How hot?

[Shep]

Has anybody noticed how warm their final drive gets after a few miles, I thought I had rear drive problems last night/this morning (see sep thread) when i checked over the bike, I noticed that it was uncomfortable to hold my fingers on the rear axle shaft (the hollow bit) I'd done about 60mls, the last 30 of which were at 70ish on dual carrageway, it was hot enough for me to think the rear brake may be dragging, but that was OK.

The dealer, on checking over the bike, found a loose/broken hugger support arm. Claimed this was the reason for the droning vibration /roughness I was getting on the overrun, which is possible I suppose, then when I said I had found metal in the rear drive oil, he said they all do that sir! Then when I questioned the hot rear axle, same answer, they all do that sir!

Do they?


Help me out,

Shep

 

[Mouse]

I changed my rear drive oil after about 15,000 miles. It was black and syrupy, and smelt absolutely foul. But there was no evidence of either metal particles or water contamination (which was what I was worried about).

On the other hand, when I changed the gearbox oil, there were sparkly metal particles in there, but extremely fine ones that you might expect from a "running in" box, so I wasn't overly concerned.

Haven't groped my rear axle recently, sorry! Will try and remember to do so.

 

[Boz]

Am I wrong.... but I thought you didn't need to replace the final drive oil? Thought it was good enough to last the life of the bike, or am I getting confused with another part of the bike?

Nik

 

[Shep]

I changed my rear drive oil after about 15,000 miles. It was black and syrupy, and smelt absolutely foul. But there was no evidence of either metal particles or water contamination (which was what I was worried about).

On the other hand, when I changed the gearbox oil, there were sparkly metal particles in there, but extremely fine ones that you might expect from a "running in" box, so I wasn't overly concerned.

Haven't groped my rear axle recently, sorry! Will try and remember to do so.

Hi Mouse

Thanks for that

What did you replace the oil with?

How did you drain it out? I did'nt notice a drain plug & I can't check at the mo as its at the dealer.

Shep

 

[tiller269]

Boz is right. They are supposed to be sealed for life. Before you get too worried, you have to remember that you have a shaft and gears in there rotating at speed in a bath of oil. It's bound to get hot! Remember those days when we used to ride around on bikes with chains? If you touched the chain after a 'spirited' ride, you would have got burnt fingers!

 

[Mouse]

What did you replace the oil with?

How did you drain it out? I did'nt notice a drain plug & I can't check at the mo as its at the dealer.

The oil to use is Castrol SAF-XO, the same as used for the gearbox.

The drain plug is at the back of the final drive. To drain the oil you have to disconnect the telelever arm from the FD (with the rear wheel off obviously) and allow the FD to tilt backwards to drain the oil out. Beware - it's damn heavy.

When reassembling you have to "wiggle" the spline son the drive shaft back into place. It's a bit fiddly, and probaby easier if you have someone or something to support the weight of the FD.

Then use the ABS sensor hole to refill. Capacity is 250ml.

 

[Mouse]

BMW claim the FD is "sealed for life" but having seen the state of the oil that came out of mine, I don't believe them

Nothing lasts forever anyway, if the gearbox oil only lasts 24,000 why should the same oil in the FD last for ever? Of course by "sealed for life" they mean the design life of the bike, which for all we know could be 50,000 miles!

 

[Chris Terry]

I think BMW mean sealed for the life of the warrantee, but if it makes you feel better changing the oil why not.

 

[Mouse]

At about £3 for the oil required and a couple of hours of my time, I look on it as cheap preventative maintenance

 

[Shep]

Copied from the other post:

Great news,

No problem at all with the final drive, all the metal particles in my oil sample were from swarf trapped in the level plug area, they found no metal at all in the rest of the oil they drained out. All the grinding/howling noise was caused by the loose/broken hugger!

But they've decided to change the rear drive, to restore my confidence in their product!

Nothing at all to do with the sample of oil I have in my possesion with bits of metal floating around in it that I showed to their mechanic from BWM assist when they picked up the bike, (enough to convince him to recover the bike) I also showed the same sample to an engineer friend who agreed there was alot of swarf present, especially for the low milage of the bike.

Still at least i'm confident now!

Shep