840 and 850 are not the same !!! (archive)

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: Oke here is a fact :
You don't have to to replace the transmission fluid in your x40i BMW since 1995 ever - period. That means 540, 740, 840.
Personly I don't trust this completely becuse the transmission has a conventional filter inside, that means it is replaceable. So I wanted to replace mine after 100k miles and yes you can. You have to use a special synthetic oil (from BMW 1 gallon approx 120USD) and a new filter kit (approx 50USD from BMW). On the side of the transmission there is a drain plug (i belive on the driver side) so you can drain what's in. Drain it to a clean pan becuse you might reuse all or most of it. Take the pan off (but be very careful becuse made out of aluminum) and pull the filter (I think there is one or 2 screw involved) install the new filter, oil pan gasket and put a pan back slowly. Follow the "center to the side" method when tightening the screws. Do not overtighten them becuse as I said aluminum so it can break easily. If everything has done you reached the hardest point refill a tranny. On the middle of the pan there is a deep hole and a screw inside. That is your refill hole. The oil you have just drained most likely to be reusable except if you see small particles, dirt in it, clean it with a good filter use a magnet to clean the metal powder and start refill. As I said you could buy a new oil 1gallon about 120USD, but it might worth it. You are going to need some of the drained oil anyway becuse the refill is about 6 quart and you can only buy per gallon. I don't think anybody wants to spend an another 120 on 2 quart. So refilling you probably need a fluid transfer pump and a long hose to refill and the correct oil level is basicly just below the hole. If you overfill the oil will come out of the hole. Pain in the a.. procedure but can be done and yes kind of an expensive, compare to regular transmission.
A few people told me I could have used a Mobil1 syntetic trans. oil from Autozone (about 6-7USD/quart) or any kinf of synth. trans. oil. I tried to call several places for the recommended (by owner manual) Shell oil, even Shell-USA but they didn't have anything. Later I found out AutoZone selling Mobil1 synth. but was to late.
So you might want to ask your stealer to do this becuse it is a lot of work under the car and in the middle which makes everything a bit harder.
They probably ask for 2-3 hours of labor but the parts are going to be about the same. 120 for oil, and cca. 50USD for the new filter/gasket.

note: I have a can of oil (1gallon) and complete gasket/filter set for sale but only if you are close to Florida. (the oil is really heavy so might not worth to ship) I bougth this kit for my 2nd 840 but then it turned out i have full warranty on the car so the delare would do this for me for free. (I paid wholesale prices for everything, as I always do)

BTW : Where are you ? You started posting questions right after I sold my '95 840Ci Silver baby in Florida to a delaer. Maybe you are the one who bought it from a dealer !?

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