The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: montmil on May 23, 2009, 07:11:10 PM
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Didn't want to hijack the LS Rim Rehab thread so here's a non-rim question that sorta sneaked in there...
Bengt mentioned he was about to replace the driveshaft boot on his scooter. The question came up about reusing the 12-point bolts. Mike stated that a Ft Worth BMW dealer said something to the order of, "If you find lock washers under the bolts, replace the bolts."
I checked the A&S fiche and the diagram showed wavy washers under the flange attach bolts. Technically, I do not view the wavy washer to be anywhere close to a split-ring washer. The question is - among those that have replaced the rubber boot - what has been found, if anything, under the bolt head? Wavy, split or nada.
The second question... if the wavy washers should be used even if there were no washers found upon disassembly?
Thirdly... are split-ring style washers even used at all in the flange assembly?
Monte
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The washers were used at one time, but I don't think the factory used them after 1978.
But it's hard to say that somewhere along the way, that they may have been installed by some unknowledgeable individual.
The problem with the washers, and I don't know if they were the split lock washers, or just 'wave' washers that BMW is fond of using, was that they would break, fall out, and then the bolt was loose .
I have the original bolts and have reused them numerous times, and have not have a problem .
They are a pain to properly torque, I have a Snap-On tool called a torque adapter, looks like a 12 point box end wrench about 2 inches long, with a 3/8th's inch drive square hole at the other end .
Use a torque wrench and tighten to the specified torque, and 28 years later, no problems.
The Snap-On part number is : FRDHM10.
I got mine in 1984, and I paid about $10 for it, I havn't checked lately, but I think t is in the $25-30 range today.
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The washers were still used in 1980, they were on the R65RS. It's possible the switch was made when the clutch, flywheel, and everything else changed. Everything I've read indicates that these old bolts need to be replaced with the shorter bolts that don't use washers. I also think going "by the book" forces you to use new bolts every time. I guess this would be a 100% safe thing to do but I just re-use the old (unless they had washers) ones and use blue Loctite... I just crank 'em down as hard as I can with a longish Snap-On box end wrench.
Just checked the ETK and it shows a change date on the bolt of 9/80 but, oddly enough, shows the washer for all years which I believe is incorrect.
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My 82 LS did not have washers, but I am not 100% certain that they hadn't been touched/changed at some point by the PO or the PO's dealer.
I put in new ones, and basically crank them about as tight as I can with the little toolkit wrench - I don't have an adapter for my torque wrench to fit in there, but I am pretty sure that those bolts are NOT going to come loose.
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The shop manual calls for a torque specification of 27 +3 ft/lbs. if anyone was wondering .
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No lock washers or wave washers underneath the driveshaft flange bolts on my '83. I used a 10mm 12 pt wrench with a shorty cheater bar to break them loose. I was wondering about how to retorque the little rascals so I'm glad there is a tool out there. Ooooo, new tools, my favorite!
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My '86/'87 came apart without the washers. I found the special 12 point torque wrench adapter at Northwoods Airheads
www.northwoodsairheads.com
It comes with instructions on how to adjust your wrench for the added length.
Of course this is really for the owner who is uncomfortable with the typical German torque setting "Gutentite". Or those of us who are just a bit "anal".
[smiley=dizzy2.gif] [smiley=dizzy2.gif]
Ed
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I use the gutentite method WITH blue Loctite. I have a Snap-On 10 mm combi wrench that is about 10-11 inches long and I just give a couple of good grunts on it and it's always seemed to be enough!
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Well, I put my reply on the hijacked thread...
I always thought the bolts had to be replaced because they are stretch bolts. I've always replaced mine.
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Well, I put my reply on the hijacked thread...
I always thought the bolts had to be replaced because they are stretch bolts. I've always replaced mine.
That's the official way. It's not like they are expensive. But I doubt reusing them would make any problems, providing that you make sure that the threads are good by putting them in hand tight until they meet the flange. Then pull them out, use the blue loctite, and tighten them.