Automatic tranny flush...to flush or not to flush.

[lukasbmw]

My 1999 e39 540i has 145k miles.

When I first got the car, people here advised me to have the tranny flushed pronto.

However, after talking to a few of my BMW "master tech" friends and picking the brain of a few local shop owners I trust, they advised me that flushing an automatic tranny may not be such a great idea.

I'm conflicted. I have some people telling me that I really need to change the fluid if I want my AT tranny to last.

On the other hand, I have some people telling me that changing the fluid in my AT tranny could cause it to go into failure.

I trust the expertise of people on both sides of the argument.


Two shops have told me not to touch the fluid.

A 3rd shop acknowledged the flush problems but told me they had a special procedure for flushing AT trannys. They drain the oil and inspect it for metal shavings. If shavings are present, they refill the tranny with the same oil. If no shavings are present, they refill with new fluid. This did not make much sense to me as it seems metal shavings in the fluid would mean the fluid has failed and the shavings need to be removed from the car...not reinstalled!

[Teaguer]

Do as the third shop suggested .
They know of what they speak .


While you are at it have them rip out those deathtrap seats and cobbled up belts in the E30 . :D

[Fanzotti]

In my proffesional opinion I would flush your automatic transmisson..... Down the Drain. not to be a jerk but auto's were made for mom's driving station wagons. Sports cars have sticks. Bite the bullet, you'll thank me.

[george graves]

On the other hand, I have some people telling me that changing the fluid in my AT tranny could cause it to go into failure.

Hun? - did they explain why this is?

[joshh]

A flush and changing the fluid are not the same.
Just change the fluid and call it done.

[92 mtechnic cabrio]

Sports cars have sticks.

Although I don't disagree with your statement, I would like to remind you that E30s were first purchased as yuppie-carriers. Automatics were prominent and they were used to float around town and realtors used them to show clients homes.

Of course I know about the E30 M3 and it's heritage, and I can say with confidence that the E30 M3 is THE sports car, I can't say too much about the non-M.

[Mike325]

Hun? - did they explain why this is?

From the techs at my work that I have talked to about this, the higher the mileage, the worse it is to do a full flush on the tranny. The reason was that all of the little particles and in the trans as well as the oil seals are "used to" the old fluid and the new fluid may leak.

[PeaveyBassist]

Most 540 and 740 automatic transmissions go out around 120-130k miles. At our shop almost every car with that transmission, it dies around the same time. We usually try to change the fluid and filter around 100k miles and they will last longer. We havent had any problems with changing the fluid. As long as you put the correct fluid back in I don't see a problem with it. I would recommend changing the fluid, or save up to have your tranny rebuilt.

Will

[trent]

My 1999 e39 540i has 145k miles.

When I first got the car, people here advised me to have the tranny flushed pronto.

However, after talking to a few of my BMW "master tech" friends and picking the brain of a few local shop owners I trust, they advised me that flushing an automatic tranny may not be such a great idea.

I'm conflicted. I have some people telling me that I really need to change the fluid if I want my AT tranny to last.

On the other hand, I have some people telling me that changing the fluid in my AT tranny could cause it to go into failure.

I trust the expertise of people on both sides of the argument.


Two shops have told me not to touch the fluid.

A 3rd shop acknowledged the flush problems but told me they had a special procedure for flushing AT trannys. They drain the oil and inspect it for metal shavings. If shavings are present, they refill the tranny with the same oil. If no shavings are present, they refill with new fluid. This did not make much sense to me as it seems metal shavings in the fluid would mean the fluid has failed and the shavings need to be removed from the car...not reinstalled!

Eric...there are many sides to this, and I have seen them. You are in a tough spot.

(1) Your fluid in there now, after 145K is your break in fluid. Yuck.

(2) Your fluid WILL have a very fine layer of silt on the bottom of the pan, and in the fluid. The fluid that has material in it, can be important if your tranny is getting worn. The key here is (as the 3rd shop is stating), that after this milage, the clutch packs in your transmission are relying on this extra "bite" of the fluid so that it will not cluch disks will not slip. That is the main idea.

New fluid, is clean, and would allow these disks to slip, causing your trans to go into failure. I have seen this happen first hand (a few times) and worn people of that this could be a possibly side effect.

Some shops don't want to touch the fluid period because they don't want the liability. Leaks have nothing to do with the problem.

When these people have these cars low mileage, I recommend them to do filter/fluid changes every 30-45K.

