Author Topic: Clutch Bolts ?  (Read 13412 times)

Offline whosyurdaddy

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Clutch Bolts ?
« on: May 12, 2017, 04:50:48 PM »
   While doing my spline service I thought I would source new clutch bolts other than BMW . A local nut and bolt shop actually had 7mm bolts but with a hex head , I went ahead and bought from BMW but when comparing  the hex head versus socket head I'm really not sure why the hex can't be used . I'm just wondering if anyone has gone the hex head route and did it work  .
  • Central Indiana
  • 1991 K100RS SOLD

Offline Motorhobo

  • +25 years of K75
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Re: Clutch Bolts ?
« Reply #1 on: May 12, 2017, 05:16:19 PM »
I'm not a metallurgist or a fastener engineer but I think the clutch bolts aren't special because of the fastener type but rather because of the head profile and type of metal. The bolts are designed to work with the teeth washers so that the teeth washers grip into the metal. These bolts strip out really easily, which indicates to me that the metal is soft rather than super hard and/or the socket is too shallow to accommodate the amount of torque put on them -- but I think it's the former. I think the soft metal of the bolt and the teeth washers are paired and the low head is used maybe because has a wider profile than a standard socket or hex head.

I would definitely not use any bolt without the teeth washer that goes under it according to the manuals and the fiche, and if the metal of the bolt is too hard for the teeth washer to grip into, it's just going to flatten the teeth washer when you torque it down and that will defeat the whole purpose of the teeth washer.
 
I don't know what will 'work' and what won't - but I'd think you'd want to make sure that whatever bolt you use has the same height as the low head bolt it is replacing. For myself, I'd rather use a used clutch bolt than a new one that wasn't a match with the OEM one.

I was looking here for aftermarket options:

http://www.mrmetric.com/product/metric-socket-screws/metric-low-head-screws?page=2

Have it on my list to do to call them and possible even send them a used clutch bolt to compare but I can't find the big bag of old clutch bolts I had somewhere -- losing shit is the bane of my existence.

Sorry I can't give you a more comprehensive answer. The other place low head bolts are used on the K75 is to keep the footpeg assembly together from the inside of the footpeg mount. If those are the same kind of metal, then maybe it's safe to say that the clutch bolt isn't any softer than any other low head bolt you can find.

THere are a number of clutch bolt threads here -- search for 'clutch bolt' -- maybe you'll turn up more info.
1994/1995 K75 ABS Frankenbike: original engine 136k miles, frame from Gary Weaver (RIP), 173k miles -- Current Odometer: 198k miles
1994 K75 since 2013, 82,000 mi (19k mine) w/California Sidecar Friendship II Sidecar & Black Lab 'Miss B' - RIP

Past: 1974 Honda 550/4 (first bike), 1994 K75 (sold), 1995 K75 ABS (parts bike), Sidecar Dog & Best Bud 'Bo' - RIP

Offline whosyurdaddy

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Re: Clutch Bolts ?
« Reply #2 on: May 12, 2017, 05:24:41 PM »
The original washer are called gripper washer I believe but when you order from BMW now you get shaker washers which I have a drawer full , very common at most hardware stores . The bolts themselves from what I was told are a soft alloy .  I'm finding nothing special about the bolts other than I don't want to tear my bike apart again because I tried to be different
  • Central Indiana
  • 1991 K100RS SOLD

Offline Martin

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Re: Clutch Bolts ?
« Reply #3 on: May 12, 2017, 05:31:19 PM »

If your worried about the bolts loosening you could apply medium strength Loctite as an extra precaution.
Regards Martin.
  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline Motorhobo

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Re: Clutch Bolts ?
« Reply #4 on: May 12, 2017, 09:05:36 PM »
If your worried about the bolts loosening you could apply medium strength Loctite as an extra precaution.
Regards Martin.
Hmmm...have you ever done that with non OEM clutch bolts, Martin? Trying to get poor whosyurdaddy to be the guinea pig, are you?  :yow

The original washer are called gripper washer I believe but when you order from BMW now you get shaker washers which I have a drawer full , very common at most hardware stores . The bolts themselves from what I was told are a soft alloy .  I'm finding nothing special about the bolts other than I don't want to tear my bike apart again because I tried to be different

Actually, according to my research they're called external tooth washers, also serrated lock washers:

https://www.grainger.com/product/GRAINGER-APPROVED-Steel-External-Tooth-WP136278/_/N-1z0o4o3/Ntt-External+Tooth%2C+Closed+Perimeter?sst=subset&s_pp=false&picUrl=//static.grainger.com/rp/s/is/image/Grainger/25DN34_AS01?$smthumb$

http://www.mrmetric.com/M61165

and if BMW is selling your basic Ace Hardware variety for $1.95 a pop, then that is really fuuuuuuud up, because the ones I found at my local Ace weren't even close.

