GM 6L45R Auto Tranny - Change Fluid @ 190k?

[zeddy]

Picked up a used 3rd car for fun - 2007 BMW 328i coupe with the GM GA6L45R unit which is also used in the Cadillac ATS. Car has 190k miles.

No prior records came with the car, but Carfax shows the car was maintained by BMW dealers until 130k miles. None of the carfax records show that the car received any transmission work or fluid changes, but I'm not one to place 100% certainty on what Carfax says or does not say.

BMW claims ATF is lifetime, but I've heard of dealers recommending fluid changes at 100k. The GA6L45R fluid change includes dropping the ATF fluid sump/pan, R&R both the pan gasket and the built in filter.

My question - should I change the ATF fluid and risk potentially killing the transmission? Or just leave it alone? Is this risk somewhat mitigated since there is a built in filter that I will be changing? If I do change it, the manual recommends Dexron VI - would Maxlife ATF be okay or should I go with Valvoline or even Supertech?

Some additional thoughts - I've personally experienced a transmission that was killed after doing an ATF change. Our family's 1997 Camry 4cyl had it's first ATF change at the 120k mark. Almost immediately the transmission started shifting very roughly, and within about a hundred miles or so, we had to replace the transmission.

Since this BMW will be the 3rd car, I expect to drive it around 3-5k miles per year at most. I don't know what our long term plans are with the car - I can imagine keeping the car 3-5 years, but I can also see it going in a year or two. Regardless, given the age and mileage, my first plan is to change all fluids and filters. Just unsure whether it is safe to change the ATF fluid.

 

[demarpaint]

I'm from the school of thought that if an ATF fluid change "killed' a transmission, it was going to die anyway. I'd change it. I also believe that changing the fluid might actually extend the life of a borderline transmission. My

 

[Oro_O]

Originally Posted By: demarpaint
I'm from the school of thought that if an ATF fluid change "killed' a transmission, it was going to die anyway.


+1.

Quote:
should I change the ATF fluid and risk potentially killing the transmission?


Think of it this way - do you view changing engine oil as a risk of "potentially killing" it? Transmissions are similar, but with much longer service intervals. No fluid is "lifetime" - they wear and degrade, and fill with contaminants past what the fluid can hold in suspension.

Do a couple of drain/fills if you do not have a cooler line to swap out all the fluid at once. Changing the filter is less critical than changing the fluid, so don't let hesitancy about dropping the pan stop you if that is an issue. MaxLife makes a very good Dex VI substitute and is in one GM and two Toyota transmissions of ours, all over 100k and one over 250k miles, all working perfectly.

 

[turtlevette]

Suck out a couple of quarts and replace with maxlife. Drive a couple thousand miles and repeat. Until the fluid comes out fairly red.

 

[toneydoc]

I like turlevettes idea. That is exactly what I do to my Jeep trans fluid. I buy 2 quarts about1-2 times a year. Suck out 2 through the dipstick hole and put in 2 new quarts. The fluid tends to stay a nice red color. And I have had no problems with the tranny yet. Hope it goes another 20 years

 

[Doog]

Originally Posted By: turtlevette
Suck out a couple of quarts and replace with maxlife. Drive a couple thousand miles and repeat. Until the fluid comes out fairly red.



+2 I have done this numerous times....never killed one yet

 

[Ramblejam]

Originally Posted By: turtlevette
Until the fluid comes out fairly red.


There's a better way of establishing where you're at: http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3332159/Transmission_Partial_Drain_CAL

 

[JTK]

How serviceable is the 6L45R? Does it have a dipstick or drain/fill plugs? If not, it's hard to believe a basic pan drop and filter change would do anything other than help it. It's only swapping out maybe 1/3 of the ATF in the system.

I remember when the 3-series had the GM 4L30E. I used to follow those quite a bit having had several late model Isuzu Rodeos and Troopers in the family at the time. They shared that same trans, along with the Cadillac Catera IIRC.

 

[GaleHawkins]

zeddy sounds like you found a 'fun' car for sure.

I do not think the fluid change killed the 1997 Toyota transmission in any direct way. Hard shifting is seldom a mechanical problem but a dirty transmission issue in my experience and from reading on the subject.

Everyone may take a different approach to when/how to replace ATF as the years/miles add up. Any method one prefers is what I suggest.

For the last 10 years we have been doing total fluid change outs using the bucket flush approach by pumping the old ATF out of the exit cooling line either pre or post external cooler based on easy of access.

We just did this on the new to us 2006 Ford with the AWF21 transmission with 110K miles on the car/ATF per the owner for the past 10 years and just got back from a fast 1600 mile trip in it.

Read up on Lubegard Red for your 'new' BMW fun car. I just learned about it a couple weeks ago and can state it greatly improved hard down shifting while running the Seafoam Trans Tune as a 200-300 mile pre bucket flush step. After the bucket flush we refilled with the Mobil 3309 (Aisin Warner spec) and I topped off with 16 oz of Lubegard Platinum for the fun of it since the flushed Lubegard Red had improved shifting so much.

Dumping 2-3 quarts at a time is a very valid way to clean up a very dirty transmission. The valve body and servos getting dirty and it being flushed with all new ATF can lead to issues in my view as happened with your Toyota.

Over the last two weeks I have added Lubegard Red to another four old transmissions with clean to dirty ATF. It is a cleaner (esters) and an 'add pack' as best as I can learn. Not sure why I had not read about it before now.

Have some learning and driving fun with your BMW. The 1985 528e with the 5 speed manual was the most fun of the four old BMW's I have owned in the past.

