Re: Auto Trans Fluid Change (archive)

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I know that BMW says that the Tranny Fluid in my 91 CiA is "Good for life", but that makes me really, really uncomfortable. What do you guys recommend, and what do you run in your cars?

I just did my Inspection II on my '93 '50cia which included tranny,brake,radiator,hydraulic,rear end, oil, and washer fluid change.

The filter for the tranny is a bit different than you may have seen before. I bought mine at the Stealer....I think it was around $30.

I asked a LOT of questions prior to making this change, so I'll tell you what I learned. Even the Stealer guys told me to only replace the fluid that comes out from the drain, and the little in the pan. Recognize that some fluid will remain in the converter ( you do have an autobox don't you? ). But that remaining fluid can stay in the car without any concern. It is, I'm told, actually beneficial to let it stay in as it contains "key ingedients."

I lift my car with the factory jack ALWAYS. Doing so allows me to use jack stands under the key points under the car.

At any rate, it's pretty straight forward from there. Pull the plug, let it drain ( should be at least warm to hot to drain well ). Then disconnect the "dipstick" hook up. My car required a 30mm wrench...pretty big unless you have a big Crescent wrench. ( you can buy a 30mm combo wrench at Home Depot, and, ahem, return it after the job..$14.)

I have air tools, which made the pan removal simple. 6 brackets support the pan, and the gasket is great, and can be reused...those Germans are great. Careful not to spill on your face...even though you've drained most of the fluid already.

Visually inspect the guts, and take the pan to your workbench. Two magnets in there will have metal "fuzz" on them. Take them out and clean them, and thouroughly wipe out the pan...NO LINT.

Now, here's what I did for the refill: I Calculated how much fluid I had drained by using a funnel and an empty standard oil plastic bottle. Understand? So you'll count how many bottles you fill as you dump the drained fluid into the bottles, and then into a proper container for disposal.

Remove the filter with Torx wrenches...3 or 4 screws as I recall. I have a Torx tool which is like a Swiss army knife..a variety of sizes...i think it's 3mm Torx.

Buy a funnel with a long, long "hose" thingy on the bottom, make sure it will fit inside of the dipstick hole, or you will spill all over the place. The hole is only about a half inch across after you pull the stick out and set it to the side.

Then slowly add Mobil 1 synthetic....and enjoy the results IMMEDIATELY. I was amazed, truly how well my baby responded to new fluid.

I believe the best way to check the level on the fluid is to start the car first thing in the morning and check the ^$*#) stick....which I find very hard to read. But remember, the high and low marks on the stick are separated by only .6 pint of fluid....so be careful...have the car on level ground!!

Mobil 1 is your only choice. Do it today and you'll be trouble free for another 60k miles, although I think I may change my fluid every 10k as I ride it hard....love to drive in "M" mode.

If you don't have access to jacks, or are not a mechanical type...I'd go to any of the oil change places...I have Castrol Blend in my car 20/50. I like these places because they don't lift the car up at all. Just ask the manager (usually a kid who is totally jazzed by the car anyway) your situation. You provide the filter, the fluid, and the instruction....I insist on going down the steps and getting that view that we rarely get....course I'm usually ready to start detailing the mufflers or something...

You could do the rear end as well while you are down there. Simple too. Two big hex screws...not sure of size. Pull out one for the drain, and the other one serves as the fill hole. You could use the method outlined above to track the volume you will need, but you can also use the "finger" method. I used Castrol Synthetic gear oil...got it at S & G.

Ok....there you have it...I expect a full report...Oh yeah, I'd buy 5 ATF's...may or may not use all of them.

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