1997 740i transmission oil

[marine47]

I recently drained the transmission oil from my 1997 740i because I was told that I could refill the transmission oil. Does anyone know where the refill plug is located?

[cai]

I have heard from some mechanics that a way to do it is to put a funnel where the dip stick is located and fill it through there. Otherwise you will have to hunt for a plug on top of the transmission, or do it with a pressurized system.

Whatever method you use, make sure that you know how much ATF to put in so that you do not run short. Also, call the dealer and find out if it needs to be started briefly in order to fill the entire transmission.

Tread carefully.

[ibew595]

Originally posted by marine47@Apr 11 2004, 12:05 AM
I recently drained the transmission oil from my 1997 740i because I was told that I could refill the transmission oil. Does anyone know where the refill plug is located?

And use only the correct BMW fluid, which is expensive. If you use generic ATF you may really screw up the tranny.

[TECH]

Originally posted by marine47@Apr 11 2004, 02:05 AM
I recently drained the transmission oil from my 1997 740i because I was told that I could refill the transmission oil. Does anyone know where the refill plug is located?

The refill is probably square in the middle of the pan. You'll need a big allen to get the plug loose, and a pump to pump the fluid up in the tranny. It needs to be running when filling, at warm tranny temp. You're full when the fluid level is even with the plug.

[jyep]

When most people refer to the 7's tranny as sealed, they are referring to the fact that there is no readily acessable fill hole or dipstick.

As for the fluid change, I looked it up awhile back in the TIS. The actual tranny holds something like 13 quarts of fluid, however the change volume (what you get out by opening the drain plug) is in and around 5 quarts. Less than half of the actual volume.

In my opinion if you want to actually change the tranny fluid, you will have to drain and refill, take a short drive, and repeat at least 3 total cycles before you have replaced the better part of the old fluid. Changing only 5 quarts of fluid on a system with a 13 quart capacity is like only changing 3 quarts of your oil.

To test the fluid level, you have to open the fill plug and add fluid until it starts to spill out. However, there are several tricks to the procedure, including having it at the right temperature and starting the car at the right moment to make sure its full.

IT IS CRITICAL that you use the OEM BMW filter and not any kind of aftermarket brand. Look for the name "FILTRAN" stamped on one side of the filter. If its not present, you don't have the OEM part. Using a non-OEM filter can cause the dreaded whining/whirring sounds and may damage your transmission.

It's also critical that you use ONLY the recommended transmission fluid. With a 5HP24 transmission ('97 740iL), the fluid was Esso LT... something. Your mechanic should have a chart.

Just my $0.02

[shifty]

you should have never even attempted chaning the tranny fluid, it's lifetime fluid. But since you did, there is no filler cap for the tranny, you have to use the dipstick tube, also as the previous post suggest, ONLY use oem oil and ring, if you don't you WILL have a serious problem. At the dealership we use a special machine with a hose that runs into the tranny and sucks out the oil and then refills it. How did you drain the oil, dropped the pan? anyway, good luck and i hope you wont have problems like a lot of people who change the fluid do.

[jyep]

many different opinions on the "lifetime" tranny fluid. Lifetime means the lifetime of the tranny NOT the car which is normally about 100k so many owners are of the opinion it's ok to change.

you can go to www.roadfly.com; use the "search feature"; type in tranny fluid change and get some more info.

[shifty]

yeah lots of people change it at 100k. I still think it's completely unnecessary. I have cars at the shop with 300plus thousand miles with original fluid and the trannys run strong and dont slip or whine. Everytime i seem to change it the client returns with complaints of whining or slipping, so i discourage anyone from changing lifetime fluid, especially on the 5HP24 tranny which develops this problem more than others, probably since the E38 is heavy as hell and the torque itself is strain enough on it, not to mention the way some people pound on their cars.