monolever reliability

[f14rio]

i have read several items that say the monolever system on the post '86 r bikes (same as on k bikes, i think) is the least reliable of the bmw drive systems. has anyone here had any experience to verify this?
if so, what kind of preventitive maintenence might be recommended?
thx,
ed flanagan
('87 r80)

[88bmwJeff]

From what I've heard, many people think the monolever set up is the best. Are you sure people weren't talking about the first generation paralever on the GS and R? The drive shafts on those have a relatively short lifespan.

[f14rio]

i have about 18k mi on mine.
...
aggie humor follows:

A young Texas Aggie volunteered for military service during World War II. He had such a high aptitude for aviation that he was sent right to Pensacola Naval Air Station, skipping recruit training. The very first day at Pensacola, he solos, and is the best flier on the base. All they could do was give him his gold wings and assign him immediately to an aircraft carrier in the Pacific. On his first day aboard, he took off and single-handedlyshot down 6 Japanese fighter planes. Then, climbing up to 20,000 feet,he found 9 more Japanese planes, and shot them all down as well. Noting that his fuel was getting low, he descended,circled the carrier, and came in for a perfect landing on the deck. He threw back the canopy, climbed out, and jogged over to the captain.Saluting smartly, he said, "Well sir, how did I do on my very first day?" The captain turned around, bowed politely, and replied,"You make onry one velly, velly selious mistake, yankee pierot."

[osbornk]

I thought they lasted forever. It has 50K on it and and mine has been with me for only12 years.

[130262]

I think you must be mixed up with the paralever.My 1987 R80RT has well over 100,000 kms on it. There are no rear wheel splines to wear out if you forget to lube them . The wheel bolts directly to the rear drive.Great models.
Bruce

[wecm31]

hmmmmm.... I was also of the understanding that the basic monolever was as robust as they come. Then I was just reading in the April issue of BMWON that the rear drive splines on the monos are problematic:scratch

I have always changed out both the drive shaft oil and final drive oil every year, but I have never taken off the actual rear drive to lube any internal splines. I assume its just behind the four bolts connecting the swing arm to the final drive, who has been down this road???

My 85 mono has 100K miles, no issues so far (and ASFAIK no drive spline lube!!)

gurus, kindly step in:lurk

[20774]

Do the monos even have rear wheel splines? I didn't think so as the wheel bolts directly to the final drive hub.

[mneblett]

Do the monos even have rear while splines? I didn't think so as the wheel bolts directly to the final drive hub. No wheel splines, but driveshaft-to-final drive input splines.

wecm31 -- I'd suggest re-reading Paul's article -- it's the *K-bike* monolever driveshaft splines that have had problems. As noted in the article in the paragraph just before the K-mono section, the airhead twin-shock and monolever shafts are located in oil baths, and are quite reliable.

[PGlaves]

i have read several items that say the monolever system on the post '86 r bikes (same as on k bikes, i think) is the least reliable of the bmw drive systems. has anyone here had any experience to verify this?
if so, what kind of preventitive maintenence might be recommended?
thx,
ed flanagan
('87 r80)

They are NOT the same as the K bikes. The Airhead monolever shaft still runs in oil in a wet cavity, avoiding the problem of wear at the rear of the shaft common on monolever K bikes. Whoever wrote what you read about this being a problem on the Airheads was simply misinformed. The problems on the Airheads are twofold: the wheel splines wear on the twin-shock models; and the universal joints fail on the Paralever R100GS models.

[wecm31]

Thanks Mark and Paul for the clarification. I think I too was confused as to what was common to the early K-bikes and the monoshock Airheads. I'll ride on with my oil changes confident that one less demon lurks in the shadows:thumb

[toooldtocare]

One caution though. My first BMW was a new 86 R80RT that I got late in 85. During my first service I drained the rear end oil, then removed the level plug and fill plug and poured in fresh 90W gear lube. I stopped when oil started coming out the level plug.

During the next service when I drained the oil I got almost nothing out, but what did come out was black and full of metal filings. A few thousand miles later the rear end started leaking oil from the big seal on the inside of the wheel.

BMW rebuilt the unit and told me that the mail bearing had failed. Thanks BMW. I figured what had happened was the oil ran down the ring gear and some of it ran out of the level plug instead of going into the bottom of the housing, which of course is when I stopped adding it. This resulted in a very low level causing the bearing and seal to fail. Moral of the story, measure the correct amount instead of using that level plug.

Other than that, this bike never gave me anymore trouble, nor did my other two mono-shock models (88RS and 95RT). I have also never talked to anyone that had any trouble with theirs either.

[88bmwJeff]

f14rio,
Sorry for the long delay, but didn't initially see your question in the header.

My RT has about 105k on the clock. I purchased it with about 88k. I have had to do some of the usual repairs. Tranny at 88k due to bearings, and final drive due to seals. At about 20 years, the seals were hard and brittle. Besides the seals, there was nothing else wrong. The PO did a valve job around 80k. Overall, the bike's running pretty good for a 22 year old bike.

With 18k on your ride, it's got plenty of life left in it.

[mchaven]

Nothing real to add here, just glad to see my Monolever is so reliable :) Only problem I've had with it was operator errors!

[92r100rs]

The monolever RS is the perfect reliable retro ride. Stupid GS tuning of the motor is the only flaw.

[88bmwJeff]

Only problem I've had with it was operator errors!

You had to bring up operator errors-----didn't you.


Well I'm taking the 5th here. :whistle

[beemerguru]

I've seen airheads with 200K miles on the same monolever drive shaft. My G/Ss and past K all have gone 100K with no issues. Just do the splines regularly and they just go and go and go.....