Transmission and/or cooling system flush - how often do you do these?

[soonertodd]

According to MotorAllData the service interval on the ATF is 100,000 miles and the coolant is 150,000.

As for trans fluhes in general. I think its is good aslong as they just flush with ATF and no snake oil cleaners

the 100,000 mile on the atf is inspection only

 

[Toney]

I think flushing is a money maker. Also if the filter is dirty enough to be changed your transmission is already toasted

 

[swampratt]

Yes some manufactures do state 100,000 miles.
I have seen many newer 1999 and newer all the way up to 2011 chevy ford dodge honda transmissions kick the bucket at 75,000 to just under 100,000 miles....Is it the issues with long change intervals or is it a design flaw.(flaw or on purpose)
Sorry but i hate newer vehicles.
And i will stick to my old ways of 20,000 miles..
I should state i do not hate them , i just have no respect for the things..they can make them last 4x longer if they felt like it and they can make them get 2x the mpg if they felt like it..
But they just want to stick it to us with bells and whistles and shoddy craftsmanship.

 

[arshooterone]

Good maintenance is cheap in the long run. Transmission failures after long-delayed fluid service can wash away varnish that has become a part of the internal sealing. Routine maintenance prevents varnish deposits and keeps the seals soft. Coolant becomes acidic and will dissolve the components it contacts. Flushing neglected coolant can expose holes in the system that already existed, but were sealed with debris. Brake fluid becomes moisture saturated and corrodes expensive cylinders and ABS controls. Nothing is more fun than replacing a $2000 ABS control module. Will flushing fluids that are filled with dirt, varnish and carbon that has become a part of the component? No, because the failure has already occurred.

This^^^^^^^

Spent 25 years in a GM dealership and service is a lot cheaper than repairs. At 50,000 miles I'd flush the transmission. And most coolant is recommended to be serviced at 150,000 miles or 5 years.

 

[SoonerP226]

A friend of mine used to be a transmission engineer for Ford, and part of his job was dissecting failed slushboxen to figure out why they died. He said, unequivocally, that a transmission flush (i.e, replacing the old fluid with new fluid, not one where they put in additives) will not kill a transmission; if it fails after a flush, then there was something else wrong, and it was going to die anyway. He also said that "sealed for life" transmissions are a product of the marketing departments, and he strongly recommends a transmission flush every 30K miles, regardless of what the manufacturer says.

There are a lot of old transmission guys who will tell you to leave an unmaintained slushbox alone, and they do see a bunch of failures on transmissions that first get serviced at over 100K miles. Unfortunately, most people don't see the correlation between 100K+ miles of abuse and the failure, just the correlation between the last (first) service and the failure...

 

[Lurkerinthewoods]

My son works in a transmission shop and he told me you should never flush a transmission. Simple fluid and filter change about every 50,000 to 65,000 miles.

 

[Toney]

You know there is at least one internal screen that the backflushing is not gonna get stuff past, what was safe somewhere now will have another chance to run through the system.

Heat kills tranmissions

 

[Nilbog]

Same thing happened to me. I won't do a transmission flush again.

From my one time experience, I do not touch the transmission. The one and only time I had a transmission flush done, it crapped out on me three months later. Odd? Maybe, but it was working just fine before the flush.

 

[flybeech]

I tend to be a bit obsessive about fluid maintenance. I've seen 10 year/100,000 mile DexCool antifreeze turn to a gelatinous goo long before the recommended interval. I've also seen low-mileage transmission fluid stink to high heaven from being overheated. Personally, I view the manufacturer's recommended intervals as more a guide than a rule. Operating conditions can shorten or prolong the life of the component. Back in the day and as recent as the mid-2000's, many manufacturers provided a drain plug on the torque converter, enabling most of the fluid to be drained from the transmission. Those days are gone and the transmission fill tube and dipstick have gone the way of the torque convertor drain plug. Today, a thorough transmission fluid service must be performed using a running drain and fill procedure including the transmission cooler lines and many shops use the BG system of bladders to exchange the fluid through the cooler lines. Modern transmissions are terribly costly to overhaul and not field service friendly. Not only do I replace the coolant and transmission fluid long before the recommended interval, I do the same thing for the brake hydraulic system and the power steering. Manufacturers intend the vehicle to last as long as the warranty and prevailing loan duration, to encourage replacement.

If I knew I was going to replace the vehicle at a certain time, my maintenance might be at longer intervals, than if I intended to run it hundreds of thousands of miles. I wouldn't expect most motorists to observe my obsessive/compulsive maintenance schedules, but I drive mine until the wheels fall off and when they do, I just glue them back on and keep going.

 

[dieseltech09]

the 100,000 mile on the atf is inspection only

You are right I just glanced at it the first time.