Transmission suddenly won't shift on 1994 R100RT

[811]

Been a MOA member since 1972-hence the 3 digit member number-but my first posting, so please forgive me if i ramble a bit. On my way to the Fontana rally yesterday my 1994 R100RT (78k miles) suddenly would not change from 2nd gear. The external linkage if fine and moves smoothly but does not shift up or down. Something internal obviously failed or came loose-feels like there is no connection inside. There were no abnormal noises or shifting issues prior to the failure to shift. All drive line fluids were changed 200 miles earlier. The oil from the transmission was clean with no debris/particles on the drain plug. Used BMW 20W50 dino oil in engine & Castrol 80W90 gl5 limited slip in tranny, drive shaft & final drive-all the same as I have been running.
Since this appears to be one of those that should have the "circlip modification" done and it has 78k miles on it, should I just figure on having it gone through instead of just the shifter repair (if that is all that has failed). I do my own light work but have never tried pulling the transmission or lubing the input splines. I'm confident that I can do the pull & reinstall but wonder if putting it into the shop would be better, so the whole bike could be evaluated. I've noticed of some good references for places to send the transmission to for rebuild. I'm close to a BMW dealer on the north side of Atlanta & about 60 miles from Apex Cycles in Ellijay, Ga. The dealer has an airhead guy & Apex got a good writeup in the MOA news some time back.
Any input from you more knowledgeable folks on what I can check or direction on what to do would be greatly appreciated.

A side issue; my voltmeter is not stable-it fluctuates rapidly most of the time. Have had no issues with the charging system not working. Don't know if I have a problem or maybe the meter is supposed to be dampened more that it is.

A plug for Platinum level membership: I called roadside assistance and about an hour later Eller's Fuel & Wrecker from Robbinsville, NC was there to pick me up (I was just south of Murphy, NC). He brought me some 90 miles home and it cost me zero dollars. What a great benefit! He was good company on the trip home as well. Kudos to BMWMOA Platinum membership and Ellers.

 

[20774]

Welcome, Jerryb! Yup, that MOA number gives you a bit of seniority!

My first thought was the issue with the circlip. Anton has a good description of the problem and symptoms. Before you go off to have that looked at, run through some of the steps to see if it suggests this as a problem. Seems like you would have seen something on the drain plug if the bearing was disintegrating.

http://www.largiader.com/articles/circlip/

But it could be the failed pawl spring. Snowbum has a discussion about it here:

http://bmwmotorcycletech.info/emergency-shifting-tool.htm

That only helps you get a more usable gear back if you are on the road and certainly if you've made the tool up ahead of time.

One thing you could also do is verify that the clutch is working correctly. Check the adjustments, movement of the rod at the back of the transmission, etc.

It would seem that the transmission is going to have to come out to be looked at, or maybe there's an issue with the clutch. Pulling the transmission is not a big deal, just a few steps in a sort of puzzle. It would be less costly in the end if you can get the tranny out yourself and then get it to a good repairman.

 

[811]

Thanks for the quick reply. Typed on the back of my first membership card was a note that I was the first member in the state of Georgia. I lapsed membership for a number of years, opting to concentrate on marriage and children, but am happy to be back.

I had read about that shift pawl spring back when and that's where my mind went pretty early on. The clutch feels, moves & disengages normally. Wonder if I should figure on a new clutch disc while the tranny is out?

What special tools will I need to do the tranny & clutch R&R? I know I'll need to order a thin walled socket for the swing arm nuts but not sure of what else. Is there a good 1-stop source for the tools? I'll need lube for the clutch splines as well-any recommendations on the grease & a source?

The timing is lousy because of the riding season, but I ride year 'round down here anyway, and it'll be expensive but I'm kind of looking forward to stretching myself a bit also.

 

[20774]

The clutch feels, moves & disengages normally. Wonder if I should figure on a new clutch disc while the tranny is out?

Well, at 78K, it's something to consider. If you had the time, remove it and measure and then decide...but sometimes we don't have the time.

What special tools will I need to do the tranny & clutch R&R? I know I'll need to order a thin walled socket for the swing arm nuts but not sure of what else. Is there a good 1-stop source for the tools? I'll need lube for the clutch splines as well-any recommendations on the grease & a source?

The socket is 27mm or 1-1/16"...they're available for purchase with all of the issues taken care of. Cycleworks is probably the best place to check out some of these special tools. You're going to need a torque wrench to reset the swing arm pins and bearings properly. I'm not sure about the 1994 clutch pack, but I don't think there's much in the way of special tools. The older clutches had stored energy that needed to be relieved before getting at the clutch. As for a transmission, my suggestion is to ship/deliver it to an Airhead mechanic who can do this work. There are some very special steps needed to get into the box and then it must be properly shimmed. I'm not familiar with the shop you mentioned. But Nathan at Boxerworks-Service in Watkinsville is someone to look into. There are people you can ship it to, but that might be more than you want to take on.

 

[Darryl Cainey]

I'm most certain it's pawl spring, there is lots of info out there on that.

Transmission can be out in an hour with the right tools, The regular socket will have to be cut down on the outside to fit. Any machinist with a lathe can do that. You will need to have a special flange holding tool to get the output flange off, 162 pounds of torque on that nut.

There are many videos on the procedure.

You won't have to do any shimming if all you are doing is replacing the pawl spring.

