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1Back to top Go down    Shaft and drive splines on Mon Dec 16, 2013 3:00 pm

TIV

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I don´t know how things are with the new (Yamaha FJR1300) Police bikes in Reykjavik, but old bikes from the Police are infamous for almost nonexistent maintenance and for having being badly neglected. The only times they got looked at, was when something broke. The tools used seem to have been mostly sledgehammers and crowbars. I have seen some pretty horrible examples of “maintenance and repair” on old Police BMW's and HD´s in my time.

When I got my K75RT ex police bike, one of my first jobs was to lubricate the rear drive splines and gearbox output splines. I used Optimol T white paste, for driveshaft, gearbox and bevel drive splines as recommended at the time by Motobins in the UK. I had a look at the Invoice, to be sure that I remembered this correctly and here is the line from the Invoice. Part No.95815 OPTIMOL T WHITE PASTE DRIVESHAFT/G BOX/BEVEL ALL K 100GRAM TUBE.

My bike had only 29.000 kilometers on the clock when I got it, unusually low for a Police bike, but still showing many signs of neglectance. I suspect that the splines have never being lubricated since new, until I did it. I seem to remember that I found the drive splines to be in good condition but the splines at the rear end of the shaft showed some wear. At the time, I decided to use it, at least until the next lubrication.

Now I'm in there again after about seven thousand miles. I took out the drive and the driveshaft this weekend and after inspecting it I have my doubts about using OPTIMOL T WHITE PASTE on the drive splines and I am afraid I will have to fork out 250 Pounds for a new driveshaft! I think (and hope) the drive splines are good, but the rear splines of the drive shaft show what I think is rather heavy wear and there is a substantial play evident when I slide the shaft upon the splines and wiggle it.

Please take a look at the pictures. All comments and opinions are very much appreciated to help me to decide what to do.



























Last edited by TIV on Mon Dec 16, 2013 4:56 pm; edited 1 time in total


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1990 BMW K75RT Ex-Police
1992 Yamaha FJ1200

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2Back to top Go down    Re: Shaft and drive splines on Mon Dec 16, 2013 3:47 pm

ungaas

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I've seen much worse, to me there is still a bit of life there if you don't twist too quickly. I picked up a second hand shaft in good condition for 90 quid from Motorworks.
Do you have contact with any of the FB members, you could try and persuade them to post you some of their Staburags spline lube.

 


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92 K1100RT  6455097
    

3Back to top Go down    Re: Shaft and drive splines on Mon Dec 16, 2013 4:39 pm

TIV

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I have already got me some Staburags. As I said, the rear splines on the shaft look pretty worn, but the drive splines seem to me to be OK. I really would like to have opinions from forum members about the condition of the drive splines. There is only one way to drive the K75: "like you stole it".



Last edited by TIV on Fri Jan 10, 2014 10:00 am; edited 1 time in total (Reason for editing : correct spelling)


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1990 BMW K75RT Ex-Police
1992 Yamaha FJ1200

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4Back to top Go down    Re: Shaft and drive splines on Mon Dec 16, 2013 9:18 pm

RicK G

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If you are going to ride like you stole it then go steal another one for spares.
The splines on the drive are acceptable but not by any means good and the shaft is considerable worse.
Motobins can supply you with a weld on spline replacement part
http://www.motobins.co.uk/bmw-parts.php?model=K%20Series 
I replaced one a while ago and did a rocwall hardness test which was a bit harder than the OEM but not significantly harder and when I set the shaft up in the lathe to remove the spline there was .013" runout and when finished .002" runout so it came up better than OEM.
Any good engineering shop should be able to do it.
As for the drive I would try to get a 2.91 ratio from a K100RT which is a big improvement over the 3.2 ratio of the original K75 and a bonus is better fuel consumption (they are easier to get as well).


