How long can you safely run ATF?

[dsmith41]

Ford says in my manual to change the ATF every 30K in my Ranger. I am wondering if I can safely stretch it out longer if I use a premium synthetic like Mobil 1 or Redline.

I changed it once at 30K and I am sitting at 60K right now wanting to switch to synthetic.

 

[wavinwayne]

I've seen unconfirmed reports on the VW TDI forums of VW OEM ATF being run for over 300k miles without transmission failure.

My MIL's '02 Tahoe has 150k miles on the OEM fluid.

 

[c3po]

I think that I read for Amsoil ATF it is 50,000 miles for sever service and 100,000 miles for normal driving.

I am sure Gary or Pablo will chime in if I am wrong.

 

[Kestas]

Fluid life depends on how many shifts the fluid had to endure, i.e., city driving vs. highway driving. It may be 20K to some, 50K for others.

I believe as rule of thumb that you can double the fluid life if you switch over to synthetic.

 

[tig1]

My last car was a 96 Merc GM with 218,000 miles. I use Mobil 1 ATF in it and did 40-45,000 miles OCIs in the transmission. All was well when I recently sold it.

 

[tom slick]

I proposed a similar question awhile back and the answer was not to stretch the interval even with synthetic unless you are going to do a full flush each time.

I'm a drain and fill kind of guy so every 30k is fine to me regardless of basestock.

 

[[RT] ProjUltraZ]

Originally Posted By: dsmith41
I am wondering if I can safely stretch it out longer if I use a premium synthetic like Mobil 1 or Redline.


i would say so, but what did the dino ATF look like after 30K on your last change? how did your ATF look after 30K, was it really brown or sorta still red? and the smell

 

[Russ300H]

What's the factory spec in your Ranger? My daughter's Explorer takes Mercron V. I understand that it IS a Group III synthetic. I ran Amsoil in a Chrysler a while back and saw no difference in performance. The lousy trans [censored] out just as fast as with ATF +3 (spec at the time). That is not to blame Amsoil, it just showed no superiority in longevity. With the cost of transmissions today, I would consider doing shorter OCI as the miles pile up. I run 30K on the Explorer and 20K on the Chrysler with ATF+4.

 

[KLowD9x]

I do mostly highway on my vehicles, so I usually get them around 50-75K miles and do a 16 quart cooler line flush. They are all buttery smooth, just like brand new.

 

[dsmith41]

Like I said, there is about 30K on my current ATF fill and it still red and does not smell burnt at all.

Also, it is spec'd for Mercon V.

 

[01rangerxl]

You may be able to go with a longer interval, but personally I wouldn't.

My truck's trans was flushed with Mercon V at 30K, then flushed with BG Full Synthetic at about 58K miles. I will get it flushed again no later than 88K miles. I plan on getting Full Synthetic BG fluid again.

My truck has never had any transmission problems, and I plan to keep it that way for as long as possible. Some might consider it excessive, but the trans is the last thing I want to break, so I'm willing to flush with Full Synthetic every 30K.

 

[fsskier]

My vehicles seem to need greatly different ATF changes, regardless of the manuals guidance. Example:

Fairmont Wagon, rated to tow 2,000 lbs. Burned the fluid to dark brown smelled burnt quickly when towing 2,000 lbs, maybe in 500 miles or less.
Installed a big cooler, still burned the fluid, just slower.
Melted the second gear band at one point, had to replace it.
This transmission was failed by 30 k miles

Lumina APV, rated to tow 2,000 lbs, pulled 5,000 lbs 5 days a week, often long distances. Stock cooler kept the fluid red and fresh looking. Changed fluid once for no reason = the fluid still looked like new at about 175 K miles - and the transmission still performs like new at 265K miles.

Note that the APV used a lockup converter, this can greatly reduce the peak fluid temperature when in operation.

This is at least a 10 to 1 variation in fluid life in different vehicles - although I suspect the Fairmont would have also run huge miles without a fluid change if it never had to tow anything.

Sorry, if the report covers older vehicles, I keep them forever!! Just now starting to tow with a Sienna, it seems to not damage the fluid at all - peak temp, per the infrared gun is around 190 degrees. The Fairmont would push past 300 degrees when towing, even with the "3500 to 5,000" lb transmission cooler on it.

All my other vehicles have been 5 speed sticks, I use them in the "floor em and forget em" mode, they seem to be like new at 300k miles. Incidentally, all my FWD 5 speeds have used ATF!

 

[wander2039]

Depends on what your using it for. Hard use even with synthetic change at 30k or sooner normal driving 50-60k easily. I used synthetic in my Ranger and it didn't make it to 30k but I have the manual trans and I probably ask to much of my Ranger sometimes.