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auto tranny flush


daswede's Avatar
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09-18-04, 03:45 PM   #1  
auto tranny flush

I am wondering about the 'power flush' method vs. the 'old' way of changing tranny fluid. I question the power flush method,but many dealerships do this all the time.

 
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09-18-04, 06:00 PM   #2  
It's much better, the average FWD trans holds 8 qts. You drain the pan and get about 2 qts, drop the pan you get 2.5 qts maybe 3.

The rest is in the convertor. The Power flush will exchange almost 100% of the fluid. By just draining your mixing 3 new with 5 old.

 
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09-19-04, 06:22 AM   #3  
Thanks toyotaman for your reponce.
Another question is,what about the filter? Doesn't it need to be changed to?

 
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09-19-04, 09:04 AM   #4  
Well if you have a true filter as opposed to a screen then that would still be required to be changed.

But as I stated, dropping the pan to replace the filter still leaves approx 5 qts of old fluid in there.

Going back there were some models that had a drain on the convertor that got most of the fluid out but by and far those are gone today.

Even draining the convertor didn't flush the old fluid out of the lines and cooler the way the flush machines do today.

 
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09-19-04, 10:29 AM   #5  
Thanks for your explaination

 
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09-20-04, 05:22 AM   #6  
transman618
Flush

Unless the fluid is contaminated, a pan drop and filter change is sufficient. If you insist on the flush just make sure the pan is dropped and cleaned and the filter changed BEFORE you flush. It is very important that the debris in the pan is examined. Also, do not take it to one of those fast lube places to be serviced. Let a qualified transmission man service it. Try to get yourself on a schedule for servicing the trans every 25k.


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09-20-04, 06:18 AM   #7  
But what about the fluid quality? I have a 2000 Plymouth Voyager, a model with known tranny problems. The fluid I am told to use is Chrysler ATF+4 (which is a dealer only product, and expensive). I've asked these "Flush" type places what fluid they use and I am told it is a "universal" type - which, if true, can't be good for a car which requires a special fluid.

What fluid really is used in these flush machines, how do you make sure they use the correct fluid and is the "universal" type fluid really OK?

 
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09-20-04, 07:53 AM   #8  
I've asked these "Flush" type places what fluid they use and I am told it is a "universal" type - which, if true, can't be good for a car which requires a special fluid.
A dealer with a flush machine will use the correct fluid, I would also think a trans shop will also use the correct fluid.

 
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09-20-04, 10:31 AM   #9  
sicando
Automatic or Manual

Does all this info pertain to a manual transmission as well as automatic? Also, if you do it yourself,,,how will you know how much was drained out and how much to add if it all does not come out on first drain? Do you fill it till the fill plug starts to overflow? Do you need to measure the amount in the drain pan and put like amount back in? Should you warm up the engine/tranny to running temp. before you drain??? Thanks for you replies.

 
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09-20-04, 11:30 AM   #10  
I guess i kinda opened a 'can o' worms' of sorts. all good questions and answers. While i read these posts i thought of another question concerning auto transmissions. If it has been been part of the routine of flushing and refilling the tranny to replace the filter,how is it that this is not mentioned to do at the dealers/trans. shops? briefly, It was always part of auto tran. service to drop the pan,change the gasket,replace the filter and replace the pan and fill with new fluid. Does the filter not need to be replaced to?
I have a 5 yr. old ford and a brand new GMC Sierra. when i'm at the dealers
they offer "trans . service specials" which only mention flush and fill.

 
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09-20-04, 12:24 PM   #11  
There are alot of trans out that have no filter, only a screen that you wouldn't change. Thats why they rec flush and fill.

By just dropping the pan you are replacing less than half of the total fluid.

Assuming the fluid is clean doesn't mean anything. There are additives in the fluid that are used up. Its much better to replace as much of the fluid as possible. There are things in the fluid like anti foaming agents, friction modifiers, anti corrosive agents, etc.

 
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09-20-04, 03:13 PM   #12  
sicando

To answer your question no: Flushing machines don't apply to manuel trans.

Just drain out and refill till it just runs out of the fill plug. BTW you will notice smoother shifting if you use synthetic gear lube

 
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09-20-04, 04:22 PM   #13  
Toyotaman

I trust your judgement on the subject from past replys I am pondering the use of synthetic in my 2003 Toyota as the gear oil.Should I wait till the warranty is up?Does Toyota endorse synthetic gear oil in there gear boxes?
I do not want to cause any doubt just in case I need a warranty claim from them.
I really do not think my Toyota will have problems of that sort but you never know.


Last edited by michael van; 09-20-04 at 04:23 PM. Reason: spelling
 
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09-20-04, 04:55 PM   #14  
As long as it mets the minimum requirements your ok. Which I'm sure it will.

I wouldn't wait, the warranty is 60k on the powertrain.

It's funny the factory reps recommend synthetic for poor shifting complaints but will not pay for it under warranty.

BTW how did the AC go?

 
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09-20-04, 05:36 PM   #15  
Thank you

Thank you very much toyotaman But I just changed fluid at 30 thousand miles with Castrol gear oil so next time it comes around to change I will look into the syntetic oils.

 
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09-21-04, 05:26 AM   #16  
Thanks to all for the info. I learned something new today.

 
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09-21-04, 02:21 PM   #17  
As a side note to those who are interested Gm does not want the flushes done as failures have resulted from them being done.This is because Gm uses a filter not a screen and particles can clog the filter after the flush is done.A letter was sent to dealers advising against it.If you also change the filter you would most likely be fine.

 
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09-22-04, 05:28 PM   #18  
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As far as ATF quality, I would only use what the manufacturer specifys. When these shops tell you they use a "universal" fluid, what they are saying is that they use Dexron fluid with a friction modifier additive. They do this because it is cheaper than using what the manufacturer calls for. I would make them use the proper fluid.

As far as changing the filter. On transmissions that have them, the pan should always be dropped FIRST and the filter changed BEFORE flushing. Properly servicing a transmission means dropping the pan so the debris on the bottom of the pan can be examined. This is the only way for a transmission tech to be able to tell whether there is a problem coming up around the corner. What I usually say is, palm readers read palms, transmission techs read pans. By looking at the debris in the bottom of the pan, I can tell what is coming up in the future for this trans. Brass, aluminum, or steel shavings or clutch material in the pan means something is wrong and it needs to be brought to the attention of the owner. This covers the technician too just in case the trans goes out after servicing. Some transmissions. Honda and Mitsubishi, for example, have transmissions which do not have pans. Honda has two piece aluminum cases which have to be removed and disassembled to access the filter. I would never flush one of these transmissions. I usually recommend to my customers, a pan drop and filter change every 25k.


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09-22-04, 08:38 PM   #19  
Reading Palms

Transman, you are bringing tears to my eyes
I wish GA wasn't so far away from CT
I would go or send anyone to you after that last post
Reading the pan...Oh man...
We live in a quickie-flush world
It's nice to hear from a Trans Man

 
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