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Final Drive Oil Capacity
- Thread starter LCampbell
- Start date
Norms 427
Norm
I'm new to BMWs but I've read in a few places that they've reduced the amount from 240 ml to 180 ml. I've also read it was done in May '09. The Maintenance DVD also specifies 180 ml.
Why did they reduce it? I've read a couple of speculative reasons but I'm not sure if they're the official reasons or not. Maybe someone can chime in.
Why did they reduce it? I've read a couple of speculative reasons but I'm not sure if they're the official reasons or not. Maybe someone can chime in.
patiodadio
Motorcyclist
So, how often should we replace the fluid, since its a lesser amount ?
PGlaves
#13338
You more or less have to follow the entire history of these drives to understand the chain of events. Then deductive reasoning (not pure speculation) can provide pretty strong clues as to why they did it. It is unlikely they will post in a bulletin why they did it. If they do it won't be here.
They started out with sealed, pressure vessal, lubed for life, drives. They found that swarf from the manufacturing process was still inside so declared the oil should be drained at 600 miles. Since there was no drain plug they said it should be swung down 90 degrees and drained through the fill hole. Many dealers also advised it ought to to changed every 12,000 miles. After a while BMW agreed and specified the 12,000 mile interval. They also added drain plugs. Meanwhile the drives had fairly frequent seal failures. Oil simply got pushed past seals. If not noticed and a drive lost enough oil then they got hot and bearings and gears were destroyed. At least one caught on fire. BMW didn't change the seals as far as I can tell but they did reduce the volume of the oil. Finally, they equipped the new drives with vents.
From the sequence of events it is obvious that they were concerned about the pressure build-up inside the drives as they heated up. Reducing the volume of oil which is not compressible and increasing the volume of air which is compressible could serve to reduce operating pressures. Finally adding a vent closed the circle of events.
We are now back where we started with all the older style drives: 600 mile change, 12,000 mile change interval. Drain plugs. Vents.
+1
Its been interesting to see how slow BMW has been dealing with a simple issue and that the result has simply been to undo the original hexhead design flaws in the FD in a series of steps rather than a single effective change.
The drives get pretty warm even in ideal circumstances- hardly a surprise when you stir a fairly viscous lube rather vigorously with small gears. With that heat added to the drive one is already heading down the path to problems (though normal operating temps are a bit more than 100 degrees lower than what can be expected to cause problems) so anything that keeps heat under control and pressures down is a good thing. That's one reason why those decorative rings closing the big hole are a lousy idea- they just block air flow and heat radiating from the drive hub.
IIRC somewhere along the way a bearing got upsized a little and that never hurts durability.
I do FD lube changes when I do rear tires and never go more than 12K- sometimes every tire change- hoping to spot issues soon enough to get by with a simple fix rather than a $2K bill. (As much as I hate chains, one can buy a small crate of chains and sprockets for that kind of $ and at typical prices/durabilty for such that $2K represents something like 200,000 miles of chain drive costs)
Now if they'll just undo the design goofs in the fuel system in a complete manner.
1) New fuel tank molds with self draining wells, if wells are used, and proper design and gasketing to protect electrical parts from water penetration
2) More durable and better designed quick disconnects (see any of the types commonly used in auto racing)
3) No plastic pipe thread fittings for fuel containment- dumb idea no matter what plastic you pick- again, look at auto racing examples for quality light parts designs.
Note that there are at least 2 aftermarket reinforcing parts available to address the this elementary failure of material selection by the factory and that the factory fix is simply a copy of one of them added to the old design.
4) A decent fix for previous goofs like the fuel strip "system"
In the case of the fuel system one wouldn't want to go backwards in BMW history. Many of the previous models are also poor designs from a safety and maintenance standpoint with stuff like internal filters and hoses that split, large ports to access the previous sealed only by an O ring, etc etc.
Its been interesting to see how slow BMW has been dealing with a simple issue and that the result has simply been to undo the original hexhead design flaws in the FD in a series of steps rather than a single effective change.
The drives get pretty warm even in ideal circumstances- hardly a surprise when you stir a fairly viscous lube rather vigorously with small gears. With that heat added to the drive one is already heading down the path to problems (though normal operating temps are a bit more than 100 degrees lower than what can be expected to cause problems) so anything that keeps heat under control and pressures down is a good thing. That's one reason why those decorative rings closing the big hole are a lousy idea- they just block air flow and heat radiating from the drive hub.
IIRC somewhere along the way a bearing got upsized a little and that never hurts durability.
I do FD lube changes when I do rear tires and never go more than 12K- sometimes every tire change- hoping to spot issues soon enough to get by with a simple fix rather than a $2K bill. (As much as I hate chains, one can buy a small crate of chains and sprockets for that kind of $ and at typical prices/durabilty for such that $2K represents something like 200,000 miles of chain drive costs)
Now if they'll just undo the design goofs in the fuel system in a complete manner.
1) New fuel tank molds with self draining wells, if wells are used, and proper design and gasketing to protect electrical parts from water penetration
2) More durable and better designed quick disconnects (see any of the types commonly used in auto racing)
3) No plastic pipe thread fittings for fuel containment- dumb idea no matter what plastic you pick- again, look at auto racing examples for quality light parts designs.
Note that there are at least 2 aftermarket reinforcing parts available to address the this elementary failure of material selection by the factory and that the factory fix is simply a copy of one of them added to the old design.
4) A decent fix for previous goofs like the fuel strip "system"
In the case of the fuel system one wouldn't want to go backwards in BMW history. Many of the previous models are also poor designs from a safety and maintenance standpoint with stuff like internal filters and hoses that split, large ports to access the previous sealed only by an O ring, etc etc.
New tire equals FD oil change in my personal book. Randy
RT290
New member
Official service manual states 180ml in final drive changed every two years or 20,000km.
Joel
easy way to measure and add final drive oil
I purchased a 60 ml syringe at a Tractor Supply store. Place about 4"length of clear plastic tube, over the needle nozzle. Draw up oil into syringe then bleed bubbles by placing nozzle and tube up pushing plunger till air is gone.
Now fill the tube to 60 ml mark. Insert hose into fill hole through gap in brake disc. (rear wheel removed at this point) As you empty the syringe take your time and make sure the hose is not blown of the syringe by holding on to it while pushing the plunger.
Three discharges of syringe will complete the refill. No spill, no mess, pretty precise quantity.
I purchased a 60 ml syringe at a Tractor Supply store. Place about 4"length of clear plastic tube, over the needle nozzle. Draw up oil into syringe then bleed bubbles by placing nozzle and tube up pushing plunger till air is gone.
Now fill the tube to 60 ml mark. Insert hose into fill hole through gap in brake disc. (rear wheel removed at this point) As you empty the syringe take your time and make sure the hose is not blown of the syringe by holding on to it while pushing the plunger.
Three discharges of syringe will complete the refill. No spill, no mess, pretty precise quantity.
