shogun
07-04-2006, 11:58 AM
copied from Bimmerboard, replies to a E32 750iL owners, built year 1990
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The recommended transmission fluid is Dexron II. Dexron III is a suitable substitute. As for the 15W50 motor oil reference, this information is found in your owner's manual. Since I do this for a living, I also have information like this as well as repair and service information available to me at a moment's notice (have an automotive data base installed in my computer which is updated quarterly).
I can tell you an easy (but a little messy, not too bad though) way to do your own transmission fluid flush on virtually any vehicle WITH A DIPSTICK/FILLER TUBE ONLY. This is a safe and effective way of replacing the fluid in your transmission (torque converter and all) as opposed to 'dropping the pan' which only allows you to replace about a quarter to a third of what the transmission actually holds, since there is no drain plug in the torque converter. Simply remove the top transmission cooler line (this is the feed line from the trans for a BMW) from the radiator and attach a hose to that line running it into a bucket (one that holds at least as much fluid as you're exchanging). Then install a funnel to the transmission dipstick/filler tube. Our transmissions hold approximately 12 to 15 quarts of fluid, so have three to four 1 gallon jugs of fresh fluid on hand. Set the emergency brake, block the drive wheels securely (having an assistant to man the ignition, shifter and brakes would be ideal for this). Start the engine and put the transmission in gear, (not park or neutral since the pump in a ZF trans doesn't really circulate much unless it's in gear), start to pour fresh fluid into the funnel at about the same rate that it's being pumped out into the bucket until you've used up (and have pumped out) 3 or 4 gallons (depending on how much you are exchanging). By this time the fluid being pumped out should be nice and clean. Shut the engine off and re-assemble the cooler line to the radiator. I know first hand that this works because this is essentialy how it's done using a transmission flushing machine, and his is how I did it on my own E32 when I first got it.
***NOTICE***
**As with any DIY procedure, undergoing this is done at your own risk. Servicing your transmission is purely for maintenance purposes only and is not recommended for 'fixing' an already existing mechanical problem. It's best to drain and remove the trans pan so that you can inspect it for signs of internal transmission damage or failures. Should any signs of this exist (chewed-up metal parts or whole pieces of clutch material), then put the pan and the fluid you got out back and consider replacing or having the transmission rebuilt.
*If fluid begins to pump out of the fitting from the radiator when you start the procedure, immediately shut off the engine and install the hose on the radiator somehow, or on the other line at the bottom of the radiator. This is caused by a reversal of the fluid flow to the radiator from having lines reversed (either by design or mistake and poses no danger to the transmission or radiator (doesn't matter which direction fluid flows through the cooler, as long as it flows and is cooled)
*Do NOT perform this procedure on a 'sick' transmission which slips (check the fluid level first if it slips to make sure it's full), has alot of debris in the pan or is mechanically unsound.
*Do NOT attempt this procedure on a transmission which is not fitted with a dipstick tube, since you will not be able to pour fresh fluid in while the old fluid is being pumped out.
*Do NOT overfill or underfill your transmission. Doing so will cause foaming (leading to fluid expulsion through the vent), slipping, and internal damage requiring an expensive rebuild. If you accidentally wind up overfilling your transmission during this procedure, simply allowing some fluid to be pumped out (or momentarily removing the drain plug from the bottom of the pan) will rectify this.
1992 735i
"Black Beauty"
Master Diagnostic and Repair Specialist
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The recommended transmission fluid is Dexron II. Dexron III is a suitable substitute. As for the 15W50 motor oil reference, this information is found in your owner's manual. Since I do this for a living, I also have information like this as well as repair and service information available to me at a moment's notice (have an automotive data base installed in my computer which is updated quarterly).
I can tell you an easy (but a little messy, not too bad though) way to do your own transmission fluid flush on virtually any vehicle WITH A DIPSTICK/FILLER TUBE ONLY. This is a safe and effective way of replacing the fluid in your transmission (torque converter and all) as opposed to 'dropping the pan' which only allows you to replace about a quarter to a third of what the transmission actually holds, since there is no drain plug in the torque converter. Simply remove the top transmission cooler line (this is the feed line from the trans for a BMW) from the radiator and attach a hose to that line running it into a bucket (one that holds at least as much fluid as you're exchanging). Then install a funnel to the transmission dipstick/filler tube. Our transmissions hold approximately 12 to 15 quarts of fluid, so have three to four 1 gallon jugs of fresh fluid on hand. Set the emergency brake, block the drive wheels securely (having an assistant to man the ignition, shifter and brakes would be ideal for this). Start the engine and put the transmission in gear, (not park or neutral since the pump in a ZF trans doesn't really circulate much unless it's in gear), start to pour fresh fluid into the funnel at about the same rate that it's being pumped out into the bucket until you've used up (and have pumped out) 3 or 4 gallons (depending on how much you are exchanging). By this time the fluid being pumped out should be nice and clean. Shut the engine off and re-assemble the cooler line to the radiator. I know first hand that this works because this is essentialy how it's done using a transmission flushing machine, and his is how I did it on my own E32 when I first got it.
***NOTICE***
**As with any DIY procedure, undergoing this is done at your own risk. Servicing your transmission is purely for maintenance purposes only and is not recommended for 'fixing' an already existing mechanical problem. It's best to drain and remove the trans pan so that you can inspect it for signs of internal transmission damage or failures. Should any signs of this exist (chewed-up metal parts or whole pieces of clutch material), then put the pan and the fluid you got out back and consider replacing or having the transmission rebuilt.
*If fluid begins to pump out of the fitting from the radiator when you start the procedure, immediately shut off the engine and install the hose on the radiator somehow, or on the other line at the bottom of the radiator. This is caused by a reversal of the fluid flow to the radiator from having lines reversed (either by design or mistake and poses no danger to the transmission or radiator (doesn't matter which direction fluid flows through the cooler, as long as it flows and is cooled)
*Do NOT perform this procedure on a 'sick' transmission which slips (check the fluid level first if it slips to make sure it's full), has alot of debris in the pan or is mechanically unsound.
*Do NOT attempt this procedure on a transmission which is not fitted with a dipstick tube, since you will not be able to pour fresh fluid in while the old fluid is being pumped out.
*Do NOT overfill or underfill your transmission. Doing so will cause foaming (leading to fluid expulsion through the vent), slipping, and internal damage requiring an expensive rebuild. If you accidentally wind up overfilling your transmission during this procedure, simply allowing some fluid to be pumped out (or momentarily removing the drain plug from the bottom of the pan) will rectify this.
1992 735i
"Black Beauty"
Master Diagnostic and Repair Specialist