Here's what the OEM part is supposed to look like according to the Max BMW fiche...see attachment.

Truth is, I don't know why they designed it why they did, but I want to stick to the original spec and find the closest aftermarket option there is...but that's just me.

whosyurdaddy, if it were me I'd use whatever used OEM bolts I have and whatever washers BMW gave you and button 'er up. If you don't have a complete set of used OEM clutch bolts at hand, I'd order new OEM ones to complete the set with one or two to spare. I personally wouldn't use any metric bolt that wasn't low head and at least a close match to the OEM. But like I said, I'm not a metallurgist, just some dude with a couple K75s and a wrench who has to believe that the BMW engineers back in 1982 had a reason for the decisions they made. Hopefully by the next time around around someone will have figured out what the aftermarket offering is, because the prices BMW is charging for the ten-cent bolts is...well, let's call it non-consensual anal penetration by a foreign object.
1994/1995 K75 ABS Frankenbike: original engine 136k miles, frame from Gary Weaver (RIP), 173k miles -- Current Odometer: 198k miles
1994 K75 since 2013, 82,000 mi (19k mine) w/California Sidecar Friendship II Sidecar & Black Lab 'Miss B' - RIP

Past: 1974 Honda 550/4 (first bike), 1994 K75 (sold), 1995 K75 ABS (parts bike), Sidecar Dog & Best Bud 'Bo' - RIP

Offline Martin

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Re: Clutch Bolts ?
« Reply #5 on: May 12, 2017, 10:02:12 PM »

Motohobo actually yes, I reused the bolts and washers and a dab of  Loctite. I would rather use the original unless you can get a really close match. But in saying that if a bolt is the same, except that it is a hex instead of an allen and the head has clearance and the washers are correct for the bolt and the application, I can't really see it causing any problems.  :dunno
Regards Martin.
  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline Motorhobo

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Re: Clutch Bolts ?
« Reply #6 on: May 13, 2017, 06:22:15 AM »
Motohobo actually yes, I reused the bolts and washers and a dab of  Loctite. I would rather use the original unless you can get a really close match. But in saying that if a bolt is the same, except that it is a hex instead of an allen and the head has clearance and the washers are correct for the bolt and the application, I can't really see it causing any problems.  :dunno
Regards Martin.

Well -- hats off to you! I don't have to guts to stray too far from 'the book' -- you're an inspiration to us all  :clap:

I assume you're talking about blue Loctite -- the kind that can be removed with hand tools.

There you go, whosurdaddy, if it's good enough for Martin it should be good enough for you.

I'm still going to look for a match for those OEM parts, though. I've stripped enough of those clutch bolts even without Loctite -- would prefer no additional complications in the process. But that's just me :-)
1994/1995 K75 ABS Frankenbike: original engine 136k miles, frame from Gary Weaver (RIP), 173k miles -- Current Odometer: 198k miles
1994 K75 since 2013, 82,000 mi (19k mine) w/California Sidecar Friendship II Sidecar & Black Lab 'Miss B' - RIP

Past: 1974 Honda 550/4 (first bike), 1994 K75 (sold), 1995 K75 ABS (parts bike), Sidecar Dog & Best Bud 'Bo' - RIP

Offline whosyurdaddy

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Re: Clutch Bolts ?
« Reply #7 on: May 13, 2017, 06:41:58 AM »
  I'm not worried about bolts backing out I was just looking for a more cost effective replacement part . I mean $38 and change for 6 bolts and washers . I am using the BMW bolts because the damage that could happen is not worth the risk and someone mentioned the weight difference between the 2 bolts might cause a problem .
  • Central Indiana
  • 1991 K100RS SOLD

Offline Motorhobo

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Re: Clutch Bolts ?
« Reply #8 on: May 13, 2017, 07:06:17 AM »
  I'm not worried about bolts backing out I was just looking for a more cost effective replacement part . I mean $38 and change for 6 bolts and washers . I am using the BMW bolts because the damage that could happen is not worth the risk and someone mentioned the weight difference between the 2 bolts might cause a problem .

