# AT flushing?



## PasoRoblesJimmy (Aug 20, 2013)

Some people seem to be obsessed with it. Is automatic transmission flushing worthwhile, a pack, or is it a rip-off?

If one can achieve over 200K miles on several vehicles without an AT failure without an AT flush, why bother?


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## Walt41 (Aug 20, 2013)

I drop the pan and change the screen on my older vehicles once a year, cheap insurance and you can usually spot a problem before you are SOL on the side of the highway, on newer vehicles you can hook em up to a flush machine and get similar results. I stay away from additives and just opt for a fluid change. On high milers that have not been serviced it is a crapshoot because some builders will tell you that a flush might dislodge particles that might cause problems, never had that happen to me personally but there are enough stories out there that it could have happened.


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## PasoRoblesJimmy (Aug 20, 2013)

A tranny flush isn't going to fix, rebuild or overhall a worn-out, high-mileage transmission.

A late friend, the owner of a transmission shop, advised me to drop the pan, drain the fluid, inspect the bottom of the pan for particles of metal and replace the filter once per year. If I do that, I will never have a tranny failure.

Every factory service manual that I've seen recommends normal service only and has no mention of tranny flushing.

Makes me suspicious that auto repair shops, not manufacturers, are recommending tranny flushing.


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## lone wolf (Aug 20, 2013)

PasoRoblesJimmy said:


> A tranny flush isn't going to fix, rebuild or overhall a worn-out, high-mileage transmission.
> 
> A late friend, the owner of a transmission shop, advised me to drop the pan, drain the fluid, inspect the bottom of the pan for particles of metal and replace the filter once per year. If I do that, I will never have a tranny failure.
> 
> ...



How many miles on it? Was it ever changed?


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## PasoRoblesJimmy (Aug 20, 2013)

lone wolf said:


> How many miles on it? Was it ever changed?



Same thing for auto air conditioning. Repair shops want to charge big bucks to flush the refrigerant, replace the receiver-driver, replace the expansion orifice and add a filter when a failed AC compressor is replaced. 

After an AC compressor is replaced, the factory shop manuals for both of my GM vehicles say to fill the compressor with refrigerant oil, evacuate and refill the refrigerant and leave everything else alone. FYI, the receiver-driver has a filter already built into it.


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## lone wolf (Aug 20, 2013)

If you change it 3 times in a day or two it gets all the dirty oil out of the converter be sure to use the exact oil it calls for.


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## treesmith (Mar 4, 2014)

I did my falcon 4.0, when I bought it it had not been done since new so approx 240,000 miles. Gear change was chunky. It took me 20 litres of Ford atf to flush it through to clean fluid, cleaned all the pan and filter. It's been beautiful since


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## PasoRoblesJimmy (Mar 4, 2014)

treesmith said:


> I did my falcon 4.0, when I bought it it had not been done since new so approx 240,000 miles. Gear change was chunky. It took me 20 litres of Ford atf to flush it through to clean fluid, cleaned all the pan and filter. It's been beautiful since



Its much better to service your AT at least once per year so crap doesn't gum up the valve body in the first place.

The Ford Falcoon and Mercury Comet were pieces of crap no matter what was done to them. When you cross a Volvo with a Comet, you get a Vomit.


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## Mike-M (Mar 4, 2014)

I flush on low mileage cars only, which I dont have any anyway. On an old tranny, that **** in there may be the only thing keeping it going. 

Fluid, screen, no flush.


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## Knobby57 (Mar 4, 2014)

PasoRoblesJimmy said:


> Same thing for auto air conditioning. Repair shops want to charge big bucks to flush the refrigerant, replace the receiver-driver, replace the expansion orifice and add a filter when a failed AC compressor is replaced.
> 
> After an AC compressor is replaced, the factory shop manuals for both of my GM vehicles say to fill the compressor with refrigerant oil, evacuate and refill the refrigerant and leave everything else alone. FYI, the receiver-driver has a filter already built into it.




The filter in the drier catches any loose partials in the refrigerant and can clog or come apart with will trash your ac system it's good insurance to change the drier if you have any internal compressor failure or if your system was empty for a while. On another note r134a never goes bad on its own ever!! But it can be contaminated by improper recharging 


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## Deleted member 83629 (Mar 4, 2014)

i change fluid and filter yearly and have never had a problem with any of my truck either auto or manual. flush seems like a good idea but it wont help worn trannys. and plus fluid flushes are very expensive ( well they are here at 140 each!! ) .


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## Heilman181 (Mar 4, 2014)

PasoRoblesJimmy said:


> Same thing for auto air conditioning. Repair shops want to charge big bucks to flush the refrigerant, replace the receiver-driver, replace the expansion orifice and add a filter when a failed AC compressor is replaced.
> 
> After an AC compressor is replaced, the factory shop manuals for both of my GM vehicles say to fill the compressor with refrigerant oil, evacuate and refill the refrigerant and leave everything else alone. FYI, the receiver-driver has a filter already built into it.



Most of that is dictated by the manufacturers otherwise the warrantee is voided.


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## Heilman181 (Mar 4, 2014)

PasoRoblesJimmy said:


> A tranny flush isn't going to fix, rebuild or overhall a worn-out, high-mileage transmission.
> 
> A late friend, the owner of a transmission shop, advised me to drop the pan, drain the fluid, inspect the bottom of the pan for particles of metal and replace the filter once per year. If I do that, I will never have a tranny failure.
> 
> ...



It all depends on the vehicle. Some are damn near impossible to drop the pan and change the filter. It depends on what year, what fluid, what is the vehicle used for, etc....

I don't know about changing it EVERY year, but I would say every 40,000 - 50,000 miles (which would be 2 years in my case).


