What Do You Think the Odds of a Transmission Failure?

[lskbike]

I have a 1989 BMW R100RT that has been in storage for the two 2 years I have owned it. I have a few other bikes so I ride my newer F650GS(twin) rather than this older RT. I bought the R100RT from the second owner who also owned it for about two years but rarely rode it. It only has 35K miles on the odometer and has been well treated by the previous owner(s) and is in excellent condition. I am now retired and have been planning on returning it to the road as my primary "Traveler" next season and plan on riding it to many BMW rally's and MOA Get To Togethers. I expect to add from 5K to 10K on this bike over next summer. (I thought it would be cool for the Ole grey haired vintage guy to be riding an Ole vintage BMW.) I have always wanted an older Airhead and was under the impression by other Airhead riders that they are extremely reliable, especially if the ignition system has been upgraded. I have just come across information leading me to believe that the transmission in my bike is a "time-bomb" just waiting to strand me on the side of the road and cost me a ton of money. Apparently this is because BMW, considering their infinite teutonic wisdom, stopped machining a groove and installing a "circlip" at the end of my bike's transmission's "output" shaft. From reading on the internet, I understand will allow the bearing to eventually move cause it to bind and fail prematurely. It sounds like it is not just a matter of if but when it will happen. I have to say...I did test ride this bike before purchase and it started and rode well. I did not notice any issues with the shifting of the transmission. It seemed to shift well and it had no excess vibration or noises!

But now, because of the lack of this "circlip" in it's tranny, I am considering my options, as I understand that there isn't much prior notice of impending doom before the transmission "grenades". When this happens it will leave the bike on the side of the road with an expensive tow needed, expensive shipment home (or to dealer..NaW Never there) and then to install a very expensive rebuilt transmission… all which would cost much more the bike is worth.

With this in mind… Anyone out there know the odds of my bike lunching it's transmission? Can anyone share their personal experience with the "circlip" issue? Any Recommendations for businesses that can do this work for me? Anyone know about how much it will cost to do this work? (I have heard it can cost up to $1,500) All information that those with experience regarding this issue and Airhead issues (both negative and positive) in general can provide will be greatly appreciated.

My options:

Leave it sitting in my garage as an Object De Art!

Part it out!

Ride it until there is some indication there is a problem then repair... or if the transmission dies then part it out!

Pull the transmission and have it corrected and then ride into the setting sun happily forever!

I am leaning toward pulling the transmission and sending it off for inspection and groove cutting with the clirclip installation. BUT I certainly don't want to spend the time and dollars doing this if this is more of the typical internet scare type information when the odds of this transmission failure are very low.

Thanks in advance for your input…. All would be appreciated…

Remember Brother Airheads... "Simple by Choice" …

LSKBike
Southeastern Indiana

[khittner1]

LSK---With only 35k on it, your worries seem overwrought. Drain your oil, check the drain plug for metal bits (rather than a reasonable amount of smooth, fine powder deposits that are OK), refill with Amsoil Severe Gear synthetic 75w-90, repeat every 10K, and ride it for another 35-40K. Then, or before Cutter or Porter announce their retirement plans, whichever is earlier, get your rebuild done. This is my plan, anyway. If I end up with my airhead RT as an art object in my garage, I'll have ante up for one of those new-fangled K75 bikes . . .

[Ken in Oklahoma]

For whatever it's worth I have a '91 R100RT with 87K miles on the transmission, and the transmission is working just fine. (My transmission also doesn't have the circlip.) So subtracting your miles from mine might give you a measure of confidence. You might very well have a different problem showing up in your transmission before a lack-of-circlip failure. Consider that there are other parts in your tranny that can and do fail, which will require you to open it up. If one of those other problems should show up first then you can have the circlip groove machined as a matter of course.

Another alternative would be to buy a known good transmission and put it on the shelf against the time when you present transmission might fail. Duane Ausherman, who posts here, has informed us that the 5 speed transmissions are significantly more prone to fail than the old 4 speeds were. I have laid in a couple spare transmissions for my earlier airheads against the time when I will surely encounter a transmission failure. Coils, alternator rotors, diode boards, voltage regulators are all good parts to have on hand.

