76 R60/6 5 speed transmission question

Hello,
So I'm going through this /6 I picked up off of CL. It was not running and has sat for about 18 years. Well a lot of hours later I got it running good enough to drive it around the yard and up and down the street. In my opinion it runs and shifts great. The clutch and brakes are a bit grabby but I'm not concerned about those systems just yet..(in time!). I was warming it all up so I could drain all fluids in exchange for new ones. Im sorry , I did not take pictures because I want to be able to ignore the problem, but I indeed had shiny metal flakes (some as large as .5 mm to mayyybe 1mm square on the transmisssion drain plug magnet. )
I read Snobum's site after the fact and turned the rear wheel cold in Neutral and feel an almost imperceptable (is that a word!!?) amount of notchiness. I broke the oil pan gasket so I've got one on order from Hucky's but what that means is the bike is not running right now so I can't test it hot.

So the big question is: I should 100% pull the tranny and send it in now, right? I shouldnt keep on riding it until I'm stranded, right? I have mentally prepared to fork out the cash to send it in so I'm ok with that, just need to know if I must.
Secondly lets just go nuts: If I pull and send away that tranny, what else should I do since I'm in there, the clutch (or inspect it, anyway?) And if I'm in THERE!, what else should I replace! I have a long Minnesota winter coming up, a heated shop, and a willingness to try anything on this bike.

I have not completed a leak down test yet so I can not say anything about the condition of the top end, but I'd like to get the frame painted or powder coated over the winter too, so I'm sure I'll be removing the engine too!

Nathan.

any reliable idea how many miles are on the bike?

having the trans rebuilt now will cost less than having it rebuilt later... you know this.

I'd wager the bike needs top-end work.

ok, clutch too.

personally I'd wait another year before going all the way with the cosmetics, but our winters here aren't like yours there.

You would wait another season just to evaluate the engine it (if it needs things)? Were you talking about the tranny?
Nate

Sorry, missed the cosmetic word, tried to delete old message

I just worked on my transmission 2 months ago. While I was waiting on parts I did the following:
1. Inspected clutch
2. Replaced rear main seal and oil pump O-ring
3. Replaced breather gaskets since one was shot.

I wouldn't wait on trans work. It won't get better on its own and will cost more to replace things after more wear.

This is good advice. There are no good prospects when metal shows up on the transmission drain plug. It will cost more if put off too long.

The clutch disk needs to be assessed. This is done by measuring the thickness. The figure given by BMW and in all the manuals is conservative and if the disk meets the minimum you can use it because it has substantial wear left in it. Some riders have gone beyond the minimum to squeeze a little more life out of the things but it is debatable if this is of any advantage. So while the trans is away being fixed you will remove and measure the clutch. If this needs work we will talk again but until it is removed you can't know what is needed.

There are options if you need a new clutch. Don't buy the parts till you tell us what the thickness is.

The rear main seal on the engine under the flywheel is usually changed. The old white seals are superseded, they are NLA. The new seal is a Teflon seal, works better and lasts longer. If you find the old white seal has not leaked yet and think you are going to get away with keeping it in place because it is not leaking do not make this mistake. This machine, that has been parked for 18 years, is going to leak. Probably from every seal and joint it has eventually.

Further advice about rebuilding the Airhead transmission; Tell us where you are and we will try to come up with a known Airhead transmission rebuilder. It may still be necessary that you have to mail it but there are a limited number of people we recommend for this job. You may have somebody nearby that rebuilds Harley's or Honda's and he has a good reputation? Don't go there, please, for your own benefit.

We are going to find out about the rest of the machine after the trans is taken care of. At that point the entire rear end will be familiar and clean and greased. You are going to take the rear wheel off, the final drive off and the swing arm off. The battery and battery box will be removed. There are parts of the bike on the rear end to be looked at and cleaned and greased. The swing arm bearings may need attention or the final drive may need attention. But you will have plenty to do I think while waiting for the trans to be finished.

I had assumed my only option was to mail it out, and I contacted Bobs Bmw. I tried to email "Oak" and Moon Motorsports, a bmw dealer in mn. Ok I will remove tranny this week, or even tonight if I can figure it out. I've read the procedures a few times. Seems very straight forward.

Good. Bob's is one of the dealers that are Airhead friendly. He has mechanics on hand that do Airhead maintenance. Have you asked them about turn around time? There is sometimes a wait for Airhead service but that may not involve transmissions. Just ask about turn around time any way. What ever they tell you you can feel confident that they are not leading you on.