That's a really good point -- hadn't thought of that.
1994/1995 K75 ABS Frankenbike: original engine 136k miles, frame from Gary Weaver (RIP), 173k miles -- Current Odometer: 198k miles
1994 K75 since 2013, 82,000 mi (19k mine) w/California Sidecar Friendship II Sidecar & Black Lab 'Miss B' - RIP

Past: 1974 Honda 550/4 (first bike), 1994 K75 (sold), 1995 K75 ABS (parts bike), Sidecar Dog & Best Bud 'Bo' - RIP

Offline Laitch

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Re: Clutch Bolts ?
« Reply #9 on: May 13, 2017, 09:33:38 AM »
I am using the BMW bolts because the damage that could happen is not worth the risk and someone mentioned the weight difference between the 2 bolts might cause a problem .
It's time for you to consider polling the membership, hoosierdaddy. I've rough draft here of poll questions that you can use gratis, based on your apparent rejection of non-oem solutions to this first-world dilemma.

1. Assemble with oem old bolts and oem old washers.
2. Assemble with oem old bolts and oem new washers. 
3. Assemble with oem new bolts and oem old washers.
4. Assemble with oem new bolts and oem new washers.
5. Wait for for that certain, trusty someone to tell you what you should do.

  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline Andy FitzGibbon

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Re: Clutch Bolts ?
« Reply #10 on: May 13, 2017, 09:45:11 AM »
I've stripped enough of those clutch bolts even without Loctite -- would prefer no additional complications in the process. But that's just me :-)


Heat, from a high-wattage soldering iron or a small torch, will help break the bond of blue or red Loctite.  Helps a lot with non-Loctited bolts, too.


Andy
  • Montrose, WV
  • 1985 K100RS, 1972 R75/5, 2012 Suzuki DR650

Offline Motorhobo

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Re: Clutch Bolts ?
« Reply #11 on: May 13, 2017, 10:19:27 AM »

Heat, from a high-wattage soldering iron or a small torch, will help break the bond of blue or red Loctite.  Helps a lot with non-Loctited bolts, too.


Andy


Sure, but it's more an issue of how many hoops do I want to jump through? I want to put a washer down, put a bolt over it and torque it down, repeat 5 times. I don't want to be putting 6X loctite on there when that's not necessary if you have the correct parts. That's not a piece that should require any heat. I've drilled out maybe 2% of those bolts...much less than the time required to apply loctite and remove its residue 6X per cycle. 
1994/1995 K75 ABS Frankenbike: original engine 136k miles, frame from Gary Weaver (RIP), 173k miles -- Current Odometer: 198k miles
1994 K75 since 2013, 82,000 mi (19k mine) w/California Sidecar Friendship II Sidecar & Black Lab 'Miss B' - RIP

Past: 1974 Honda 550/4 (first bike), 1994 K75 (sold), 1995 K75 ABS (parts bike), Sidecar Dog & Best Bud 'Bo' - RIP

Offline Andy FitzGibbon

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Re: Clutch Bolts ?
« Reply #12 on: May 13, 2017, 10:30:51 AM »

Sure, but it's more an issue of how many hoops do I want to jump through? I want to put a washer down, put a bolt over it and torque it down, repeat 5 times. I don't want to be putting 6X loctite on there when that's not necessary if you have the correct parts. That's not a piece that should require any heat. I've drilled out maybe 2% of those bolts...much less than the time required to apply loctite and remove its residue 6X per cycle.


That's fine... I was just putting the technique out there.  It's saved me a lot of time over the years.


Andy



  • Montrose, WV
  • 1985 K100RS, 1972 R75/5, 2012 Suzuki DR650

Offline Motorhobo

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Re: Clutch Bolts ?
« Reply #13 on: May 13, 2017, 01:59:13 PM »
Well -- just got an answer from the Flying Brickers across the sea -- AFAIC this problem is solved.

That's about $16 for the set...can't beat that with a baseball bat.

http://www.jt-c.com/product_info.php?info=p282_schraubensatz-bmw-21211454417---21211242377.html

I am placing an order very soon -- PM me if you want some....save on intl shipping.

