To change or Not to change automatic transmission fluid

[Wayloncle]

A guy I used to work with took his Explorer to the Ford dealer and told them he wanted a fluid and filter change. They wouldn't do it. His didn't have a dipstick or anything either.
He finally talked them into doing it, they called and said it was ready, so he crawled under the truck and looked at the bolts that he had marked. None had been touched, and they told him they changed the filter,he asked to see the old filter and of course they couldn't produce it. He had a long fight with the managers and calls to Ford. He eventually got what he wanted and they changed the filter and all, but in the end they didn't recommend changing it, he just raised enough stink that they did it to shut him up.

This really doesn't answer anything but this thread reminded me of the story

 

[davel501]

My brother is a master mechanic and will not let me change the fluid in my '05 Cobalt with 132k. Says it probably wouldn't make it out of the shop after.

 

[Murf'n'surf]

You guys are kinda freaking me out after just changing my tranny fluid after 153k!!!!

I'm working of polishing her up today and will be putting a for sale sign on her Monday. This has been my plan all along, I'm not selling due to possible transmission issues.

 

[Big Shasta]

I just don't get it. Someone explain to me the logic behind a mechanical hydraulic system working better/longer on old worn out fluid than it will on new fresh fluid. I just don't buy it.

Neither do these folks:
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2202175

Total "old wives tale" If it was true in a transmission, why wouldn't the same theory apply to engine oil?...nobody would ever say that for engine oil.

 

[sstegh]

Agreed. I don't understand how leaving the old oil in there can be a good thing.

 

[Boat Crazy]

When I bought my ford diesel used, the first thing I had done was the transmission oil changed. I did not know how hard it was used for towing from the previous owner. I am not buying the "do not change your transmission fluid" Why is it recommended in the owners manual?

 

[BlacklimitedS]

While I agree with many points listed above I too have heard horror stories about transmission fluid changes on high milage vehicles. I would ask the question is it worth the cost and potential problems. I am guessing your son will average 10K or less a year. Assuming all other maintenance has been performed 200k shouldn't be an issue. I just bought a new Toyota Tundra and have not looked at the maintenance schedule but I will change the tranny fluid when it is recommended.

 

[motorboater]

I just don't get it. Someone explain to me the logic behind a mechanical hydraulic system working better/longer on old worn out fluid than it will on new fresh fluid. I just don't buy it.

Neither do these folks:
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2202175

Total "old wives tale" If it was true in a transmission, why wouldn't the same theory apply to engine oil?...nobody would ever say that for engine oil.

I disagree that its an old wives tale. Some mechanics may embellish the facts or figures, and I also believe that overall the chances of doing any damage with a flush (zero chance with a drain/fill) are small, but the chance exists. It has happened to me... on a vehicle with 135k miles. Considering the "lifetime" of the component. I'd say it was a little premature but it was also in a car I bought used as the 5th owner. Win some lose some.

I think new fluid is almost always a good thing. The method for changing it is in question. Also a factor is how long a person intends to own the vehicle, how many miles it had when acquired, prior use type and prior service history, etc.

The only way to "see" exactly what the inside of your transmission is "seeing" is to draw a sample and have it tested.

 

[Big Shasta]

The only way to "see" exactly what the inside of your transmission is "seeing" is to draw a sample and have it tested.

I'll agree with this 100%...... and any worn fluid is going to come back as "needs replaced". Imagine if you got results back from the analysis lab that said ....Too late, it's SO bad that you can't change it now.

 

[woodard1983]

Most don't have serviceable transmission filters anymore. My Tundra doesn't even have a transmission dipstick. Blew that one Toyota.

Toyota's have a "sealed" system, tranny started slipping on my Sequoia and I asked them why the heck it didn't have one...they said they seal the tranny's and that was the design the engineers thought best....they also could not explain why my fluid was 6 qts low :/

 

[Big Shasta]

Toyota's have a "sealed" system, tranny started slipping on my Sequoia and I asked them why the heck it didn't have one...they said they seal the tranny's and that was the design the engineers thought best....they also could not explain why my fluid was 6 qts low :/

Guess who does regular drain and refills on his "Sealed Transmission"? (Hint, it's me!)

 

[davel501]

Just asked about it. Flushing a transmission with a cleaner will clean out the varnish and gunk that is keeping it sealed from years of wear. Think like how our Yammie engines leak with synthetic oil.

The other thing that happens is some of the flush machines put pressure on the transmission and my break internal parts.

 

[-klb-]

F150 transmission lock up converter clutch does not play well with the flush additives at all. But I'm about to have to do a filter and fluid change at 100k miles because the fluid is in bad enough shape that the lock up clutch is slipping. Hoping no issues show up after.

 

[Big Shasta]

Just asked about it. Flushing a transmission with a cleaner will clean out the varnish and gunk that is keeping it sealed from years of wear. Think like how our Yammie engines leak with synthetic oil.

The other thing that happens is some of the flush machines put pressure on the transmission and my break internal parts.

Not suggesting additives or flush solvents or even a flush machine, just a drain and refill....and if there is a serviceable filter in it, change the filter as well.

First I've heard of synthetic oil causing Yamaha engines to leak. I have used synthetic (Mobil One) in my 2005 since the day I got it. The previous owner did not....I got it 5 years old. It's never leaked a drop.

 

[davel501]

There are few folks that have reported a drip with synthetics or at least that is what they blamed it on. Search around here and the old site.

 

[PEARCE]

Not suggesting additives or flush solvents or even a flush machine, just a drain and refill....and if there is a serviceable filter in it, change the filter as well.

First I've heard of synthetic oil causing Yamaha engines to leak. I have used synthetic (Mobil One) in my 2005 since the day I got it. The previous owner did not....I got it 5 years old. It's never leaked a drop.

You're one of the few lucky ones to not have any oil leaks from our generation of MR-1's. I'm the original owner of my boat and I used to always run Yamalube till about three years ago when I switched over to Belray. From what I've read and understand is Yamalube is a blend and I know the Belray I'm using is a full mineral with more additives then what Yamalube has. The leaks haven't slowed much since switching to full dino, but it's an easy fix with a paper towel before I check the levels and start the motors.

 

[Big Shasta]

You're one of the few lucky ones to not have any oil leaks from our generation of MR-1's. I'm the original owner of my boat and I used to always run Yamalube till about three years ago when I switched over to Belray. From what I've read and understand is Yamalube is a blend and I know the Belray I'm using is a full mineral with more additives then what Yamalube has. The leaks haven't slowed much since switching to full dino, but it's an easy fix with a paper towel before I check the levels and start the motors.

Interesting, I can't believe I haven't heard of this before. I guess I'm dodging a bullet. I'm sticking with it.