My Love/Hate relationship with motorcylces

[Dennis]

Here is a video for what I have to do next with the transmission.   Russel has loaned me the plate that is used for measuring the end play.

https://www.youtube.com/watch?v=MZTfH7RPeU8

In the meantime, I noticed that the my universal joint (tranny output to drive shaft) is not in good condition.  There is a definite binding on both axis, approximately ? way through the travel.

I was surprised to learn that BMW never engineered the universal joint to be removed and replaced (see my previous thread about the "Debaters").   They sell the complete drive shaft only.  Not surprising, the aftermarket has filled in the void.



The old universal joint is peened in place and that has to be cut out.



Once the new universal joint is pushed in, the four discs have to be welded on.



I ordered it today (from Oshmo Custom Motorcycles), and had a great conversation with Osh himself via conference call.  Osh was out of the country, and his assistant Mark was at the shop.  Osh wanted to make sure I was mechanically skilled enough for the install.  I assured him I was.  I dealt with Mark to persuade him I was desperate and even the ?priority international shipping? would not suffice.  Since I have a Purolator account, it is coming that way in circa two business days.  Huge shipping costs on my account ($96) but desperate times call for desperate measures.

I really want to ride this bike to Dawson City.  The back up plan is the Stolen Sportster.

Peace & Grease, Dennis

[Dennis]

Guy Hudson came by last night and helped me dis-assemble the drive shaft in preparation for changing the universal joint.  As of this afternoon, I still don't have the kit from Oshmo.  I'm not too worried because I have other tasks to complete first.

Guy suggested freezing the transmission shafts, and heating the bearings.  After an hour or so of the bearings in the oven and the shafts in the freezer, we were set to go.





I don't have a press so we just set the bearings on the shafts and hammered them on.  Worked like a charm.

I then re-watched the video on measuring the endplay, and took a stab at measuring with my micrometer.  It is not very good, and the measurements were inconsistent, and not at all worthy of averaging.  I went to uncle Goodgle for some more advice and found this thread.

http://advrider.com/index.php?threads/measuring-gearbox-end-play.796697/



Basically, the technique is to squish down the cover of the case with the gasket in, to the proper torque specs.  Measure the squished solder and subtract 0.05mm (2 - 4 thou inches), and that should be my shim size.

If my shims arrived from Shails today (mail arrives after I leave for work), I will do this next step tonight.

Peace & Grease, Dennis

[Dennis]

I discovered on Friday that Shails never sent my shims.  Russell Parker came through with some leftovers.  After multiple assemblies, the tranny was back together at 3:00 in the morning Saturday night.

Sunday I made the executive decision to move to plan B.  I put signal lights and luggage back on the Stolen Sportster.  New tires, and an oil change.

Just too much to do and not enough test time to commit to the BMW for Dawson City.

Peace & Grease, Dennis

[Dennis]

I haven't posted on this thread for awhile.

This past weekend I dug into the abandoned BMW project which had been sitting exactly as I left it before the Dawson City trip.  Summer allows nothing but basic maintenance.

I got the BMW back together last night.  I started it up and ran it through all of the gears (on the centre stand and still attached to my hoist). Everything works but for the return shifter spring when shifting down.  I have to nudge the shifter up with my toe.  DAMN.  Hopefully its just the new shifter shaft seal which is pretty tight on the shifter shaft.  There is no way I am going to re-open the tranny until I have exhausted a thorough break in.

While it was apart, I removed the Pulse Air Injection System ("PAIS").  Like many motorcycle manufacturers in the 1980s, BMW was doing everything it could to reduce unburned hydrocarbons being released into the atmosphere.  The PAIS was an elaborate system that sensed certain vacuum pressure from the carbs which then opened complex air diaphragms in the air box to allow a burst of air into the exhaust output in the head.  The extra air was supposed to help burn up gas entering the exhaust when the throttle was suddenly rolled back.  While this worked, it also caused excessive heating of the head (particularly in the R100 model), and a notable "popping" sound.





All this is now gone.

Whether permitting, I will bring it out tonight. 

Peace & Grease, Dennis

[Dennis]

I finally got some garage time this weekend and dove back into the BMW.

The bike was stuck in neutral, a few blocks from my house (a few months ago).  When removing the tranny, the first alarm bell was a bunch of aluminum shards in the swing arm/shaft drive housing.  This is a photo of the rubber boot.





It quickly became apparent that the output shaft flange had come loose.  The nut was almost backed off all of the way, and the flange was able to flop around. 