I had over 300,000 miles on my 1984 clutch, I would measure the thickness, your call.

 

[811]

Thanks for the input. I plan on pulling the transmission myself but have no interest in opening it up. I believe in the Peter principle & I'll have reached my level of incompetence at that point. It will go to someone who knows what they are doing with transmissions. I'm ordering the socket and a couple of other things from Cycleworks. Will I need the flange holding tool if I go this route? Since some say that the transmission should be gone through/rebuilt at around 65k miles, now seems to be the time to have that done and also have the circlip mod done if one isn't installed.

How do I check the clutch disc for wear? Will I have to pull it off and if so, will an alignment tool, etc be needed? If I've gone that far should I consider a new rear main seal, too? I know more special tools would be needed for that. I do have a nephew who is ASE master certified for cars who could be enlisted to help me if I were to go in that deeply.

Should the drive shaft/u-joint be checked at this time? Are there articles/U-Tube videos to assist me? I know about some on spline shaft lubing (Chris Harris, etc), but not ones for actually pulling the transmission, checking the clutch, etc.

This is something I'd like to get done in a timely manner. I do have the R65 to ride and it's more fun to ride in the mountains but not as suitable for the open road. Thanks again for your help.

 

[shandeland]

You can follow the first part of the instructions here to remove your great box. If you want to inspect your clutch plates this will get you through that as well. If the bell housing is not coated with oil then I would leave the rear main seal alone. However if you also find a mess in there these instructions will walk you through that procedure as well.

http://personalpages.tds.net/~nsgreear/bikes/bmw/clutch/Rear_Main_Seal_Nick.pdf

To just remove and replace the gear box the only special tools you need are the turned down socket and a torque wrench. You might need two torque wrenches, one foot pounds and one inch pounds. Lube the male splines lightly before replacing the gear box.

1981+ clutches to do require you to use clutch pressure releasing bolts. Simply remove the clutch bolts using a chris-cross or star pattern slowly releasing the pressure evenly.

You will need new driveshaft bolts and new clutch bolts.

That is all I can think of right now.

Steve

 

[811]

I quickly scanned the article-looks to be very helpful. The parts list is helpful too-I'll be calling my dealer for more parts. Between this and some videos I'm pretty confident now. Do you have a recommendation of a spline lube & a source for it? I know Chevron NLG1, Guard Dog & Molycoat all have been recommended-just don't know where to find them locally-guess Google can be my friend on that. May as well figure on a new driveshaft boot I guess-the drive shaft fluid was a little milky, indicating some moisture getting in there.

Thanks again for the input!

 

[811]

I quickly scanned the article-looks to be very helpful. The parts list is helpful too-I'll be calling my dealer for more parts. Between this and some videos I'm pretty confident now. Do you have a recommendation of a spline lube & a source for it? I know Chevron NLG1, Guard Dog & Molycoat all have been recommended-just don't know where to find them locally-guess Google can be my friend on that. May as well figure on a new driveshaft boot I guess-the drive shaft fluid was a little milky, indicating some moisture getting in there.

Thanks again for the input!

I decided to carry the bike to Nathan at Boxerworks in Watkinsville, Ga-dropped it off yesterday. Figured it is best that he be able to test drive it after the repair. At 78K miles, I'm expecting to need new bearings & such. He's checking the clutch and rear main seal too. Hope to have it back by mid-June.

Thanks to everyone for chiming in!

 

[1074]

Taking it in

Wise choice. Taking it in to Nathan will get you the best service in your area. He's a great mechanic who will treat you right and you'll know exactly what you need.
It is the earlier clutches that require the special tools for clutch disasembly. Your's is one of them.

 

[811]

Wise choice. Taking it in to Nathan will get you the best service in your area. He's a great mechanic who will treat you right and you'll know exactly what you need.
It is the earlier clutches that require the special tools for clutch disasembly. Your's is one of them.

That's good to hear. I enjoyed spending a little time with him and checking out the bikes there. If the clutch and/or rear main seal are issues then now's the time to deal with them. I'll report back in with the results.

Thanks to all.

 

[811]

That's good to hear. I enjoyed spending a little time with him and checking out the bikes there. If the clutch and/or rear main seal are issues then now's the time to deal with them. I'll report back in with the results.

Thanks to all.

Picked it up from Nathan a couple of weeks ago-it was the shifter spring that had failed. After a rebuild, circlip modification, clutch, rear main & oil pump rebuild it is shifting fine & getting better. Have a little over 500 miles on the rebuild after doing the 6 gap in north Georgia after church yesterday. Will drain & refill with synthetic oil soon.

My thanks to Nathan at Boxerworks in Watkinsville, Ga and to all who gave me input.

Now I need a windshield-the original started fluttering at speed & found it is broken at one of the center mount holes. Thinking about the Clearview unit because their reputation of reduced buffeting. I'm 6'1" and get a lot of buffeting around my head with the factory unit, even with a Laminar Lip added (it did help some). Trying to figure out how to access those 5mm nuts at the center without disassembling the bike-not much room there. Any input from anyone experienced with doing windshield replacement would be greatly appreciated.

 

[20774]

Congrats on getting the transmission serviced. That will give you confidence back when riding the bike.

I'd suggest starting another thread on the windshield issues...best to keep separate issues in separate threads. You can cut-n-paste your question on the windshield into a new thread.