The wheel and the final drive come off fairly easy. The splines that mate the two are something to examine and clean when you put them back together. These splines are 50/50 deals. The bumps are the same size as the valleys. As they wear the bumps get smaller. If the bumps are pointy or near pointy they may need more work. I'll post pictures later and we'll examine stuff closer when you put it back together.

But I'm getting too far ahead really. Put the bike on the center stand. Sometimes a pair of 2x4s under the legs of the center stand or a piece of plywood might be needed to get the rear wheel high enough to get it out of the restricted space. Some Airheads are fitted with a fatter tire that can be a problem. Most of the time you'll be able to figure it out. Let us know if you get hung up on any part. There are a few places that you might get hung up but somebody here will know what to do.

Drain the oils from the final drive, the swing arm and the transmission. Since they are not warm they will be slow to drain. That's OK

The shock on the right side can be disconnected and the final drive removed.

Now we are facing the swingarm which it is best to remove. Have you removed the battery and the battery box yet? They are also in the way. You may have a short 10mm boxend wrench in the tool kit that is perfect most times for removing the 4 bolts holding the drive shaft on the transmission flange. If you don't have this particular wrench you'll have to find a 10mm 12 point wrench or a socket that you can get in there. Remove the hose clamps holding the boot on the rear of the trans and by pulling the boot back you can see the 4 bolts. !0mm 12 point.

Once the four bolts holding the drive shaft and trans together are off it's time to remove the pins holding the swing arm onto the frame of the bike. You sometimes need a turned down 27mm socket to fit the locknuts of the swing arm pins. You most likely might get the lock nuts free with the tool kit wrench.



Second tool from the right is a part of the original tool kit for a /6 bike. It has a 36mm box end for the fork center nut, and a few other places. And the 27mm socket that fits the swing arm lock nuts (and also the ignition switch nut on the headlight shell). If you have this tool you may be able to use it to get the lock nuts free. They are often very tight BTW. If the socket end of this wrench is breaking away or otherwise damaged it probably won't work. Some insist you must have the turned down socket but I have usually gotten this apart with this wrench and hitting it with a medium size hammer to create an impact effect.

If the lock nuts are really tight you might get a 27mm socket still tonight. Some have reported that Sears sells a particular one that has thin enough walls to fit. BTW, a 12 point socket works best for this. If one with thin enough walls can't be found you may have a grinder in your garage and can grind down the outside of a 12 point socket to make it fit?

Once the lock nuts are free the pins can be removed and if you noticed earlier that the left shock would have to be removed and it already is then you can pull it and set it aside.

After everything it out of the way and it looks like the transmission is clear to come out you should probably take the clutch throw out pieces off the rear of the trans. and the push rod parts out of the rear cover. The throw out lever on the rear of the trans is held on by an E clip usually. You will have trouble seeing it. Spray with something to clear away the dirt and grime often helps find the clip.

BTW, my writing of this whole procedure may have logic faults in it. Look at what you are doing and you should see what has to happen. Of course you should understand stuff like take the clutch cable off or disconnect the battery. If you get my meaning, you are in charge and we can't watch what you are doing over the internet.

Charlie

PS, the fender and the rear sub frame do not have to come off. In fact there's people that do this with out taking the swing arm off but I am of the school that the job is easier with the swing arm off.

Damnit! When I came back from the garage I see your awesome post. THat was very kind of you. I got it out with zero issues in 2 hours. I was very happy. I was going to remove the clutch stuff right after that but I didnt have the 2" 8mm bolts they say to slowly take the spring tension off with. I was damned tempted to just unscrew everything but clymers warned of personal injury so I will go buy them tomorrow.

I removed the foot shifter and neutral switch, as well as that throw out bearing lever?? (plus the shaft that had the little thing of felt on it. Do I just mail it to them now (UPS) The fluid is drained FYI, which was sad because it is brand new with zero miles on it. I saved the fluid anyway.

There may be some danger from not using the longer bolts for releasing the clutch plates but I always thought the real purpose was to not warp the pressure plate. You can use 8mm bolts from the hardware store and nuts from the same.. I think this info is in Clymer's. Take one bolt out of the flywheel and take it with you to the hardware store tomorrow.

