OK I did transmission fluid flush on my 02 4.4i

[upallnight]

Do they really endorse BMW's maintenance strategy or do they just want to sell transmissions to BMW? After all when the trans crap out, do ZF or GM repair the trans or do BMW perform the repairs?

[jgold47]

I'm on the fence with this. I've had very few automatics, but my e36 has 160K miles with no service records showing a tranny change. Unfortunately, its weeping a little bit, which means I may need to drop the pan and re-do the gasket. I'll probably do the filter at the same time and top it off, but I dont think I am going to do a full change.

I keep reading threads where people do the tranny service at high mileage and then 6 months later the tranny dies. I've read that the clean fluid does too good of a job cleaning the engine and the gunk it dislodges causes the passages to clog.

[mysweetx5]

That you tried to make a point on changing the transmission fluid
but at the same time, you plan on messing things up by doing basically
the same mistake a few people be doing outhere. By: topping-up and
not trying to add as much fresh fluid as you can, & not changing the filter.

By doing so, you risk to cause more damage because (the pan needs to be
dropped in order to be cleaned, including the 4 magnets inside).
If you knew how dirty they get over the time, you would be more excited
to clean them, because this is where all the wear metals seated.
The previous job upthere in this forum with the blue X5 4.4i was from me.
meaning: that may tell you something that I'm aware of because I've been there

I did mine for the 1st time at 125,000 miles, now I'm still driving strong
the same way with nearly 128,000 miles now. My suggestion is just that
Don't just top it up! Do it the right way, by removing as much dirty fluid
you can pull out. And Fill-up with the proper fluid, and replacing new filter.

[Hoser]

There are not many companies around that know more about automatic transmissions than Allison. They had to come up with new oil formulations when GM dropped certification of Dexron. When that happened everyone was open to put burro pee in a can and call it dexron. The engineer who wrote the specs on Allison's replacement synthetic Syntec when retired, joined an RV forum about Allison. They were forced to re-adjust their thinking about lifespan of trans fluid-even with their new super juice. To those who "know" someone who changed their fluid/fliter in their automatic and ended up blowing up their trans- I think I would challenge them to name names. It only stands to reason that removing any of the dirt and byproducts of a piece of machinery with friction surfaces and replaceing the lubricant with fresh new lubricfant, can only do good for the same reason it does in an engine. I doubt that any machine manufacturer has their own oil well, oil research section, testing labs, health & safety standards approval section (this stuff is in human contact). I think it is safe to say BMW and others use rebadged cans of lubricants and chemicals. The fact that Ford uses the same ZF6HP26 tranny in a Lincoln Navigator and specs Motorcraft Mercon SP fluid at $8/liter should be a little enlightening to those who are receptive.

[TwinTurboGTR]

Good morning. The last time anyone posted on this thread was Dec. of last year. While your information is concise and well written, the topic has been beaten to death. There is a consensus from other members and former techs on this forum that support you don't touch the tranny if it has hit 100k and has never been cracked open before. Using the old adage of "if it ain't broke..." The exception would be if the tranny is experiencing problems, then change fluid. You may be looking at an overhaul of the tranny anyway, so as a last ditch effort to squeeze the last bit of life out, you could drop the pan and change the oil and filter, but end result normally is the same.

[jsoto]

Just wanted to add this to the wikipedia.
For me, ZF5HP24.
3 Bolt Drains/Refill.
1 Pan Drop, NO Filter Change.
Fluid was cheap for me.
No issues up to this point.
Note, I have been experiencing the 2/1 downshift when I approached 98K miles, but this happened more/noticeable when I was on a incline and in stop and go traffic bumper 2 bumper rush hour traffic.

Full Pan Drop, filter, line flushed - I think I used about 11.25 qts .
The 2-1 downshift magically went away !
2500 miles later, G1 started slipping on me. 2 minor times with a hard bang into gear, then later in the day, straight slip until it hit 2nd gear with a hard bang and then limp mode, 1 stop sign away from home.

I did not hesitate going with the rebuild..
She's running strong. I'm still putting it through it's paces but sofar, sogood.

[Hoser]

Yes after I posted I looked at the previous posting dates and realized I should go to bed. One technique for changing out tranny fluid owners of large RV developed was to, change out filter, then undo the return line from the tranny cooler and drain into a bucket while filling with new into the other return line section-with help from someone idling the car while this oil change circus is going on. It at least allowed the closest thing to 100% oil change. This involved transmissions with 18 to 25 liters capacity-but it is just as important for our cars. Anyone ever put forth this changeout technique?

[740ilDuke]

Great write up, I did this last year. Still shifts like brand new at 185k. As far as the torque converter, since you changed the filter all you need to do is drain and refill after a few thousand miles. I changed mine, then went back and did a simple drain and refill.

If any of you are planning on keeping your car for the long haul, this is a MUST do thing that is worth its weight in gold.

For the earlier model X5's you can also drain and refill the transfer case without having to reset adaptive values, it also uses the same fluid as your transmission.

[e30cabrio]

How do you get the fluid out of the TC?

[740ilDuke]

Depends on the model, some have a drain plug some you have to use a hand pump and pump it out.