Even though a spare transmission is spendy the comfort you will have with a spare on hand will be money well spent. And you will always be able to sell your spare transmission for more than you paid for it if and when you ever sell your RT.

Your philosophy may vary.

Ken

[ME 109]

With this in mind… Anyone out there know the odds of my bike lunching it's transmission?

Your tranny won't grenade due to a missing circlip.
The front output shaft bearing can move forward and the fifth gear next to the bearing is able to develop radial play which damages the shaft where it rides, and that radial play allows the gear to run out of true, damaging the other helical gears.

Then there is the separate issue of front output shaft bearing failure, which also creates misalignment of the 5th helical gear and damages the other helical gears, and other components, as the failure grows.
The tranny jumping out of 5th gear seems to be the first symptom of a badly failed bearing.

The magnetic plug is your best early indicator of what is happening in the box. Black slime is ok, lots of fuzz is not.

The big names of airhead repair are the places to send the output shaft for repair. They do it a lot, and know what they're doing.
If you're unable to fix the rest of the tranny yourself, things do get expensive.

[lskbike]

Thanks everyone for UR great advise…. THE PLAN: I will maintain the lube in the transmission religiously and will pay close attention to the magnetic drain plug. I will just ride the bike and will not worry about it until there is some indication of a problem.

My philosophy is pretty much the same as yours Ken... so I'll be stocking up on the various "spares" recommended for R100RT's, including working on finding a good used transmission. If I find one, I will probably tear it apart so I can learn how they they work. Of course, I will then replace or repair any worn parts including bearings. As I can't do the machine work in my home shop, I will send the output shaft to one of the experts for machining the groove and to provide me the correct circlip. Once put back together, I will probably install it in the bike then rebuild the original transmission to go on the shelf for future use.

I just love doing stuff like this…

Thanks again guys… See ya on the road…

LSKBike
Southeastern Indiana

[SteveD]

Lots of great advice.
Ride it, watch it and then if and when you need to...there's this..viewtopic.php?f=1&t=9281
I'd wager you'll have someone local enough to help you with tools and knowledge too.

[daz]

I have a 1989 BMW R100RT I am now retired and have been planning on returning it to the road as my primary "Traveler" next season and plan on riding it to many BMW rally's and MOA Get To Togethers. I expect to add from 5K to 10K on this bike over next summer. (I thought it would be cool for the Ole grey haired vintage guy to be riding an Ole vintage BMW.)

LSKBike
Southeastern Indiana

Serious? You'd be hard pressed to fine anyone other than old codgers. Well, I guess some of the guys dye their hair! Well, those lucky guys that still have some.

[PAS]

DAZ, I'm an old gray codger that rides an 81 RT! There's still a few of us left. As far as the transmission goes. A friend put well over 100K on his 95 RT with no rebuilds at all. I dont know if it had the groove or not.

[Duane Ausherman]

"(I thought it would be cool for the Ole grey haired vintage guy to be riding an Ole vintage BMW.)"

That isn't an "Ole vintage BMW" by any stretch of the imagination.

Ken, that bike is 15 years newer than those of my day. Nothing that I ever said applies to a "new' model like that

I know nothing from personal experience about that groove for the clip, only what I have read.

If it were an older model, I would suggest changing oil and examining it very closely. Then I would ride it for at least 500 road miles and drain the oil out while hot and once again examine it carefully. If the oil shows a "sheen" in sunlight, I would repeat it for another 500 miles and hope to get lucky.

Since it isn't an older model, I know nothing about it.

[Ken in Oklahoma]

Since it isn't an older model, I know nothing about it.

Duane, I'm going to call a B.S. on that. First of all, how close in function is the latest airhead BMW made to the earliest /5 or /6? Would you say 80% or 90%, or even 95%? Secondly, though hands on experience is really good to have, your greater tool is your brain and a thoughtful purposeful approach to any problem. Thirdly, you have even created a web site so that your knowledge will outlive you. That ain't nothing. You don't have a disclaimer on your website saying that if your airhead is later than a /7 go look somewhere else for the information you need.

So there, take that!

Ken, spluttering in Oklahoma