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## blades (Mar 6, 2014)

Hard use/ extreme temp conditions every 15-20k, filter fluid, general purpose 30-40k. If your unit does not have a tranny cooler, add one, cheap insurance.


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## treesmith (Mar 6, 2014)

I did a lot of research on transmissions and fluid flush/maintenance when I bought my falcon as it was my first auto, I came to the conclusion that manufacturers are either idiots or deliberately mislead customers. Some makers state filled for life with no maintenance which is complete rubbish, my falcon doesn't even have a trans dipstick. A new transmission can get away with just dropping the pan and filter, a second hand with 150,000+ should have the pan off and cleaned, a complete flush till it comes out clean and new filters. There's a lot of fluid in the system especially with a cooler. Mine came out the colour of used engine oil and took 20 litres to come through red. Change the fluid and it'll last, don't and it'll go bang soon enough


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## blades (Mar 6, 2014)

Sometimes even with proper maintenance things still go south do to design. I know of a couple AT out there that will last only about 100k anything past the is on borrowed time., no fault of owners, design life expectancy.


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## lone wolf (Mar 6, 2014)

blades said:


> Sometimes even with proper maintenance things still go south do to design. I know of a couple AT out there that will last only about 100k anything past the is on borrowed time., no fault of owners, design life expectancy.


Which ones are those?


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## Shagbark (Mar 7, 2014)

Do your research on the specific trans you have. I have a 5R110 automatic and there is no easy way to flush it. No torque converter drain plug. It takes very specific Ford spec fluid and there are horror stories about flush and fluid related failures. I chose to perform the change myself and followed a procedure outlined on a popular website - 21qts of expensive fluid later, a filter, pan clean out and a day of my life later, I was done.


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## Heilman181 (Mar 7, 2014)

Shagbark said:


> Do your research on the specific trans you have. I have a 5R110 automatic and there is no easy way to flush it. No torque converter drain plug. It takes very specific Ford spec fluid and there are horror stories about flush and fluid related failures. I chose to perform the change myself and followed a procedure outlined on a popular website - 21qts of expensive fluid later, a filter, pan clean out and a day of my life later, I was done.



So everything is Super Duty except for the transmission?


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## blades (Mar 22, 2014)

F150 from at least 97 up til about 2003, Ford used the smallest of the 3 trannies. in these. rear bearing is only splash lubricated and the overdrive bands are about 100k life span in combined driving. I think it was the 4r100( not sure on that #) in the larger trucks that 10 cent c-clip would give up and wipe ya out.


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## lone wolf (Mar 22, 2014)

blades said:


> F150 from at least 97 up til about 2003, Ford used the smallest of the 3 trannies. in these. rear bearing is only splash lubricated and the overdrive bands are about 100k life span in combined driving. I think it was the 4r100( not sure on that #) in the larger trucks that 10 cent c-clip would give up and wipe ya out.


I have a 97 F150 with over 200K on it.


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## olyman (Mar 22, 2014)

Heilman181 said:


> It all depends on the vehicle. Some are damn near impossible to drop the pan and change the filter. It depends on what year, what fluid, what is the vehicle used for, etc....
> 
> I don't know about changing it EVERY year, but I would say every 40,000 - 50,000 miles (which would be 2 years in my case).


 new ones are near impossible to cbange....


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## olyman (Mar 22, 2014)

and also..DO NOT, flush your fluid!!! you will dislodge all metal particles!!! then all this will be floating everywhere!! esp in the valve body!!! just change the filter,,and what fluid it needs....


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## greendohn (Mar 22, 2014)

I had the cherokee flushed at about 100k and have changed it a time, maybe two since then with filter,,clock is ticking 190k plus.
Pulled a cooling line off the dodge, brush busting and pumped a bunch out, did a roadside re-fill of 5 quarts, in the dark at about 10 degrees outside, still wasn't full, had a load of wood on it, got me home. Another 4 quarts later, , it was full again..have changed filter/fluid a couple times since then because I work it pretty hard and once to adjust the reverse band this past fall, which worked wonders!!
I think all fluids break down and need serviced. I am a fan of synthetics.
The flushing deal is supposed to remove tarnishes and sech,,I dunno...


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## Heilman181 (Mar 22, 2014)

Dodge transmissions typically generate a lot of heat. That is why most of the newer Dodges recommend fluid change every 30,000 miles. 

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## Homelite410 (Mar 23, 2014)

olyman said:


> and also..DO NOT, flush your fluid!!! you will dislodge all metal particles!!! then all this will be floating everywhere!! esp in the valve body!!! just change the filter,,and what fluid it needs....


No flush! I have always did a fluid exchange where the machine has an equalizing chamber of old and new fluid. We dis-connect the cooler line and hook up the machine. Start the engine and it uses the converter to exchange the fluid. Simply run the engine til both lines are same color and then change the filter!!


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## mopar3 (Mar 23, 2014)

I have been doing BG transmission flush at work on Chrysler products for years now. We have never seen any problems related to a flush being done. I have seen people come in with the wrong fluid used at other shops. This usually causes a shudder from the torque converter clutch. Older transmissions used more bushings and thrust washers so wear material usually found in the pan and on the magnet. The new trans are mostly all roller type bearings and do not have as much friction or wear. Trans fluids have also improved greatly over the years. I noticed a big difference in wear on the parts when doing overhauls once we went to ATF+4. If a flush kills your tranny it was on its way out already.


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## PasoRoblesJimmy (Mar 24, 2014)

lone wolf said:


> Which ones are those?



The 4-speed OD AT used in Dodge Caravans is notorious for failing at about 150K miles. The AT in the 1996 Dodge Caravan that I owned was starting to erratically jump back and forth between gears at 140K miles, so I sold it. IMO, almost everything on that Dodge Caravan was a piece of crap.


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