Took a ride with SO for about three hours this morning. Temps in the low 80's. When I got back I took my infrared temp gauge and the temps on the bottom of the FD was 133F, the middle was 134F and the top of the FD was 135F. For shits and giggles I also checked the Crankcase cover and the valve cover. Both were around 155F. Someone here mentioned that there is a way to check if the FD was in distress by putting your hand on it. If you had to pull it off immediately that was not good but if you could hold your hand there for awhile that it was OK. That temperature testing method was pretty subjective. For instance Saddleman probably doesn't wear welding gloves because his hands are like leather, compared to my supple pink well manicured girl hands that an ice cube would burn me. So I'm curious what actual temp would be considered normal. If enough people can check their FD's temp and post those we may be able to determine a target temp that says your FD is OK and then also a temp rise target that indicates your FD is on the way out.
What are your thoughts on this or is it a waste of time.

I don't know exactly what temp is acceptable. However the PO of my bike had the FD rebuilt and had a temperate warning light installed. According to the notes on the bike, the light is suppose to light at 137F.

Not a really good indicator except for a short ride. I have tire/wheel temps on the order of 168 for the rear (SmarTire unit give temps) in the summer. This can easily transfer to the drive through the wheel. Best preventative is frequent oil changes (same as engine) and monitor the oil for shiny stuff (bearing) and darkness (aluminum from spinning bearing).

Just returned from a 2,250 mile trip to CO. Air temps were as high as 98F, which was lower than I expected. The warning light never flickered. So, to me it seems 137F is "hot" for an FD.

I had a ride from Cleveland, OH to Idaho, one year, and had 113 degrees to North Dakota. The FD, on my 99 LT, had 30,000 miles on it, at the time. On my return trip home, Cleveland, 100 miles from home, the FD gave out. One could relate the temperature to the failure or just say it was a coincident. Not having a temp. gauge at the time, I do not have the actual temperature, though.

I did the Saddleman test after an hour ride. Got cool enough that I needed a lite jacket on the way home. Everything was hot back there but I was able to hold onto to the final drive for several seconds. No leather on my hands. Annual fluid changes regardless of the millage just to keep an eye on it.

+1 John, don't obsess over the final drive, just ride and have fun.

Worrying about it won't keep it from failing, just do like John says as far as maintenance goes and enjoy.

later...Randy

Hi, after my last FD repair I put an external temp sensor on it. Last week, and this is after ~1000 km after repair, I rode for about 130 miles on a tough tempo like 120 m/h, the max temp I read was 134 F.
I can tel I pushed my LT hard but I needed to see how it does. Amb temp was ~80 F.

I recently took a 2up ride on my 2001 and when I got back, tried the hand test and it was hot enough that I didn't want to keep my hand on it for more than 2 seconds. I don't have a IR gauge in my tool set yet but it was hotter than I think I would like it to be. I have purchased the crown bearing and seal and am going to do a preemptive rebuild in the next couple weeks. I have no maintenance records from PO's so it could easily be an original bearing with 52K and in the questionable range for date and milage. Thanks to CharlieVT for the PM's and his video of the process or I may not have decided to undertake it on my own. I am going to try and take some good pictures as it isn't a failure yet with measurements done by the Dman process and see if it comes out to be over shimmed or in the proper range. At least it will give me peace of mind on the FD status.

+++++ 1 Your right,I have ALOT of miles on the same FD. Do the oil changes and ride on. keep the rubber side down.

Zeke

I don't recall exact figures now, but I believe the 18 wheelers I used to drive ran 160 F and higher quite routinely. I wouldn't worry much about 137 or even 150.

Then again, I think most LT FD bearings fail due to fatigue from too high a preload and not due to friction (sliding motion between parts), so I am not at all convinced that FD temp is a good condition indicator for an LT final drive. Maybe for the small bearing spinning failure, but not the large bearing failure.

Great words: Keep the rubber side down!!!

Gentlemen, whatever we say, BMW failed on this FD but they got away and never recalled to pay off their mistake. Their design failed. Why they did not use a two row bearing to cover the loads on the FD initially?

A buyer here in Greece suffered so much that can't be told. I will try to locate his story in the blog I saw it time ago and give you the main point of failures he had to suffer on an LT.

I would not say BMW failed on this FD. BMW failed in putting this FD on LT. Same FD works OK in lighter K- & R-bikes.

Yes, the evidence is pretty good that the K1200LT final drive failures are a result of machining and assembly errors. The problems are not an engineering/design issue.

The thing that pisses me off is all the other engineering failures that vehicle manufacturers get away with because they don't qualify as a hazard. We pay through the nose to have those corrected out of pocket if not picked up under warranty, which seems to be the norm. Unfortunately brand loyalty is not what it use to be because very few manufacturers truly stand behind their product anymore. We tend to stay with the products that causes us the least issues. With instant feedback on the internet, companies need to pay close attention to reviews because many are swayed by them. I always write reviews on products that do not measure up. Again the arrogant bastards make so much profit anyway they continue on sticking it to the consumer.

Sorry my rant was on.