V
1994/1995 K75 ABS Frankenbike: original engine 136k miles, frame from Gary Weaver (RIP), 173k miles -- Current Odometer: 198k miles
1994 K75 since 2013, 82,000 mi (19k mine) w/California Sidecar Friendship II Sidecar & Black Lab 'Miss B' - RIP

Past: 1974 Honda 550/4 (first bike), 1994 K75 (sold), 1995 K75 ABS (parts bike), Sidecar Dog & Best Bud 'Bo' - RIP

Offline The Mighty Gryphon

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Re: Clutch Bolts ?
« Reply #14 on: May 13, 2017, 03:51:26 PM »
Wow, what a great site! 

Did you ever want to connect something to the accessory plug in the relay box???  They have the mating connector with 4 ft of wire connected to it for under $20.  Could have used it last week when I started wiring a cruise on my RT.

http://www.jt-c.com/product_info.php?info=p74_the-k-cable.html

They're in my bookmarks.  Thanks for the heads up Motorhobo!
  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

Offline Motorhobo

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Re: Clutch Bolts ?
« Reply #15 on: May 13, 2017, 04:12:49 PM »
Yeah -- this Till guy's store is like a candy shop for motobrickers.


BTW the answer I got to the reusability question was basically -- if you can get it out in one piece, reuse it. He was referring to the bolts though, not the tooth washers. Those flatten out and lose their bite after one use, so I'm going to look for a supplier -- might not be so easy since these are M7 bolts -- not a very common size.
1994/1995 K75 ABS Frankenbike: original engine 136k miles, frame from Gary Weaver (RIP), 173k miles -- Current Odometer: 198k miles
1994 K75 since 2013, 82,000 mi (19k mine) w/California Sidecar Friendship II Sidecar & Black Lab 'Miss B' - RIP

Past: 1974 Honda 550/4 (first bike), 1994 K75 (sold), 1995 K75 ABS (parts bike), Sidecar Dog & Best Bud 'Bo' - RIP

Offline Martin

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Re: Clutch Bolts ?
« Reply #16 on: May 13, 2017, 05:38:31 PM »

Motohobo we have a bigger problem than inmates in the US and the UK. Local availability and the price of OEM parts which can be four times plus your price. Any thing remotely unusual is extremely hard to get, and if you do find it it will at least cost you a leg, if not an arm as well. We have one BMW wrecker in Queensland and he can charge what ever he likes. However I do love a challenge. and it keeps me on my toes finding ways to get around non availability and exorbitant prices.
Regards Martin.

  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline Motorhobo

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Re: Clutch Bolts ?
« Reply #17 on: May 13, 2017, 05:57:00 PM »
Hey Martin -- well, I guess point from this thread...


http://www.motobrick.com/index.php/topic,9681.25.html


Is that BMW OEM per se is dead as a doornail -- which is where BMW is pushing it. The aftermarket BMW suppliers ship to OZ, don't they? Check out the shipping options link on the Till's site:


http://www.jt-c.com/


OZ isn't listed but I think that's an oversight rather than an exclusion -- they ship everywhere else for $15 US. BMW doesn't want your business -- they've been working with people like Till to behind the scenes to offload the supply chain to third party vendors. We're in the same boat as you in that there are no more brick--and-mortar stores to buy things from. We have to order them and wait -- you have to wait longer of course -- but the price is going to be the same worldwide plus shipping.


I think what we motobrickers need to do is to find out what the third party vendors have and organize collective buying orders. There's a whole section on the flyingbrick.de site for collective orders. We need to buy in advance instead of on demand and forget about BMW dealers as suppliers of what we need. Nobody is going to buy an exhaust or heat shield or transmission new -- we're going to get that from scrap. All the rest we get from the third party folks per UPS.




That there's only one breaker in OZ -- that's a bummer -- seems like every OZ motobricker needs at least one parts bike on the premises...
1994/1995 K75 ABS Frankenbike: original engine 136k miles, frame from Gary Weaver (RIP), 173k miles -- Current Odometer: 198k miles
1994 K75 since 2013, 82,000 mi (19k mine) w/California Sidecar Friendship II Sidecar & Black Lab 'Miss B' - RIP

Past: 1974 Honda 550/4 (first bike), 1994 K75 (sold), 1995 K75 ABS (parts bike), Sidecar Dog & Best Bud 'Bo' - RIP

Offline whosyurdaddy

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Re: Clutch Bolts ?
« Reply #18 on: May 13, 2017, 06:43:04 PM »
It's time for you to consider polling the membership, hoosierdaddy. I've rough draft here of poll questions that you can use gratis, based on your apparent rejection of non-oem solutions to this first-world dilemma.