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If everything seems under control then you aint goin fast enough:- Mario Andretti
Bikes 1986 K100RT, 1993 K1100 LT, 1994 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 & 1976 SR 500 Yamaha for now
    

5Back to top Go down    Re: Shaft and drive splines on Tue Dec 17, 2013 5:09 am

TIV

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Thanks RicK. I think I´ll go for the weld on replacement shaft from Motobins. They offer a repaired shaft for 95 Pounds if I send them my old one. In the meantime I will go hunting for a drive. Is it OK to use my „acceptable but not by any means good“ drive in the meantime? Will it harm the „new“ shaft?



It would be interesting to know if someone at the forum has changed the drive to 2,91. What are the pros and cons?



Last edited by TIV on Tue Dec 17, 2013 5:25 am; edited 1 time in total (Reason for editing : addition)


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1990 BMW K75RT Ex-Police
1992 Yamaha FJ1200

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6Back to top Go down    Re: Shaft and drive splines on Tue Dec 17, 2013 5:36 am

MikeP

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I'd not use it. 

Splines are like screw/bolt threads, to work they need the correct interface between the mating surfaces. One that's damaged will soon damage the other.

My guess is that the slight wear you found at the last inspection has resulted in the rapid wear that you now see.

No amount of Optimol paste will stop that happening.


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7Back to top Go down    Re: Shaft and drive splines on Tue Dec 17, 2013 5:39 am

RicK G

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I have a 2.91 drive in my wifes K75RT and it is really good. She gets 65mpg so nearly 400km to a tank and it doesn't sound or feel like iy needs another gear.
I would use it if I had no choice but as Mike said it is best not to start that wear pattern over again.
2.91 gears are easy to find all the K100 RT/LT and K1100LT had them.


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If everything seems under control then you aint goin fast enough:- Mario Andretti
Bikes 1986 K100RT, 1993 K1100 LT, 1994 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 & 1976 SR 500 Yamaha for now
    

8Back to top Go down    Re: Shaft and drive splines on Tue Dec 17, 2013 9:22 am

TIV

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I asked my friend in Hamburg, who has been breaking police BMW for many years, if he could help me. 

Here is his answer:
You can easily fit other bevel drives. The police version has the regular 37:11 that means good acceleration and a lower top speed. The Rpm is very high at higher speed. You can use other drive ratios such as 32:10, 32:11 and more. In some cases you might need a 16 teeth driveshaft. We will brake a K100 in January. Shall we get back to you then?


Frank deals on fleebay if you are interested http://www.neumann-werke.de/


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1990 BMW K75RT Ex-Police
1992 Yamaha FJ1200

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9Back to top Go down    Re: Shaft and drive splines on Tue Dec 17, 2013 9:31 am

RicK G

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There is a 33/11 which is in between the K100RT and your K75 drive but I have a feeling that they were 16 spline shaft.
It is good that you have that contact for parts unfortunately for us in Australia the postage is a real killer.
If you do put a 2.91 drive in it pays to give the engine about 4° more advance at base idle, it gives a heap more torque at low revs and helps overcome higher gearing in 1st gear. I found you need to use the clutch a little more at take off but once you get used to it all is good.


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If everything seems under control then you aint goin fast enough:- Mario Andretti
Bikes 1986 K100RT, 1993 K1100 LT, 1994 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 & 1976 SR 500 Yamaha for now
    

10Back to top Go down    Re: Shaft and drive splines on Tue Dec 17, 2013 10:08 am

TIV

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I am a little confused here. Frank talks about 32:10, 33:11, and you RicK talk about 2.91, 3.2 e.t.c. Forgive me, but english isn´t my native language and I sometimes have difficulties understanding technical terms. 

I realize that we are talking about gearing here. Is 32:11 same as 3.2? Is 33:11 higher gearing than 32:10? Can someone please explain this to me.



Last edited by TIV on Tue Dec 17, 2013 10:09 am; edited 1 time in total (Reason for editing : spelling error)


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1990 BMW K75RT Ex-Police
1992 Yamaha FJ1200

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11Back to top Go down    Re: Shaft and drive splines on Tue Dec 17, 2013 2:22 pm

robmack

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They are different ways of expressing the same concept -- the ratio of input rotations to output rotations.  One is expressed as tooth count (32:11) and the other as the division of those teeth (32 / 11 = 2.91).  Anton's page will give you good insight into the various final drive ratios available for K-bikes & R-bikes. The cool feature of that page is the graphing function that can allow you to compare the engine RPMs for a given speed between different ratios.


