BMW K bikes (Bricks)


You are not connected. Please login or register

View previous topic View next topic Go down  Message [Page 1 of 1]


Chris350

Chris350
active member
active member
Hi All,

Took out the driveshaft yesterday and I have what appears to be great splines both sides. It was well lubed.

However.....

I have slight notchiness directly in the middle of the swing in both axis'.

Is any notchiness a deal breaker and a call for replacement?

Does this picture indicate anything?

Thanks.

Driveshaft U joint notchiness - how much is too much? '85 20230911

    

Dai

Dai
Life time member
Life time member
If it was one of my Moto Guzzis, I'd be throwing it away, so I'm also waiting for a reply to this one. My guess is that the bike did a lot of straight line work.


__________________________________________________
1983 K100 naked upgraded to K100LT spec after spending time as an RS and an RT
1987 K100RT
Others...
1978 Moto Guzzi 850-T3, 1979 Moto Guzzi 850-T3 California,1993 Moto Guzzi 1100ie California
2020 Royal Enfield Bullet 500
    

charlie99

charlie99
VIP
VIP
best to replace the ujoint ...can be hard to find if its the smaller version , but they do exist 

the notchyness is a sign that the rollers inside have flat sided ...ie worn on one location because the grease has dried out and the rollers just arent rotationg anymore...and then left without use for a long period .

likely outcome if left as is in service , is that the ujoint will bust out  damaging the retaining housing ...making it useless .

a stich in time could save hundreds and availability is becoming less every year


__________________________________________________
cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
1987 k100rs ########   "Red"  - (red sports rs TWB style )
1989 K100rt #009637   "Black Betty"  (naked rt ala Nigel , now sporting an rs main fairing )
    

Chris350

Chris350
active member
active member
charlie99 wrote:best to replace the ujoint ...can be hard to find if its the smaller version , but they do exist 

the notchyness is a sign that the rollers inside have flat sided ...ie worn on one location because the grease has dried out and the rollers just arent rotationg anymore...and then left without use for a long period .

likely outcome if left as is in service , is that the ujoint will bust out  damaging the retaining housing ...making it useless .

a stich in time could save hundreds and availability is becoming less every year
Thanks for the reply Charlie. I was afraid of that. This particular bike was definitely left without use for a long period of time. Looking at the various discussions about replacing this "non-replaceable" u joint sounds not fun. Unfortunate to have such great looking splines and a bad u joint. I'll need to do a think on this one as this is beyond DIY for myself.

On that note... does anyone know of anyone that can replace these u joints in Calgary or Alberta or Canada? I'll start researching and if I find anyone I'll report back. I bet that buying used will be cheaper so I may also look at that option. It's only money right???

    

Point-Seven-five

Point-Seven-five
Life time member
Life time member
I recall looking into replacing the u-joint for one of my past bikes.  While I didn't actually do the replacement, it didn't seem too difficult. 

The u-joint itself is fairly easy to source.  As I recall, the drive shaft uses the smallest common joint size, and the cost wasn't really all that bad, something like $20-25.  The tricky part is that this small joint isn't normally carried by the automotive places that service drive shafts so it can be a little hard to find.  I think the best place to find them is online and from sources that supply agricultural equipment(think tractor PTO drives) or some industrial supply shops.

The last caution is the HP rating of the joint.  There are several different ratings and obviously the BMW shaft needs the highest rating.

As far as getting the joint installed, again, there are places that do agricultural equipment repairs.  It may be possible to have a drive shaft or industrial shop do the job as well.  The old joint is staked in place and requires grinding out the stakes, remove the joint and stake the new one back in place.  I doubt it takes more than one hour of shop time to do the job.


