The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: RSMike on April 25, 2013, 03:34:59 PM
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Every thing was going well with my fork seal replacement and gator fitting when this happened. I only tightened up to the specified torque with a torque wrench (9nm) but it was too much.
I think it was already a bit dodgy last time I replaced fork oil but I forgot about this.
The only way I can get any purchase on it now and tighten up is without a crush washer, which probably is not going to work.
What are my options?
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Drill the hole over size and use a larger diameter bolt .
Don't know if a 'helicoil' or threaded insert type repair will work in this application, due to not a lot of metal thickness in the area .
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May not need to drill but simply use a bottoming tap to go up one size. Use that crush washer.
As you've discovered, the aluminum is easily stripped by steel threads... and the manual torque rate is way too high. Snug is good enough for gubmint work.
Drain the fork oil to wash out aluminum swarf. Pump the front end to get a good squirt. She'll be fine, mate.
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Hello An Heli-Coil (TM) will fit. I have at least one in place.
In the mean time you can put Drei Bond or Hylomar sealant instead of the crush washer and see where it goes.
Ihad the same issue when last replacing the fork lip seal..... So I had to dismantle again and go to the shop to have the helicoil fitted. If you are gentle the seal won't be hurt.
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May not need to drill but simply use a bottoming tap to go up one size. Use that crush washer.
As you've discovered, the aluminum is easily stripped by steel threads... and the manual torque rate is way too high. Snug is good enough for gubmint work.
Drain the fork oil to wash out aluminum swarf. Pump the front end to get a good squirt. She'll be fine, mate.
I have a tap set that starts at M3, any idea what size this thread is?
I might try the sealant like George suggests as a temp fix in the meantime, see how that goes
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M6 I think if I'm not mistaken. Better check with an M6 nut before making mistakes. ...
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suecanada did this AGES ago. Same thing - using a torque wrench.
A torque wrench is BAD NEWS on this particular fastener. Not only is the manual's figure too high, but when one only uses technology and "a figure" (especially with steel into aluminum), it is bound to mess up.
This is definitely one fastener that needs only "feel". And snugged up, as mentioned above.
If it leaks, you can try tightening a little more (NEVER with anything more than the small 10mm box-end spanner). If it is still leaking, I would try some sealant.
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Rob's right I did this stripped bolt on the front fork ages ago and tried an helicoil that never worked as it came out next time I tried to change the fork oil...came out all broken up. So I used sealant and have never changed the oil since!
So Monte what do you mean when you say "use a bottoming tap" and go up one size. I know about going up one size but what's a bottoming tap??? Derek has taps and dies in the workshop....do you mean I pick one that is slightly bigger whatever that would be and screw it up that wee hole??? :-/ :-[
As Rob says Only use the 10mm wrench in the tool kit and just breath on the other end for a just-snug fit. The other 10 mm. bolt I never touch is the final drive oil check bolt at the rear of the final drive. I am convinced I'd wreck it just looking at it! Paranoid...nah...hah!!! I always empty the final drive into a measured beaker and either put it back in the final drive or replace the lube if needed. Good way to keep a check on lube migrating from final drive into driveshaft in any case. I seem to be always short of final drive lube but I think mine is leaking out not migrating I guess.
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Hi Sue. A lot of taps have a taper to aid it getting it started but the downside is it has to go through the material past the taper to cut full threads all the way to the end. The result is the tap would extend all the way into the interior of the fork tube, increasing the amount of aluminum swarf that could inside.
A bottoming tap has straight sides and cutting threads all the way to the end, allowing you to thread a blind hole all the way to the bottom. In this case, with careful use, you could re-thread just to the length of the existing hole without the tap intruding into the fork leg, minimizing the amount of foreign material that you have to get out.
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Good on ya, Marc.
I'm up to my ass in landscaping projects and have had little time for the compuKer.
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OK, thanks all for all the info.
I did the temp fix with sealant and no washer. I have refilled the fork and no leaks, though I have not ridden it yet. I did give it a few good compressions though ans so far its holding
If it holds I will leave it until next time. When it needs doing I will take the slider off and tap it. That way I can rinse out any swarf. I forgot to measure the length of the bolt before I closed it. If anyone knows the length, that would be great as I can then source one to be ready to do the job next time.
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Is the fork tube just a plain cast aluminium?
If so you could probably take it to (or do it yourself) a welding shop and have them fill in the material a bit. Then drill and re-tap. If it is electrically welded (as opposed to gas) your weld should be considerably (at least with steel it is 2 times) stronger than the base metal, which should give you some insurance in the future.
