Poll on Transmission Flush at High Miles

[DoubleA]

Flushing the tranny fluid when due can only be beneficial, unless you put some cheap or not recommended oil or perhaps you dont put the require amount. How in the world a tranny flush could destroy it ? Guys please wake up and get yourself a coffe before making assumption that make no sense at all.

[m5james]

The problem is people wait too long before they change the tranny fluid. NO fluid is lifetime, NONE...not even ZF's mythical Esso. 4 personally owned BMW's (countless customers cars that I've done), every 50k like clockwork, never a failed tranny yet...period. It's all nothing but opinions out there about the people results of changing fluid, but we never know how the tranny was treated by each individual user.

What most don't consider is that maybe it was already failing because they abused it - stop light racing everytime, Reverse to Drive w/o coming to a complete stop, hard driving on a cold engine instead of letting the engine AND tranny get to temperate via driving slowly AT THE SAME TIME (aka garage warmups that turn into immediate hard driving while the tranny is still cold). Most people wait until they get the slamming hard shifting before they address the problem. I personally am for preventative maintenance and don't believe in the "If it isn't broke don't fix it" mentality. Regardless of various peoples driving habits, personal maintenance beliefs, etc, one thing remains constant regardless of opinion...NO fluid is lifetime.

[FSETH]

Originally Posted by DoubleA

Flushing the tranny fluid when due can only be beneficial, unless you put some cheap or not recommended oil or perhaps you dont put the require amount. How in the world a tranny flush could destroy it ? Guys please wake up and get yourself a coffe before making assumption that make no sense at all.

If you read the links provided by JCL, he as well as two reputable BMW techs (Weasel and killcrap) give pretty good reasons why changing the fluid can have adverse affects. Especially at higher mileage when no previous services were performed.

Also, I read the poll wrong. There should be one less vote for "all good and no issues so far" and one more for "never changed and I am not going to".

[sfcl]

Originally Posted by JCL

For the record, I don't think it is fair to say that transmissions will fail if you change the fluid. Obviously that is not true, as most don't fail. However, I think it is fair to say that changing the fluid increases the chance of transmission failure. A better poll question would be: "If your transmission failed, have you ever changed the fluid?" Instead, the poll focuses on fluid change practices, and includes all those who haven't had a failed transmission. For that reason, the poll has limited statistical value.

Another good question would be: How many X have more than 100K with the original fluid and never got transmission problems?...

[m5james]

Originally Posted by FSETH

If you read the links provided by JCL, he as well as two reputable BMW techs (Weasel and killcrap) give pretty good reasons why changing the fluid can have adverse affects. Especially at higher mileage when no previous services were performed.

Also, I read the poll wrong. There should be one less vote for "all good and no issues so far" and one more for "never changed and I am not going to".

I run a BMW repair place here in Boise, am I mince meat here? I said in my previous post, you are correct...key words being "can" and "no previous". So for those w/ no problems now, lower mileage, etc....do it now or suffer later. I can't say it enough...NO fluid is lifetime and I've had to clean some pretty nasty stuff of the magnets in the pan, which NEVER changing the fluid will just continue move around in the system and make worse if the magnets aren't holding whatever else is floating around.

[m5james]

Originally Posted by sfcl

Another good question would be: How many X have more than 100K with the original fluid and never got transmission problems?...

Good question because that ties into what I said about people and their driving habits, cold engine procedures, etc. While my E34 M5 doesn't have the cool engine RPM's light that the E39 M5 has, the owner's manual gives basically the same procedure that only certain RPM's should be reached until the engine is up to a certain temperature. This also helps the transmission just as much. I don't even get close to redline in ANY of my cars till their at least to 1/2 or more of their normal temperature.

[FSETH]

Originally Posted by m5james

I run a BMW repair place here in Boise, am I mince meat here?

No, never said that. Just included those two because they are currently techs at BMW dealerships.

Just pointing out to DoubleA that is is not ALWAYS beneficial.

I agree with you and others that for a new BMW I would probably change the fluid regularly and disregard BMW's lifetime guideline, but for older BMW's with original fluid, I would leave it be.

[m5james]

I was just looking at shipping options for this lump of coal...i'll save it for someone else

I agree that its not always for everyone, but more for preventative maintenance as opposed to those w/ hard shifting issues looking for a fix, because by then it probably is too late. When I had my supercharged 01 Tacoma V6 (traded for the 7), there were many discussions then about flushing fluid if the trans was shifting hard. There was a general consensus then also that basically it was a lack of maintenance and it was too late, and that changing the fluid would somehow speed up the failure. I'm sure BMW's, or any tranny for that matter, is no different. Change the fluid before it becomes a problem, don't wait till you've got issues then expect an $80 fluid change to make miracles happen...the damage has already been done at that point.

I'd imagine all those little pieces of metal wash all around the transmission, slowly polishing away the checkballs and oil passages just like Extrude honing does to heads and intake manifolds. The passages get gouges, check balls allow too much fluid past, the fluid loses it flow characteristics since it's essentially contaminated = hardshifting. Hell, engines get the same damage due to lack of oil changes...scoring of the cylinder walls, clogged passages, etc. Changing the fluid to remove those metal particles before they do their damage prevents (or at least slows) that damaging process. The magnets holding those particles can only do so much, and they lose their efficieny to continue holding more and more particles as they get more and more built up. I've got pics on my website of a few tranny pans I've dropped, and those magnets were CAKED w/ fine grit and 1 w/ a sizeable chunk that shouldn't have been there

[RDAvena]

Dropped the pan and replaced filter and fluids.

68,000 Miles
Amsoil AFT used and I had the same moss growing on my magnets as the one above. Scratched off that "Lifetime" sticker and added an extra rare earth magnet to the pan just in case. At 110,000 now and no issues. Spirited driving, manual shifting, etc. At 125,000 I will do the same.

When the bean counters start doing engineering work that is when parts fail.

[Mikedd]

Originally Posted by m5james

I run a BMW repair place here in Boise, am I mince meat here? I said in my previous post, you are correct...key words being "can" and "no previous". So for those w/ no problems now, lower mileage, etc....do it now or suffer later. I can't say it enough...NO fluid is lifetime and I've had to clean some pretty nasty stuff of the magnets in the pan, which NEVER changing the fluid will just continue move around in the system and make worse if the magnets aren't holding whatever else is floating around.

This echoes what my indie says as well. I'm turning 92K and I will have this done in the new year along with gaskets etc.