 

[Gasbuggy]

Originally Posted By: turtlevette
Suck out a couple of quarts and replace with maxlife. Drive a couple thousand miles and repeat. Until the fluid comes out fairly red.



This is how I would do it.

 

[Pontual]

Some say lifetime, lacking info in timelimit i.e. lifetime is below 8 years of short tripping. OIL stress slowly with long drain time, but it does oxidate, specially by getting over several heating cycles, humidity and aeration. I changed such lifetime on my C5 with 150k km (100k miles) that took 15 years to run, so a 15 old original fill, and found a bunch of polymerized white almost a grit kind of deposits on the bottom of the old oil recipient. Im glad I double flushed it, unscrewing the drain plug, since sucking it out wouldnt get the grit at the bottom of the sump.

 

[zzyzzx]

Originally Posted By: Doog
Originally Posted By: turtlevette
Suck out a couple of quarts and replace with maxlife. Drive a couple thousand miles and repeat. Until the fluid comes out fairly red.



+2 I have done this numerous times....never killed one yet


I have also done this. I now have 233K miles on that 20 year old automatic transmission and drive to to work this morning just fine.

 

[Oro_O]

Originally Posted By: JTK
How serviceable is the 6L45R? Does it have a dipstick or drain/fill plugs? If not, it's hard to believe a basic pan drop and filter change would do anything other than help it. It's only swapping out maybe 1/3 of the ATF in the system.

I remember when the 3-series had the GM 4L30E. I used to follow those quite a bit having had several late model Isuzu Rodeos and Troopers in the family at the time. They shared that same trans, along with the Cadillac Catera IIRC.


If it's like the 4l60E, then no stock drain plug. There are aftermarket pans with plugs in it for cheap for that unit (~$30), cheap enough it's not worth buying a vacuum siphon or welding in a plug. Line swaps are so much better for not diluting new fluid with bad.

I rebuilt a 4L30E last summer; out of my Acura SLX (trooper). Interesting the Cadillac and 3 are still sharing a transmission decades later.

 

[JTK]

Originally Posted By: Or

I rebuilt a 4L30E last summer; out of my Acura SLX (trooper). Interesting the Cadillac and 3 are still sharing a transmission decades later.


Yeah, the 4L30E's were interesting beasts, with the added on housing and additional pan for the 4th gear assembly. I don't think anything beyond 2003-4 used that AT. The Trooper was gone and the 2004 Isuzu Rodeo could be had with an Aisin-Warner AT or the 4L30E depending on engine choice.

 

[zeddy]

There is a drain plug, but you won't get nearly as much out vs removing the entire pan. I'm not comfortable with the evac of fluid via the cooler route (not even sure where it's located on this car), and would rather do the drain/fill dilution method.

Unfortunately there is no dipstick or fill tube - fill hole is located on the transmission itself and only way to know the correct amount of fluid is to fill through the fill hole until it overfills. This requires the car to be raised and leveled.

My plan of attack is to get 2 jugs of maxlife atf, drop the pan and change the filter and refill. After a couple hundred miles, just do a drain and fill with the remaining maxlife to try and get it better diluted. I'm going to skip the lubegard initially even though the reviews seem very positive, unless the fluid change doesn't do anything to make it shift smoother. Then I'll try adding lubegard on the second drain and fill.

If the tranny goes, the tranny goes. I guess it'll be a good time to learn how to drop a transmission.

Thanks for all the advice

 

[Oro_O]

Originally Posted By: JTK
Originally Posted By: Or

I rebuilt a 4L30E last summer; out of my Acura SLX (trooper). Interesting the Cadillac and 3 are still sharing a transmission decades later.


Yeah, the 4L30E's were interesting beasts, with the added on housing and additional pan for the 4th gear assembly. I don't think anything beyond 2003-4 used that AT. The Trooper was gone and the 2004 Isuzu Rodeo could be had with an Aisin-Warner AT or the 4L30E depending on engine choice.


It was certainly a little funky and tricky, and I'll never hesitate to rebuild any other transmission since that was the oddball. Everything else is easy-peasy, lemon-squeezy in comparison.

Funny story about the 4L30E and Isuzu. Jerry Lemond, who was the national technical trainer for Isuzu (and I think Acura/Honda, too) for these and other products said that he and other experts BEGGED Isuzue not to use the 4L30E when they considered it. he said that internally, they were told they were considering an AW vs. the GM -30E. The OE cost difference was like $75/vehicle more for the AW, despite the AW being JDM and relatively local vs. the GM units coming from France (that is where that unit was solely produced, btw). All the tech force argued for the higher cost AW unit but the bean counters demanded the GM for the $75/vehicle margin. And then they lost their shirts on it with warranty claims and reputation damage. Save a penny, lose a pound.

The story is on the planetisuzoo website somehwere in a post of his though I can't easily find it and link it now.

As I understand it, the 2003 Axiom came with the same 3.5L V6 and 4L30E, then in 2004 it got the DI engine and AW transmission. The tranny is great, but they say run from that engine as while having great potential, was one-off and trouble-prone as so many earlier DI engines are.

To be fair, after 98 or so, the 4L30E was vastly more reliable and by 2002 very good; they had worked out kinks, leaks, introduced PWM to the TC to moderate line pressure, etc. The one in my 98 was going wonderfully at 160k miles when it failed only do to a bad copper crush washer that leaked out fluid, was not spotted, and toasted the 3rd gear frictions.

But I'll never buy a French-made GM transmission again, that's for &**% sure.