Be careful tapping aluminium. The tap will turn easily, but aluminium will gall much easier than steel.
Also, if you have impact tools or feel like dropping your extended socket down an open upper fork tube, you can always drain oil out of the piston retaining bolt hole through the bottom of the fork.
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Thanks, mentioning welding, The other solution I saw on another forum was blob of jbweld in the hole, then screw in the bolt. When well set gently back out the bolt and you should have new jbweld threads?
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Thanks, mentioning welding, The other solution I saw on another forum was blob of jbweld in the hole, then screw in the bolt. When well set gently back out the bolt and you should have new jbweld threads?
That sounds tacky. (tee hee)
I don't think I would do it to my bike. JB Weld junk inside of the fork leg?
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Hello !
Left hand fork has an HeliCoil since the early 90's. Right hand fork leg has it for less than a year.
They are still strong...
I think it depend on the quality of the new thread. If you have removed too much metal, then when threading, the tolerances are too wide and the HeliCoil is not held firmly in place..
But i can be mistaken ;-)
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Follow the installation instructions and install the helicoil insert with a permanent loktite to stop it winding out next time.
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Repair postponed for now as luckily seems to be holding, did a short ride on a bumpy back road and no leaks yet.
I guess if I did tap up I would need a new plug with the same head size, as the area to seat the washer and head can't be any larger, maybe thats why helicoil is better?
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fi719.photobucket.com%2Falbums%2Fww198%2Fmiketruss1%2Ff-plug.jpg&hash=b0514e8ecb3afffc40ed4779c679fddc003225e1)
I wonder if this kit is what I need?
http://tinyurl.com/br2wmmr
On the positive side, happy with the gaiters:
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fi719.photobucket.com%2Falbums%2Fww198%2Fmiketruss1%2FIMG_0084.jpg&hash=a4f5cf1229129a98208d14075ee6ae2fc9fe0477)
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Yes, the Ebay thing is the good one. As the thread tool is tapered, you'll need a complete disassembly of the fork leg and a thorough cleaning afterwards.
Last but not least put a nylon tie to keep the screw on the leg. If during riding the pressure ask her to leave, she will get help from the tie ....
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Last but not least put a nylon tie to keep the screw on the leg. If during riding the pressure ask her to leave, she will get help from the tie ....
Nice idea George, thanks, I will do that.
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Mike,
sounds like you are eventually going with the Heli-Coil, but it you decided to tap up a size and were worried about clearance around the head of the drain plug bolt you could probably use a socket-head (allen) bolt instead of a hex-head bolt.
And BTW, I like the gaiters.
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Yes, thanks, I ordered that helicoil kit today, I'll do a dry run first on a bit of scrap aluminium casting before I try it on the slider.
Though the allen head bolt is also a good idea that I had not considered.
The forks got a good test this evening, some confused car driver I was tailing couldn't decide which exit to take off a roundabout, so he slammed on the brakes midway between the two to consider a bit longer. First time I managed to lock the front wheel on the R65, It started to go sideways but I let go and it recovered, otherwise I was off, >:(, much profanities muttered in my helmet!
Anyway still no leaks, but I had George's zip tie in place so it might have helped.
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Glad to hear you have good brakes and tires! Gotta watch out for fools!
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Good on ya, Marc.
I'm up to my ass in landscaping projects and have had little time for the compuKer.
Wondered why it was so peaceful around here! [smiley=ROTFLMAO.gif]
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Good on ya, Marc.
I'm up to my ass in landscaping projects and have had little time for the compuKer.
Wondered why it was so peaceful around here! [smiley=ROTFLMAO.gif]
Funny, Justin. If my fingers n' toes weren't so cramped up from all the dirt shoveling, I'd try to think up something witty...
However, I do have some plumbing chores that need attention and I hear that you are the Zen Master of the Pipe Wrench for all things waste drain. Wanta join for some fun? ::)
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Good on ya, Marc.
I'm up to my ass in landscaping projects and have had little time for the compuKer.
Wondered why it was so peaceful around here! [smiley=ROTFLMAO.gif]
Funny, Justin. If my fingers n' toes weren't so cramped up from all the dirt shoveling, I'd try to think up something witty...
However, I do have some plumbing chores that need attention and I hear that you are the Zen Master of the Pipe Wrench for all things waste drain. Wanta join for some fun? ::)
Oh yeah - nothing like laying upside down on your back under a sink. :P
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I have been searching for fork gators for my 82 R65 cafe conversion. Yours look great. Could you tell me whats size and where you got yours?