Pretty clear where the aluminum shards were coming from.



I cleaned up the driveshaft and swing arm.  I still have not opened up the tranny.

Peace & Grease, Dennis.

[Dennis]

Shop get together Friday at 7:00 at my shop for anyone who wants to help diagnose my BMW tranny.  It?s out of the bike, and opened up, but I have not disassembled the shifting mechanism.

No obvious broken parts.



Peace & grease, Dennis

[Dennis]

Because I have never rebuilt a transmission before, and since Guy has done a few Beemers, and Keith Larrette has done countless Harley transmissions, I wanted feedback from as many minds as possible regarding my BMW R65 shifter problems.

After much fiddling and diddling, the consensus is that the shifter shaft going into the tranny (with seal and bushing) may not have been completely seated.   The result was that when the screw holding shaft to the shifter mechanisms was torqued up, it was slightly displacing the one part of the shifter mechanism increasing resistance. 

It appears to be operating properly now.

It was a learning experience for those who attended, as the shifting mechanism was handled by everyone to garner their two cents worth.



On reassembly, it became apparent that the threads on the output shaft (see previous post about the loose output flange), were damaged as was the nut holding the flange.  Since the loosened off flange was the result of me assembling the tranny with no reference to a manual or even You Tube, I decided to properly refurbish the threads and then assemble the flange following official BMW protocol (and advice from Guy and Keith).  I have to source a tap and die first.

Another thing I learned is that I have got to get one of those magnifying glasses with the built in light.  I had a powerful light mounted right above the transmission, and everyone was still squinting to see details.  Keith bought his electric magnifying glass, and most wondered how we've working on bikes without one.  Cheap at that Dollar Store.

Peace & Grease, Dennis

[Dennis]

I was able to buy the correct sized die at Chieftain, but not the correct tap.  Instead I purchased a hardened bolt and made one.  My thought was the cost of a tap was probably more than a replacement nut if I screwed it up.  It appears to have worked fine.





Rethreading the output shaft will be another challenge.  I greased up the base of the output shaft and then pushed a tight fitting rag over it.  The plan is that between the grease and the rags, I should be able to keep any metal filings from falling into the tranny.





Stopped for now to think through next step.  None of my die holders will hold the hex shaped die, the shaft spins too easily, and the die only goes on a half turn or so by hand before I need to start torqueing.  My concern is to make sure the die is going on straight.  Usually with a couple turns before it binds, I know I've lined it up.  I'll probably use a square or something.  Task for another night.

Peace & Grease, Dennis

[KrisCarr]

Ive found, by working on german cars, That they take a very different approach to mechanical function than most other manufacturers. There are usually hidden tricks and special tools involved. If BMW builds motorcycles like they build cars I do not envy you sir. Good luck. I find that cursing in german usually helps

[KrisCarr]

I use a socket or wrench to turn dies all the time. you have to go slowly and pay very close attention to the levelness of the die.

[Dennis]

Fixing the stripped thread and output shaft was a breeze; I followed all the advice various members gave me.  Keith said the smooth surfaces of the shaft should be lightly scrubbed with valve lapping compound and then everything carefully cleaned.   Guy Hudson said just hold the shaft with channel locks or vice grips while cutting the thread.  Kris said he's used a wrench on a die.  All worked smoothly.

Guy Hudson took time out of his busy Sunday to come by and show me the correct way to attach the output flange. 

When putting the tranny back in the bike I found another feature that BMW engineers could have improved, and modified the tranny case to allow for sliding in a screw a lot easier when installing the tranny.



Put it all back together, fired it up and tested the transmission with the bike on its centre stand.  It shifts and the shift leaver springs back.  It goes vrooom vrooom. 

Finally.



With all old motorcycles, the story never ends if you're actually going to  ride them.   My "love/hate relationship with motorcycles" continues.  Today I love them.   Tomorrow .....


Peace & Grease, Dennis

[Dennis]

... I still love them.

This actually made me laugh, not cry.



Its not coming from the tranny.  Its from the rubber boot connecting the tranny to the drive shaft.

Peace & Grease, Dennis

[stevecrout]

Well if misery loves company I can sit closer and tell you that I have the same issue with my R80. I thought it was excess from teh rear drive finding its way up the shaft and into the boot as my transmission level is OK. Still haven't figured it out but not sure I really care.  I have a couple of Harleys that teach me all about dealing with loss, especially oil.