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12Back to top Go down    Re: Shaft and drive splines on Tue Dec 17, 2013 2:49 pm

TIV

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Thanks Robert, after looking at Antons page this is easily understood.    My drive is stamped 32/10 which then is 3.2. I have been pleased with it so far, so probably no reason to change this.

I have in front of me a perfect example of what happens if the rear splines are not kept lubricated. My bike has only about 43.000 kilometers on the clock and the final drive and drive shaft are ruined. A new set costs a fortune and a used one will cost half a fortune, so I will try to find a used set in good condition. The problem is that it has to be in a very good condition. If wear has started I´ll be worse off and I´ll be in the same steps in another 8.000 miles or so.

When I got the bike with just inside 30.000 km on the clock I found the splines completely dried out and I suspect they have never being lubricated from new. 

At the time, I thought the drive splines were in acceptable condition, but that the splines at the rear end of the shaft showed more wear. I decided to use it as it was, at least until the next lubrication. As Mike says, it has already been over the hill and what I thought to be a slight wear at the last inspection, has probably resulted in the rapid wear that I now have. Once wear has started, there is no turning back.



Last edited by TIV on Wed Dec 18, 2013 6:12 am; edited 1 time in total (Reason for editing : addition)


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1990 BMW K75RT Ex-Police
1992 Yamaha FJ1200

Cheers TIV
    

13Back to top Go down    Re: Shaft and drive splines on Wed Dec 18, 2013 10:55 pm

ReneZ

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TIV, I wouldn't have an issue using your old drive. Yes, there is some wear, but the drive is quite a bit harder than the shaft inner splines. The shark tooth you see inside the shaft is nowhere near what you see on the drive. There will initially be some accelerated wear until both parts meet up over the full contact surface. I'm really surprised that the wear was so fast after greasing; did you find any water in there?


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Greetings from Florida! Having a 'new' K  :cyclops:    Surprised-o: 

Rene


BMW K100 - 1985 (0030029)
BMW K1200GT - 2003 (ZK01223)
    

14Back to top Go down    Re: Shaft and drive splines on Thu Dec 19, 2013 4:49 am

TIV

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Hi ReneZ. No water in there. Unfortunately I didn´t take pictures when I got the bike and overhauled it about 7.000 miles ago. I might have underestimated the wear at the time, but my feeling is that it has increased, especially the shaft splines.


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1990 BMW K75RT Ex-Police
1992 Yamaha FJ1200

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15Back to top Go down    Re: Shaft and drive splines on Sat Jan 11, 2014 9:13 am

TIV

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I've got a used final drive from Motorworks and a used OEM shaft is on it´s way from Canada. It´s in mint condition according to Bruno at Bruno's Machine & Repair. 

I think the splines are in good condition. 





The crown seal is not leaking, but it´s ugly, so I decided to open the F-D in order to clean it and put in a new seal, O-ring and take a look at the interiors.





Everything looks good on the inside, no chipped teeth or anything else that I can see.




No play can be felt in the crown wheel bearing and it spins freely and smoothly.


It seems that he pinion spins smoothly when I turn it by hand and I can't feel any burr or hear any noises from the bearings. 


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1990 BMW K75RT Ex-Police
1992 Yamaha FJ1200

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gabriel


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17Back to top Go down    Re: Shaft and drive splines on Wed Mar 26, 2014 6:42 am

gabriel


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Oooops!
My photo is gone......

How do I post a photo?..I am using an iPad..
Thanks..

Cheers

    

18Back to top Go down    Re: Shaft and drive splines on Thu Mar 27, 2014 7:21 pm

ReneZ

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Looking good TIV!


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Greetings from Florida! Having a 'new' K  :cyclops:    Surprised-o: 

Rene


BMW K100 - 1985 (0030029)
BMW K1200GT - 2003 (ZK01223)
    

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