1. Assemble with oem old bolts and oem old washers.
2. Assemble with oem old bolts and oem new washers. 
3. Assemble with oem new bolts and oem old washers.
4. Assemble with oem new bolts and oem new washers.
5. Wait for for that certain, trusty someone to tell you what you should do.


  Thats a good start although number 3 is irrelevant since the original oem washers are not removable . I have a revised version I think is closer to what this post is about .


1. Who is OK with spending nearly $40 for 6 bolts and washers
2. Who is NOT OK with spending nearly $40 for 6 bolts and washers
  • Central Indiana
  • 1991 K100RS SOLD

Offline Martin

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Re: Clutch Bolts ?
« Reply #19 on: May 13, 2017, 06:49:30 PM »

One wrecker in Queensland he is local but knows how to charge a captive audience, two engine mounting bolts crash bar type $20.00 exhaust mica gasket $50.00 speedo housing just the shell $100.00. I don't know entirely what the other states have as far as BMW wreckers some probably better some worse. For the last couple of years I have been trying to slowly buy parts that will disappear or that take too much time to get overseas. I also trying to find old specialist tradesman who are now disappearing I have found a good source of brake hoses  a master cylinder sleeve guy. And I might have found a guy the does splines, I am still trying for more information. I now have a lot of bits now in stock, but I do  need a few more  expensive things like a gearbox and drive shaft.  I do have a mate with three K75's and a K100 and another pile of K75 bits two engines boxes and shafts. I was trying to help him get them back on the road but have given up. He won't sell anything to anybody but he has given me a couple of things and I can borrow bits while I am chasing parts. I have made a lot of special tools required for the brick and I have a pretty good workshop. I love the challenge of keeping my brick going without having to sacrifice an arm or a leg.  :hehehe I would however love access to your Harbour Freight and some of your other suppliers, some of which won't ship to OZ.
Regards a vented Martin. :riding:
  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline The Mighty Gryphon

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Re: Clutch Bolts ?
« Reply #20 on: May 13, 2017, 07:05:51 PM »
Martin, are you a member at the K100 forum?

http://www.k100-forum.com/portal

There is a very large, organized and active contingent of Ozzies there.  They swap parts, work on each other's bikes, and seem to always have a ride organized to go somewhere.
  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

Offline Martin

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Re: Clutch Bolts ?
« Reply #21 on: May 13, 2017, 07:53:03 PM »

I used to be, I tried to get back on but I had trouble with Email addresses matching with user name. User name used, Email address used, could not work out what matched what. I actually tried to find Motobrickers locally with one post but alas forsooth it was in vane. I am resigned to Bricking alone. :dunno However I might try again now that I have a new Email provider.  :hehehe
Regards Martin.
 

  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline Laitch

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Re: Clutch Bolts ?
« Reply #22 on: May 13, 2017, 08:04:52 PM »
1. Who is OK with spending nearly $40 for 6 bolts and washers
2. Who is NOT OK with spending nearly $40 for 6 bolts and washers
Doesn't bother me. I like supporting local business and I like M&Ms.  :hehehe
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline Laitch

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Re: Clutch Bolts ?
« Reply #23 on: May 13, 2017, 08:09:19 PM »
Doesn't bother me. I like supporting local business and I like M&Ms.  :hehehe
Of course, I reused mine after I measured the friction disc last time I did a spline lube and I've ridden 22K miles since then, so my vote will skew your data. :giggles
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline Laitch

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Re: Clutch Bolts ?
« Reply #24 on: May 13, 2017, 08:19:06 PM »
Thats a good start although number 3 is irrelevant since the original oem washers are not removable .
Why do you suppose they are listed separately in the parts fiche? Am I involved with the wrong bolts and washers here? Help me catch up.

* Washer and screw from MAX BMW parts fiche.png (17.29 kB . 163x258 - viewed 451 times)
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

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