My Final Drive went out

[Marty Hill]

Where do you get 4-5%? There are 12k or more members on this site and I recall 100 or less having the problem. Same ratio on adv. and ukgser. My guess is that 1% is a stretch.

[Twisties]

Hi Marty,

 

I know we'll never agree on this, but that's ok. As I say several informal, non-scientific polls. There is the famous one on the LT forum, www.bmwlt.com and there is this one here:

BMWST Poll

 

I believe I have seen one more somewhere, but two is enough for me for now.

 

As I said, my personal opinion is that they do run somewhat high, but I'm pointing out we have no evidence of that and the bias could be that they are low. We just don't know. There is no hard data.

 

Jan

[Twisties]

'd bet the real number is less than 1% failure rate (based on our local club, rather heavily populated by riders with the new drive - and only one failure experienced last year with over 300,000 miles totalled in our mileage context.

 

Let me add, this is far too few miles to make an evaluation. We can define premature FD failure a number of ways, but lets say, generously, that it means a failure at under 50,000 miles (though I'd personally use 100,000), then you would need a premature FD failure rate of 17% to expect one failure in your group, assuming that failures occur evenly in terms of miles on the bikes and that all bikes in the group are under 50,000 miles. On the other hand, the fact that you actually have one premature FD failure says nothing. Could have been luck of the draw.

 

To detect and quantify a 5% failure rate accurately, you would need something like 15 million miles.

 

Jan

[Don_Eilenberger]

Hi Marty,

 

I know we'll never agree on this, but that's ok. As I say several informal, non-scientific polls. There is the famous one on the LT forum, www.bmwlt.com and there is this one here:

Just a point here - the LT uses the old design rear drive - really data from that poll isn't applicable to hexheads..

BMWST Poll

 

I believe I have seen one more somewhere, but two is enough for me for now.

 

As I said, my personal opinion is that they do run somewhat high, but I'm pointing out we have no evidence of that and the bias could be that they are low. We just don't know. There is no hard data.

 

Jan

Agreed - no hard data.. just what I've observed with the riders I know. It isn't something to stay up nights fretting about IMHO.

[Don_Eilenberger]

Let me add, this is far too few miles to make an evaluation. We can define premature FD failure a number of ways, but lets say, generously, that it means a failure at under 50,000 miles (though I'd personally use 100,000), then you would need a premature FD failure rate of 17% to expect one failure in your group, assuming that failures occur evenly in terms of miles on the bikes and that all bikes in the group are under 50,000 miles. On the other hand, the fact that you actually have one premature FD failure says nothing. Could have been luck of the draw.

 

To detect and quantify a 5% failure rate accurately, you would need something like 15 million miles.

 

Jan

Jan - good point. Need more data.

 

One thing notable about the single failure - the rider first observed a problem somewhere in the west - and he then rode the bike home to NJ before it really started getting squirrely. A bit over 1,000 miles.. It was the seal failure, followed by the speedo/abs going out (sensor melted down from heat - this was out west, he hadn't seen the leak) - and finally it started binding up about 20 miles from home. He made it - slowly from that point.

[grasslander]

Where do you get 4-5%? There are 12k or more members on this site and I recall 100 or less having the problem. Same ratio on adv. and ukgser. My guess is that 1% is a stretch.

 

Disclaimer: unscientific...

 

Based on the potential number of Hex BMW units my dealer has sold against my failure (if mine is the only one they have experienced), the rate is probably less than a .5%. On the other hand, a BMW owning maintenance manager for a large multi-national company told me this week he is convinced that the rate is probably as high as 25%. The real problem is BMW's approach to fixing and no communication with anybody as to the problem (especially existing owners). Regardless the rate of failure, FUD (fear uncertainty doubt) IS costing them potential new unit sales. I certainly would think hard before plunking down $15-19k on another new machine.

 

Funny, when I purchased my first sidecar, the 1990 Russian Sputnik's owner manual stated that they were very proud of the fact that they now had wheel bearing failures to less than 1%. I promptly replaced the bearing with a western brand before the first ride!

[HexHead]

[ On the other hand, a BMW owning maintenance manager for a large multi-national company told me this week he is convinced that the rate is probably as high as 25%.

 

That's just nonsense.

 

From what I've heard, one reason for failures on LTs in particular is that they tend to be overloaded more often, pulling trailers etc. They may be big, but they still have GVW ratings that shouldn't be ignored.