__________________________________________________
Present: 1991 K100RS "Moby Brick Too"
 
Past:
1994 K75RT "Ilsa, She Wolf of the SS"
1988 K100RS SE "Special Ed"
1994 K75S "Cheetos"
1992 K100RS "Moby Brick" R.I.P.
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

RS Rider

RS Rider
Gold member
Gold member
The first place I would try in Calgary is Pats Driveline on Blackfoot Trail.

https://patsdriveline.com/

    

Dai

Dai
Life time member
Life time member
As a final (?) addendum to this thread: I did have a Guzzi UJ explode on me shortly before entering a fast right hander. That was... 'interesting'. The swingarm is still in use, albeit with a huge flat on one side of the housing where the UJ tried - and thankfully failed - to exit. Mind you, the Guzzi swingarm is made from 3mm steel, so that gives you a rough idea of the violence involved. Taking that damage as a baseline and with the K swingarm being a cast housing, it is highly likely that a UJ breaking up on a K would do a good job of destroying the swingarm too. The following consequences don't really want thinking about.


__________________________________________________
1983 K100 naked upgraded to K100LT spec after spending time as an RS and an RT
1987 K100RT
Others...
1978 Moto Guzzi 850-T3, 1979 Moto Guzzi 850-T3 California,1993 Moto Guzzi 1100ie California
2020 Royal Enfield Bullet 500
    

RS Rider

RS Rider
Gold member
Gold member
Did you have any luck finding a replacement u-joint?

    

Point-Seven-five

Point-Seven-five
Life time member
Life time member
Here's a list of standard size part numbers and instructions on how to measure.  Prices aren't all that bad.

https://www.moog-suspension-parts.com/universal-joints-ujoints.asp


__________________________________________________
Present: 1991 K100RS "Moby Brick Too"
 
Past:
1994 K75RT "Ilsa, She Wolf of the SS"
1988 K100RS SE "Special Ed"
1994 K75S "Cheetos"
1992 K100RS "Moby Brick" R.I.P.
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

RS Rider

RS Rider
Gold member
Gold member
Point-Seven-five wrote:Here's a list of standard size part numbers and instructions on how to measure.  Prices aren't all that bad.

https://www.moog-suspension-parts.com/universal-joints-ujoints.asp

Good info, there. Thank you. I wonder who the OEM was for BMW at the time? It looks like Super Strength might be the way to go due to rotational speed of the shaft?

    

92KK 84WW Olaf

avatar
Life time member
Life time member
There have been photos of these joints disintegrating. All the photos I saw there was a resultant perforation of the swing arm. Being a cast single side swing arm means its may well come apart. So if in doubt.....replace it.


__________________________________________________
1992 K100LT 0193214 Bertha Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red 578 bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 689 58,645 now 106,950 miles Deceased.
1983 K100RS 0011157 Fricka 606 Alaska Blue 29,495 miles Damn K Pox Its a Bat outta Hell Now 58,200 miles. 
1996 K1100LT 0233004 Lohengrin Mystic Red 38,000 miles currently 51,800 miles.
1983 K100RS 0004449 Odette R100 colours 58,000 miles. Sprint fairing now 63,390 miles

Past:
1968 Yamaha 80 YG1
1971 Yamaha 125 YAS-1
1968 Honda 125 SS
1970 Honda CD 175
1973 Honda CB500-4
Honda CX 500
    

Point-Seven-five

Point-Seven-five
Life time member
Life time member
If I was to replace the u-joint, I would find a shop that could machine the grooves for the retaining clips if the price was not exorbitant.   That would allow me to remove and service/replace the joint myself in the future.


__________________________________________________
Present: 1991 K100RS "Moby Brick Too"
 
Past:
1994 K75RT "Ilsa, She Wolf of the SS"
1988 K100RS SE "Special Ed"
1994 K75S "Cheetos"
1992 K100RS "Moby Brick" R.I.P.
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

Tranberg

Tranberg
active member
active member
Instead of well meaning links to catalogues with 100s of items, please link to the exact dimensions of the k100/75 joint. There also seems to be great confusion and mix up of Monolever/Paralever and R/K models.. The Australian Hardy Spicer number leads nowhere, no price or dimensions listed. Most search results just lead to fruitless discussion threads like this one here.