The nuances of BMW motorcycles (and cars) is not 15 years old or less. I don't recall BMW ever being known for reliability. Why in the world would we expect it now or expect them to "stand behind" their product? If you bought a BMW, you should expect interesting (and expensive times).

I have repaired several other model bikes with the same style FD that failed just like the LT's did.

We probably don't have data on this but has anyone who does these rebuilds keep track of what shims were in the FD before the rebuild?

Just wondering if someone at an assembly plant decide that to save time, the average shim we use is say for argument sake, .6mm and we will just put that in all of them and that will save time on assembly?

If a large number all had the same shim and were over shimmed......

Hind sight is always 20-20. Would not make any difference now but if we had that data, it may show a pattern of possible assembly without the actual measurement having been taken leading to this early failure trend.

I bet CharlieVT and Saddleman both have records.

Personally, I think anything is possible, but this is an unlikely scenario. I would suspect the following as the more likely causes:

1. Workers not properly trained or competent for this procedure.

2. One or more assembly fixtures or tools that were a little out of spec.

3. Improper specs provided to manufacturing from engineering.

The factory shims vary a lot.

If that is the case, then it is down to what Voyager said. Was curious on that bit of data. Thanks for responding Dave.

Any tips on crown replacement as I plan on doing mine next week preemptively other than driving it up to you when I fail ?

Watched CharlyVT's video and it looks straight forward enough and I have the tools for it. Peace of mind replacement as I ride 2 up most of the time on what is likely original and 52K, hoping I see no other issues inside. Asking because on several occasions you have quoted having a large number of hours spent on a single final drive.

If you are confident it is still the original crown bearing I would just replace it. If you don't know the history of the FD I would recommend a rebuild.

A Saddleman rebuilt drive is the best peace of mind. On my way to Billings for the National, no worries other than other drivers.

Robert

I have no mechanical history on this bike. I see evidence that it was maintained pretty well but there is no warranty history of it being done so I will have to wait till I get the cover off to know if there is any abnormal wear or issues. I will inspect it carefully and if a rebuild is warranted, I may need some better procedures to accomplish that. I have the BMW manual and the Clymer however, I have never set up a ring and pinion before for the proper contact pattern and experience counts in that area so I would consider having that done and all shimmed and set up properly with all new seals. Should I decide to go that route, I will contact you for scheduling and you are close enough for me to take a drive and drop it off if that would be agreeable. Plenty of antique shops along the way to make the drive worth it. I will know when the covers are split.

I just measured 51degC and could hold my hand on middle (driveshaft area) for a few seconds. I thought it was pretty hot! (124degF) that was 45min two-up ride 3/4 thru city.

I am not sure what is normal for an LT, but when I drove OTR trucks, 160 F was common to see in rear diffs and on a 100 F day pulling a long hill, 200+ wasn't unheard of. I think most gear oils are good for at least 240.

Really?
My 85 k100rs I got with 60k miles 20 years ago, currently the plus side of 350k. The most dependable and reliable motorcycle I have ever owned! and I have owned most of them
Regular maintenance, a few water/oil pumps, and speedometers, cables, brakes, and tires.. lots of tires .

I guess I got lucky

After 875kms on rebuilt FD its leaking oil. I'm trying to determine if it's the bearing seal or the breather thingy on the top of the FD that's the source of the leak. Wiped it all off and check again.

Who rebuilt it and what method did you use to do the shimming? Hopefully, it is just over full and blowing out the top. 875kms is about 550 miles ( unless reading that wrong). Not a lot of miles to cause another failure unless it was grossly over shimmed. Can you detect any play in the rear wheel that can't be attributed to the pivot bearings?

That was back when BMW focused on relatively simple, reliable machines. When they got on the technology bandwagon in the 90s, reliability was no longer a priority. I am no Luddite. I spent my entire career in engineering and R&D at a Fortune 500 company, but I also know that with proper engineering and manufacturing you can have reliable technology.

I owned three Kawasaki bikes from a 1973 100 to a 1987 Voyager XII. They were quite reliable and required little maintenance (hydraulic lifters are VERY smart on a touring bike engine). I got my LT after Kawasaki dropped the real Voyager line and moved to the Harley wannabe Vulcan Voyager. The LT is a superb machine from a comfort and performance perspective, but is a maintenance and reliability nightmare. Annual brake fluid flushes. Really? Removal of fuel tank to access relays and air filter. Seriously? Bucket style valve adjustments that take several hours of labor and typically at least a week waiting on parts? And that is ignoring the serious flaws like FD, transmission input bearing, clutch slave, dry clutch that doesn't stay dry, weak trunk latch, and on and on. If a bike even close to the LT in comfort and performance is released, I will switch in a heart beat ... especially if a Japanese name is on the tank!

Hmmm... well Shail's BMW rebuilt it 4yrs ago... however, I noticed lots of oil around the breather on top so I cleaned all the oil off it, drained, refilled fresh oil. Popped the breather off, cleaned. Rotated so little hole faced outward.

Got to work this morning no leak. WEIRD! I'll be keeping my eye on it that's for sure.

How much oil did you put in? You want to fill with 220 ml. Do not fill to the bottom of the fill hole as with most gearboxes. This will leave insufficient expansion room.