Thanks for your help :)
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a few years ago a dealer did a repair to a thread with something called a 'time sert' , similar to a helicoil but solid and bonded in and much stronger than a helicoil, when i use helicoils i usually use a strong thread bond of some kind .
http://www.timesert.com/ here you go ;D
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I have been searching for fork gators for my 82 R65 cafe conversion. Yours look great. Could you tell me whats size and where you got yours?
Thanks for your help :)
Thanks, I got them from Motobins in the UK, here is the link:
http://www.motobins.co.uk/displayfinal.php?q=93900&topsearch=1&go=GO
also don't forget to order 4 of these:
http://www.motobins.co.uk/displayfinal.php?q=60590&topsearch=1&go=GO
Mike
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a few years ago a dealer did a repair to a thread with something called a 'time sert' , similar to a helicoil but solid and bonded in and much stronger than a helicoil, when i use helicoils i usually use a strong thread bond of some kind .
http://www.timesert.com/ here you go ;D
That looks good, I like the flange. But I already ordered the helicoil and did the job today.
Seems to have gone ok.
Some pics in case anyone has to do this job again:
(1) Drill and tap (M6 helicoil kit), with 5mm helicoils (I got from www.motorsport-tools.com)
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fi719.photobucket.com%2Falbums%2Fww198%2Fmiketruss1%2Ftap.jpg&hash=f8730d5729dc40eef9a2f89ffbdda160244845c1)
(2) Tapped hole:
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fi719.photobucket.com%2Falbums%2Fww198%2Fmiketruss1%2Fthread.jpg&hash=fc910d61a1cf32b8852ce2ad5304a4feced3e848)
(3) Amazing amount of swarf to rinse out of the hole and slider (looks gold because its in oil):
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fi719.photobucket.com%2Falbums%2Fww198%2Fmiketruss1%2Fswarf.jpg&hash=6b7437bf47848e18048676cf169ca07bec71c6a1)
(4) Helicoil inserted, be sure to go flush or just below surface. I did put some lock thread on the coil and leveled off rough spots on surface (not yet done in this photo).:
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fi719.photobucket.com%2Falbums%2Fww198%2Fmiketruss1%2Fheli.jpg&hash=8ee4a7934b3ba2f56ecd8a1ecabeeb3471d616ae)
(5) Break off the tang that you used to insert the coil and retrieve from slider!
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fi719.photobucket.com%2Falbums%2Fww198%2Fmiketruss1%2Ftang.jpg&hash=2748ea05d4ee856d7e6bb6197e11de6c3c52d682)
(6) I went with a copper crush that I felt had a better surface area
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fi719.photobucket.com%2Falbums%2Fww198%2Fmiketruss1%2Fcrush.jpg&hash=b2b89298a44e4c0c692f16b16155ba85b3788c82)
(7) And the thing I will not forget ever again!, Just snug with the drain washer.
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fi719.photobucket.com%2Falbums%2Fww198%2Fmiketruss1%2Fsnug.jpg&hash=2c413d9279fe55400a2fbae99da797532c84cb08)
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Excellent work, Mike. Nicely played. Your post should help others whom experience these stripped aluminum thread issues. [smiley=thumbsup.gif]
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i wish i'd a pound for every helicoil i've done! lol! jap alloy is even softer!
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I am probably going to get heaps of scorn and safety concerns here but as a 'temporary' fix for this problem on the R65 I have to admit I used plumbers thread tape. So far (5K) the bolt has held and no leaks.
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My first bike was a Yamaha XS400 Maxim. Got it right out of high school and I didn't know a thing about wrenchin.
Drain bolt was cross threaded, so when I changed the fork seals, I couldn't get the thing to hold oil anymore. I used a stick of plumbers epoxy and mounded it over the bolt head!
It really wasn't that hokey when you considered that one of my MC reservoir cover screws was snapped and replaced with a zip tie.
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Don't know if a 'helicoil' or threaded insert type repair will work in this application, due to not a lot of metal thickness in the area .
It will. I stripped one years back and used a Helicoil "clone" to fix. the trick of it is to carefully count the number of turns available and to then use an insert cut to just *less* than that number of turns and to use loctite "studlock' or equivalent on the insert - otherwise it may leak past the threads. Of course do not insert the drain bolt for 24 hours to make sure that the studlock as gone off first.
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I also have HeliCoil at this place and it's both fit and sealed. I put a little drop of Drei Bond on the thread in order to be able to reduce the torque applied to the screw while retaining the oil inside. I do not want to strip it again...