    

Point-Seven-five

Point-Seven-five
Life time member
Life time member
Tranberg, I understand your frustration at not having the all answers laid out here for you, but if you go back to my post of October 16, you will see that the link I posted included instructions for measuring your joint so you could determine the correct Moog part number for your bike.  

I suppose I could take my final drive off the bike and take measurements, but unfortunately I have a Paralever and it appears the original poster has a Monolever.  Also, I am pretty busy right now so it might take a few weeks for me to get around to it.

Another thing, most u-joint manufacturers have their own part numbering systems and I personally just don't have the time to research every manufacturer's catalog to post a comprehensive list of the part numbers our bikes use. 

At the end of the day, since you will probably have a specialist replace your joint, the easiest thing would be to just take the shaft to them and let them figure out the part number from their inventory.


__________________________________________________
Present: 1991 K100RS "Moby Brick Too"
 
Past:
1994 K75RT "Ilsa, She Wolf of the SS"
1988 K100RS SE "Special Ed"
1994 K75S "Cheetos"
1992 K100RS "Moby Brick" R.I.P.
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

Tranberg

Tranberg
active member
active member
I see no point in taking out my driveshaft to take measurements, when somebody has done it previously - The K's were not hand-made.

With the dimensions at hand, I could search for the joint, get a price and availablity and then decide what would make more sense to do.

I have a couple of machinist friends, who have the tools needed. They might even be able to repair the splines.


    

Tranberg

Tranberg
active member
active member
Searching some more the dimensions er given here: https://www.k100-forum.com/t14437-drive-shaft-universal-joint-replacement-part-number

19x44 or 19x48mm bot rarities

    

Tranberg

Tranberg
active member
active member
Searching some more the dimensions er given here: https://www.k100-forum.com/t14437-drive-shaft-universal-joint-replacement-part-number

19x44 or 19x48mm both rarities

40-80 Euros from Germany



Last edited by Tranberg on Fri Oct 27, 2023 1:48 pm; edited 1 time in total

    

Laitch

Laitch
Life time member
Life time member
Tranberg wrote:Most search results just lead to fruitless discussion threads like this one here.
That could be disappointing if you are a fruitarian. Sad

    

Chris350

Chris350
active member
active member
RS Rider wrote:Did you have any luck finding a replacement u-joint?

No, not yet. Life got busy and besides ordering a few small parts on black friday, I haven't touched the old girl. She's pushed to the side of the garage so I can get my car in there for winter now.

I've been meaning to call Anderwerks and see if I can bring it in for a second opinion. Its been sitting on my workbench since September and occasionally I'll swing it through it's rotation and it doesn't feel completely bad so I'm on the fence about it.

If I make any progress I'll post again.

    

RS Rider

RS Rider
Gold member
Gold member
I spoke to a parts person at Pats Driveline back in October armed with the info in Tranbergs post, but haven't had the time to drop by. They repair/rebuild driveshafts with staked-in u-joints all the time. I have a spare 16Z shaft with great splines to play with if I want to. However, if I have it disassembled and they can't find a replacement, what then?

I was quoted $60 (if I remember correctly) to have the old one removed so that they could measure it properly and then see what is available as a suitable replacement. They said reinstallation would be a matter of tack-welding washers up against the caps to hold the u-joint in place again. I didn't ask for a cost on that.

I should think that tack-welding will introduce weight to the rotating mass of the driveshaft, so I don't know to what degree that will affect its balance, and if it's even enough to be concerned with.  BMW had/have engineering numbers that state how fast the output shaft of the transmission turns and, therefore, the driveshaft. I have no idea what it is, nor would I be capable of calculating it. Clearly, though, centering the new u-joint in the yoke is a must.

Perhaps someone on this forum could comment further regarding the welds adding additional mass and possible balance issues.

    

Sponsored content


    

View previous topic View next topic Back to top  Message [Page 1 of 1]

Permissions in this forum:
You cannot reply to topics in this forum