You may want to mark the position of the parts now so that they can be assembled in the same place. A grease type marker works but you should be able to find something. BTW, the flywheel should be in at TDC for these operations. That is traditional but sometimes is more critical later when replacing the flywheel. The mark on a /6 bike is OT. Place flywheel so the OT mark is in the timing window.

I don't think Clymer's mentions blocking the crank. I am going to capitalize this. Block The Crank. Eventualy the flywheel will be off and once that happens there is a danger the crankshft may be inadvertently moved forward. The crankshaft is held against the thrust washers at the back of the engine by the flywheel. What needs to be done is prevent the crank from moving forward during the time the flywheel is off.

Do this BEFORE removing the flywheel bolts. Block The Crank. Take the front cover off the front of the engine. Notice that the forward end of the engine is the alternator. If something is placed on the front of the alternator and then the cover reinstalled this will prevent movement. It has been done with a piece of wood or a T shirt. It's hard to make the block of wood stay put will the cover is replaced but you may construct something. A T shirt works if it is wadded up enough that it is stiff once the cover is replaced. Whatever is used the cover should compress it enough that the crankshaft can't move forward.

I'm posting this now. Hopefully you read this before taking the flywheel off. Please acknowledge that the crank is blocked.

I used the rubber pad from an emergency brake of a 1940's Dodge pick up truck. Saw one once that a guy built a bunch of u clamps and threaded rods into a restraint. Was quit unique and the crank would not move. But the simplest is probably a nylon or plastic bolt with a thread that fits the end of the rotor. The bolt (it's a special bolt but it comes out and can be reused) is removed from the rotor and replaced with the long nylon bolt that is left sticking out enough to hit the front engine cover when it is replaced.

You may want to start cleaning the stuff you took off. Did you remove the wheel and the final drive and the swing arm? The mating splines of the wheel and final drive get cleaned. They may have very little grease on them but you are going to use something, grease, when putting it all together so it lasts longer and works better. We want you to use a special pressure lubricating grease for this. The one that is recommended is Honda Moly 60. You probably have time to find it while the trans is away. I got mine at a Honda dealer, they had to order it but they had it in a couple of days and a $10 tube will last a lifetime. You can find it on the Net too.

There is also a spline input to the final drive that mates with the drive shaft. This is lubed by the gear oil in the drive shaft and is seldom worn.

Did the 4 bolts that held the drive shaft on the rear flange of the transmission have washer on them? Those will be the longer bolts if they had washers. Were any of the washers cracked or any of the bolts loose? As you may understand this particular junction is very important. Use the short bolts with no washers. I will get you the part number later.

You are going to be making a pretty big order of stuff for this job.

The two thrust pieces and the small needle bearing that came out of the rear of the trans, are the thrust pieces in good shape? They may show a little discoloration, like stains, but if pitted they should be changed. The bearing should be examined under a magnifying glass and replaced if any pitting or other signs of stress. I have changed the needle bearing just because I didn't know how old it was. This particular bearing can blow and take the rear cover of the rebuilt transmission with it. Clean all of these parts and look at them with a critical eye.

If you have the swing arm off the bearings can be taken out and the seals removed. It is possible to get the seals out with out ruining them usually.

How about the rubber boot? And the two large hose clamps? My current rubber boot is almost ten years old but I had to replace one hose clamp last year.

Well I'll leave you alone for awhile. others sometimes want to criticize something I said and I should shut up so they can talk.

I think Clymer's gives you a drawing and the deminsions of the tool for holding the flywheel so the flywheel bolts can be removed. You will need this tool. Make one. Or if you want the easy way out and just buy one look up Cycle Works. They have many tools that are useful for Airhead work.

http://cycleworks.net/

A little tricky to navigate but you'll figure it out.

It is possible to remove the clutch without those special bolts but you can get those special bolts and nuts from a GOOD hardware store. Remove one bolt and take it to your local ACE hardware or Sentry hardware store, they will likely have them. Get them a couple of inches long and make sure you get nuts too. If you don't want to remove just one, the thread is fine thread metric 8mm x 1.0mm.

