Jobber transmission bearing eff-up

[gspd]

After 550,000km, I decided it was time to install a higher 5th gear in my bike.
Transmission is working perfectly, but I think it will be a cool mod.
Might even use less gas.
Haven't taken it apart yet, planning on doing it next week.

I figured since I was going to be in there, I'd do a complete refresh and replace all the bearings.
My bike has never had that infamous 5th gear circlip, so I figure I might as well install one now. I have a spare 'grooved' output shaft on standby.

Yesterday I ordered all the parts I thought I would need from Euromotoelectrics (EME) in Colorado.
6 bearings, a few seals, a gasket, a pawl spring and roller, etc.
Got everything in 24 hours! Great service!
HOWEVER....
Turns out the large bearing (#23 12 1 338 795 for the the input end of the ouput shaft) they sent me is wrong.
The one they sent me has a taper on both sides. It should have a taper on one side of the inner race, and the other side should be flat. The flat side is so it butts up squarely on the circlip. I don't think this is common knowledge.
The older bearings supplied by BMW had the taper on both sides but this taper was filled with a small wire clip. (#3 in the Max fiche pic below) Now, the BMW supplied bearings all have a flat side and don't use that thin wire clip. That's why the thin wire clip is NLA; It's no longer necessary since they switched to a flat sided bearing.
Not sure about when this was change was implemented.

This fuckup is one of the main reasons I have always (until recently) been adamant about using only OE BMW parts. I emailed EME about this and trust they will promptly remedy the situation and supply me with the correct bearing. pics of both bearings below. (They should remove those 'wrong' bearings from their inventory)

I discussed all this in depth with Ted Porter (beemershop) today and he totally concurs.

[melville]

6403? Is the shaft just 17mm where it runs through the bearing?

That's bicycle crank spindle size. That's an impressive piece of metal to take your abuse for 550K KMs.

[gspd]

6403? Is the shaft just 17mm where it runs through the bearing?

The I.D of the bearing is 16.8xxx mm.

Update: EME does sell that NLA wire clip. https://www.euromotoelectrics.com/produ ... ing006.htm
but the correct way to do it is with the circlip up against the flat bearing and no wire clip.
BMW eliminated that wire clip and went to a flat bearing for a reason.

edit -
EME says it's for 1969 to 1987 model years
I guess the flat bearing started in 1988?
2nd edit -
I looked through the Max fiche and it looks that wire clip is NOT NLA.
It just wasn't used on later models.
It is listed for older models.

Maybe Rob F has a service bulletin about this or can figure out the exact date when it was changed.
Either way, the 23 12 1 338 795 replacement bearings from BMW all come with a flat side now (according to Ted Porter) so the wire clip is not used anymore if you buy OE BMW bearings and install them in any year bike.

[gspd]

Just got off the phone with Norm at EME.
He does not have and cannot get the correct bearing.
He is refunding the price of the bearing.
He says they've sold hundreds of these, no complaints.
That doesn't mean it's right.
Although this 'wrong' bearing will work if I add the wire clip, I prefer using the correct flat sided one and no wire clip. My local BMW guy says it'll take 3 weeks to get it from Germany so I will order it from Ted Porter later today.

[gspd]

So...
I've got all (6) correct new transmission bearings, seals, gaskets, springs, and my new higher 5th gear, etc. I also have a almost new spare 'grooved' output shaft staring me in the face so I will, after 32 years and 560,000km, finally have that infamous 5th gear circlip that everybody says I absolutely need. Woohoo!!

I'm just sitting here looking at all those parts looking for a place to nestle.
I have all the tools and all the know-how.
I could almost do it blindfolded.
Now, all I need is some actual motivation to do the job.

My trans is working absolutely perfectly right now, not a hint of swarf on the drain plug when I last changed the oil a few months ago. Shifts like butter. No funny noises. If something was actually wrong with it I'd fix it today. Otherwise, I couldn't sleep.

I just finished replacing the timing chain and head gasket on my wife's 100,000km (actually 98,975km) klx250 (now 300cc). It was running fine but it started burning a bit of coolant recently and the timing chain was becoming rattlingly audible. It runs and sounds like new now.

After many decades of wrenching, I'm realizing that I hate working on bikes (and cars).
I just don't trust anybody to do it for me and I don't want to actually pay someone else to do it.
Anyway, they'll probably surely not do it exactly the way I want it done.

Should I wait until the riding season is over, which is the end of October here?
Or should I tear it apart and smash it back together on the next rainy day?
decisions, decisions....

I'm going for a ride now.

[Steve in Golden]

I think you should wait til the end of riding season. If it ain't broke, don't fix it.

...
My trans is working absolutely perfectly right now, not a hint of swarf on the drain plug when I last changed the oil a few months ago. Shifts like butter. No funny noises. If something was actually wrong with it I'd fix it today. Otherwise, I couldn't sleep.
...
Should I wait until the riding season is over, which is the end of October here?
Or should I tear it apart and smash it back together on the next rainy day?
decisions, decisions....

I'm going for a ride now.

[gspd]

The weather report, rain, rain, rain...
That motivated me.

[gspd]

Finally have that infamous circlip!!! (and a higher 5th gear! and ALL new bearings)
I'm surprised after all the talk about that circlip that my tranny lasted 32 years and 560,000km without it.
In all fairness, I had replaced my front bearing on the output shaft twice during this time span. Never a failure, but twice when I opened the tranny for a routine (preventive maintenance) pawl spring replacement I noticed that that particular bearing was not spinning as smooth as new so I replaced it. Maybe now it will last as long as all the other bearings did.
I made mental notes of my speed vs. rpm in top gear at different speeds with the stock 5th gear, I'll report on my findings after a good ride. Hope it makes a noticeable difference.

[gspd]

Just got back from a test run.
New higher 5th gear.

WOW!

Road speed is exactly 6% higher than previously at any given RPM.
As advertised, as expected...

I'm sure my gas mileage will improve a bit at normal legal cruising speeds

The great thing though is that I can still pull past redline in top gear, which I wasn't sure about before doing this conversion.
That's a whopping 10-12 km/h top speed increase!!
I'm flabbergasted!

Now I just hope that it lasts as long as the stock 5th gear.
Time will tell.
If the gear oil and magnet comes out as clean as usual in 10,000km, I'll highly recommend this conversion to anyone with a GS.

[melville]

What's your final drive ratio?