Envoy's trans filter is deeper than usual 4L60E's and the pan I bought wouldnt fit. It must be the "professional heavy duty towing package" that the truck came with?

 

[wtd]

My truck didn't originally have a drainplug in the tranny pan. I bought a pan from an online dealer for a 99 and up silverado that had a factory drainplug. My truck did come with the deep pan though.

You should be able to buy a filter kit that would allow the pan you bought off of ebay to work. As far as I know, all of the 4L60E trannys are pretty much the same. Was the pan you bought off of ebay flat or was it deeper on one end than the other? What does the pan on your Envoy look like? Does it look like the one you bought on ebay? You could just order a deep pan with drainplug for a 2002 Silverado and get the deep filter kit for the same. The pans are not that much.

Wayne