I have shipped the transmission #26347 to Anton Largiader's shop; Virginia Motorrad. He said he is a little backlogged and to expect it back around the first half of October. We usually don't get snow until mid November or early December so maybe this thing will run down the road this year just yet. I will keep this thread updated if anything just as a way to track it for my own records. One of these days Ill figure out how to post the pictures I'm taking.
Disston: Yes all 4 bolts on the drive shaft had washers, and all 4 were cracked. In fact one of them was broken into 2 bits and fell on the ground when I pulled the bolt off. So yes, please provide the correct part number for their replacements that woudl be very kind. I will take good "macro" pictures of the splines. Are you saying inspect the ones at the wheel/final drive connection? Could you be more specific on which splines I should inspect. Also thank you for the information on throw out bearing. I cant really picture what it does yet, but that little bearing sounds important!


Pokie: I have just returend from my local hardware store with 3 bolts that will work, you were indeed correct on pitch. Problem is they didnt have 2" long ones, only 1.75" long, and I am assuming this should work fine, I'll just have to use slightly smaller "spacers" Clymer shows sockets for *** sakes so I'm sure I can come up with something that will work out just right.

Next: (as in right now) off to the garage to remove that clutch assembly! I only get to play around for a few hours and then my wife and I are throwing a leg over the GL and heading even further north for a 3 day camping trip/wedding of our good friends and motorcycling couple we try to ride with each year so it is cool we get to go to their wedding on our ride. I'll be cooking tonight (and actually first thing tomorrow morning too) for 20 folks, I've got my fingers crossed that goes as well as the tranny removal.

Interesting, I have not read the Clymer manual.

Remove three equal spaced clutch bolts and replace them with the bolts, nuts and washers you just bought.

I just thread the nuts to the heads of the long bolts, put a washer between the nuts and the clutch plate, thread in the bolts until they bottom then thread the nuts all the way down until they and the washers are against the clutch plate. Remove the final three clutch bolts then start backing the nuts of the long bolts off a little at a time until the pressure is off. Try to keep the amount of turns the same for each nut to keep the plates even as the pressure is released. While backing the nuts off, make sure the bolts themselves don't start to undo. If there is still pressure on the nuts by the time you get them all the way backed off, start loosening the bolts until everything comes loose.

This is the wheel I currently have on my R90/6. It came off a 1977 R100S. The drum wheels interchange for many years, not sure when they don't except you will run into problem if you try to use a cast wheel in place of a spoke wheel or try to use a /5 for a later wheel or vice versa. In the picture you are looking at the drive spline cup that is riveted to the wheel hub. These splines are in great shape I guess at least 80% good.



This is the wheel I took off my R90/6. It still has pretty good splines. I put this spline cup on this wheel about 12 years ago but the method I and my friend used to attach it was not correct. After 12 years one of the rivets let go. lucky I was only two blocks from home. It made a terrible noise and scrapped the rest of the way to my house but when I took it apart I found the broken rivet wedged against the brake shoe and making all the noise. I removed the broken rivet and continued riding later that week. When the second rivet broke about ten days later I decided to find my spare R100S wheel. I bought a new tire and everything's happy again.



This is a final drive unit as the same vintage as our bikes. Notice the drive splines here are on their last legs. They should look the same as those splines on the wheels. Drive splines on the final drive and the wheels are bumps and valleys. When new the bumps an valleys are the same size, roughly. As they wear the valleys get larger and the bumps get smaller. When the bumps are this pointy they are finished. You might make it home if you found this situation out on the road but it is really something that is supposed to never happen if you are paying attention. There was a rider only a couple years ago got stranded several states from home because he bought an Airhead and tried to cross the country on it because he heard that theses bike can cross the country. Happened on a different list I think. We explained that these bikes will cross the country after you have replaced every part on them.

Now you know. You will clean and lubricate the drive splines of the wheel and the final drive every time there is a new tire installed or the wheel is off for any other reason. I use coffee stirrer wooden sticks to scrape clean, you have to reach inside to get the old grease out, and sometimes I use a little cotton swab action. A little brake cleaner also helps but it is not something that has to be all that clean. Just get the majority of old grease out.

The grease to use here is Honda Moly 60. Not a lot is needed or desired. but you do have to get some in each valley and it is a little finicky to get much of it all the way inside. i like to slide the wheel on, wiggle it back and forth then remove to look at what sort of distribution I have.

If you over grease the splines the excess will be forced out and spun by centrifugal force on the brake hub where it will lubricate the brake pads. Something to avoid.