Have I ever rebuilt a trans? No.
Do I know exactly what I am talking about? No
Have I done services on the big 540i 740i trans? Yes
How many, more than one? Yes, probably about 75-100.
Out of these eric, I have seen 2-3 trannys go bad.

HTH

[bmw_e30]

My 1999 e39 540i has 145k miles.

When I first got the car, people here advised me to have the tranny flushed pronto.

However, after talking to a few of my BMW "master tech" friends and picking the brain of a few local shop owners I trust, they advised me that flushing an automatic tranny may not be such a great idea.

I'm conflicted. I have some people telling me that I really need to change the fluid if I want my AT tranny to last.

On the other hand, I have some people telling me that changing the fluid in my AT tranny could cause it to go into failure.

I trust the expertise of people on both sides of the argument.


Two shops have told me not to touch the fluid.

A 3rd shop acknowledged the flush problems but told me they had a special procedure for flushing AT trannys. They drain the oil and inspect it for metal shavings. If shavings are present, they refill the tranny with the same oil. If no shavings are present, they refill with new fluid. This did not make much sense to me as it seems metal shavings in the fluid would mean the fluid has failed and the shavings need to be removed from the car...not reinstalled!

FWIW. I flushed my 740i tranny fluid the 1st week I owned it. Same engine and tranny as your car. Car had 84k miles when I did the flush.

The fluid was dirty with very little metal in it. I also drained all the fluid including the torque converter fluid. Put a new trans filter and gasket.

The tranny feels much much better.

Be advised though that you need a special machine to evacute all the fluid in the tranny. And the Esso fluid that the tranny uses is very expensive.

I say do it 100%. The fluid should be changed every 60k or less.

[Fanzotti]

Although I don't disagree with your statement, I would like to remind you that E30s were first purchased as yuppie-carriers. Automatics were prominent and they were used to float around town and realtors used them to show clients homes.

Of course I know about the E30 M3 and it's heritage, and I can say with confidence that the E30 M3 is THE sports car, I can't say too much about the non-M.

All E30's are sports cars. If anything M3's are sports cars that are on there way to being race cars and if these former yuppie cruisers could talk they'd wannabe sticks... it's never to late to change. The number one swap on R3V isn't the S54, it's dumping a stick in place of an auto so it never has to deal with a yuppie ever ever again.

[TwoJ's]

All E30's are sports cars. If anything M3's are sports cars that are on there way to being race cars and if these former yuppie cruisers could talk they'd wannabe sticks... it's never to late to change. The number one swap on R3V isn't the S54, it's dumping a stick in place of an auto so it never has to deal with a yuppie ever ever again.

I'd say that an auto to manual swap is not the number one swap. M50.

And when did this thread ever become about e30's? He's talking about his e39. And no, all e30's are not sports cars.

This is an interesting topic. I have never heard anything of this. Can the same be said for every automatic trans, or just this one?

[HST]

I asked the same question about my 1997 540, I was told that the E39's have a lifetime auto transmission fluid, that should not be changed. I got my car with 136,000 on it, and the transmission had never been serviced, and I don't plan on it. With that kind of mileage, BMW trans or otherwise, I would not flush it.

[JGood]

What trent siad is 100% true. And yes, it does apply to most vehicles.

My input:

I have done probably 300 trans flushes. By flushes I mean disconneting the trans cooler line, connecting to a machine that takes this pressure and uses it to fill by means of the other open connection. They ranged from preventive maintenance (the fluid was still bright red) to last ditch attempts (the trans would shift or it slipped, and the fluid was BLACK). I can only rememeber 2 or 3 that went bad within then next 1,000 miles or so.

Does it happen? Yes. Should you be worried about it? That's up to you. The chances are slim, but if you CANNOT afford a new transmission, then don't do it. But be prepared for the transmission to fail earlier then normal if you don't regularly change the fluid.


EDIT: I don't know anything about e39 transmissions, but I do remember something about it being lifetime fluid. I guess you can forget about everything I said. There is certain vehciles I never worked on, and vehicles that had no dipstick were most of them.

[trent]

I asked the same question about my 1997 540, I was told that the E39's have a lifetime auto transmission fluid, that should not be changed. I got my car with 136,000 on it, and the transmission had never been serviced, and I don't plan on it. With that kind of mileage, BMW trans or otherwise, I would not flush it.

It will go out on you soon.

The key here is, what does "lifetime" mean? My dealer fessed up once, lifetime in their terms means 100,000 miles. Another example that they do not want cars to last these days.

For these trans to last, they must be serviced.