I'll be back. Charlie

The connection of the drive shaft to the output flange of the transmission used those longer bolts with washers up through 1980. In 1981 BMW came out with the short bolts. Those working on their older than 1981 machines may use the shorter bolts. You can not just use the longer bolts and leave the washers off. They will contact the transmission rear seal and cause trouble. If you used the long bolts your supposed to get new washers, in fact BMW wants you to use new bolts also. So just use the short bolts. If you used the long bolts with washers you will also likely find more broken washers when it gets taken apart some day. At a dealership parts counter some may try to sell you the long bolts and washers. Don't go there. In fact if that happens try not to laugh too much in the guys face. But insist the short bolts are what you want. (most of them know this but you never know, ya know?)

26 11 1242 297 Short Bolts

If the rubber boot is cracked it may need replacing. Judgement call maybe but a pain to replace later if you don't replace a cracked one now.

33 17 1 230 304 Rubber Boot

The long hose clamps are usually good but sometimes one gets a screw messed up or have another problem.

33 17 1230 297 Long Hose Clamp

There's a paper gasket between the swing arm and the final drive. Not expensive. The old one may work but here's the # for a new one.

33 17 2 311 098 Gasket

There are many places there may be some problem nut most things go back together like other machines. Pay attention to screw and stud threads. Damaged threads should be repaired or replaced.

Finally I have to yell a little bit. This happened only one month ago. Another newcomer was doing a rear main seal and several of us told him to BLOCK the CRANK. Well his excuse was that he never paid attention to anything that didn't make sense and since he didn't know what we were talking about he ignored the advice.

Failure to BLOCK THE CRANK may lead to several thousand dollars damage to your bike.

Our friend last month got off easy. But it doesn't always end this way. Failure to block the crank can and does destroy the engine bottom end the the whole thing has to come apart to repair.

Please write that you understand this and have taken care of Blocking the front of the engine crankshaft.

Picture would be nice?

I wrote that up last night on my phone but it didnt post for some reason. Yes I went out today and blocked the crank with a small towel and really jammed it in there super tight and secured the front cover down. THen I went and removed everything but the flywheel. I have all of the non reusable bolts out but I cant pull that flywheel out. That is common, I assume? I tried screwing the long bolts in there and then yanking on them (fairly hard) to the point where my gut said to stop and ask what's going on. I kind of tapped along the edges with my rubber mallet. I could get it to wiggle a bit but not come free. I am following the Clymer steps so I did mark everything as far as making sure it goes back in on TDC matching with where it should on the crank. Can you imagine if you didnt do that? ha! Well I'm almost out of here until Monday if you don't hear back that is why. Thank you for the effort to show me the splines, that is awesome! Oh, I do have every intention of crossing the country on this thing too, when it is ready. That is my ultimate goal with this thing. Not to make it look pretty (well not goal #1 at least) but I have some very long rides on the schedule for this bike. (A 2000 ride mid summer to the Mississippi Delta region, a 1500 mile ride in September 2014 around Lake Superior (This year I'm taking the HD), and I'd love to try a big 6000 mile ride with my buddy in his proven 76 GL1000 to an undisclosed location. But we may have to wait a couple years on that one to get enough time from work built up. I mention that because it may change some of your advice? Maybe not.



Here is the tool I used to hold the flywheel in place. It did not leave any marks after I was done but I've got some steel laying around so I'll actually make a correct tool. Yes I know I was most likely tempting fate and lucky I didnt mess up any of the flywheel threads but nothing bad happened.

I use a really old puller that I've had for years. It is a Plomb 4010 puller. It has the 11.5" yoke, #4011. The number on the yoke is how you spot it. The nice thing about this puller is it is the yoke is long which is what you need to pull the flywheel off.



This picture in not my puller but one just like it. This picture also only shows the hook arms used for pulling and not the bolt arms which is what you need.

Another puller may be found to do the job. Just remember the flywheel is pretty wide and you need a bolt puller like a steering wheel puller but a steering wheel puller is too narrow. Same thing for the vibration dampener puller, too narrow.

Cycle Works makes a puller for this;



They sell this for $26. The Plomb puller I showed earlier goes for $70 to $100 on Ebay but the bolt puller arms are rare.

http://www.cycleworks.net/index.php?main_page=product_info&cPath=29_33_51&products_id=374

Finally I have gotten the flywheel off by rocking it but don't think it is good for the thing. Try to use a puller. You may find a spacer and you may find an O-ring under the flywheel. I don't know what year these changes start.