The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: fermin on May 18, 2010, 10:58:59 AM

Title: U Joint Boot Replacement
Post by: fermin on May 18, 2010, 10:58:59 AM
I can say and correct me if I am wrong, that replacing this boot and attaching the driveshaft to the transmission is the most nerve wrecking maintenance/repair task I've yet to complete.  It took a bit of dexterity and wheel / swing arm positioning to finally install all 4 bolts, now trying to slide the boot onto the driveshaft arm is proving as difficult.  Mr Fleisher in his website indicates the use of a tapered tool ie the nozzle of a silicone tube to aid in this job but no indication as to the methodology.
Any other tips/suggestions?
I have attached the swing arm bolts because I need to tighten the 4 screws, but this gives you less room to work with.
How about using a blow dryer to heat and soften the boot?
Thanks
Title: Re: U Joint Boot Replacement
Post by: Bob_Roller on May 18, 2010, 11:29:47 AM
It is one of the more frustrating jobs to get accomplished on the bike, so simple, but yet it just doesn't want to co-operate .

Warming it up might help .

My last time doing this, I tried  compressing the pleats on the boot, with very thin sheet metal (.005 in thick) wrapped around the boot, secured with a couple of ty-wraps, it compresses the pleats, and makes the boot expand a bit in length .

Worked for me, no telling if anyone else would have success or not .
Title: Re: U Joint Boot Replacement
Post by: Mike V on May 18, 2010, 11:48:34 AM
fermin,
Just got past this step on my 81 restoration.  First of all I sympathise with your struggle.  I had a most difficult time with the metal strap not quite fitting on the swing arm side of the boot.  The swing arm housing seems to be asymmetrical on my bike and not a perfect circle. I had to purchase a 35mm screw to replace the 25mm standard. But, my procedure was; first secure boot to the swing arm side.  Careful to be sure the boot is on correctly, on some boots, there is a top and a specific end to match the transmission. Second, secures the swing arm and pin bolts. You may want to stuff a clean shop rag in the boot around the drive shaft to stop an errant bolt or tool from entering the swing arm housing, I use a dry paper towel. I then just pushed the boot back with one hand as Bob described and started the 12 sided bolts mating the two flanges. I found the use of the torque wrench extension tool handy to reach in and secure the bolts. If you removed the foot brake lever to gain more room, attach it securely and find a helper to stand on the brake locking the rear wheel while you torque the bolts. Once that is done, you will find the transmission end of the boot to go on easily to the nicely machined circular housing.  Good luck and let us know how you do.
Title: Re: U Joint Boot Replacement
Post by: fermin on May 18, 2010, 12:17:40 PM
Thanks, for a while there last night I thought what to do if one of the bolts fell into the driveshaft.  I'll attempt it tonight trying to compress the boot as suggested.  I didnt know there was a top /bottom to the boot. Any markings?
Title: Re: U Joint Boot Replacement
Post by: Mike V on May 18, 2010, 12:45:59 PM
I can't remember what the lettering is at the moment.  It's a German term for top or up.  That lettering (if on your boot) should go up and towards the transmission case. I think it's something to the affect of "getrieb seite" some also show 'oben' for the upper side, if my recollection is correct.

To be sure go to Snowbum's web site and research it, I believe he describes it.  Or someone on the forum may be able to validate. I don't have access to my notes at the moment.  If needed I can check when I return home if you don't find what you need.
Title: Re: U Joint Boot Replacement
Post by: Bob_Roller on May 18, 2010, 01:45:09 PM
At one time, the word 'OBEN' was molded into the rubber .

I think oben is up or top in German .

Some members here have gotten the boots lately, with nothing molded into them .
Title: Re: U Joint Boot Replacement
Post by: Mike V on May 18, 2010, 02:14:00 PM
Bob, thanks for that note and alerting the forum. My boot, had no markings as you mentioned and was a bit puzzling to me since I expected to see lettering as my larger bikes boots.  I closely inspected the boot and found it perfectly symmetrical front to rear and top to bottom. Sorry I forgot to mention that folks. Depending on your supplier and the shelf life of parts - I would suggest an inspection. Just to be sure.  Did I just complicate this issue for no reason?

Thanks for the clarification Bob.
Title: Re: U Joint Boot Replacement
Post by: Rob Valdez 79 R65 on May 18, 2010, 06:04:34 PM
A thread from January: http://www.bmwr65.org/cgi-bin/yabb2/YaBB.pl?num=1264726308/5#5
Title: Re: U Joint Boot Replacement
Post by: fermin on May 19, 2010, 01:33:42 PM
I should have searched the forum....  I couldnt find 'oben' or any indication as to orientation, and its installed...  If I look now and find it in the wrong positionI'll have to rotate it in place, cause that rear seal was a big pain.

Powered it up yesterday and the neutral light came on (I had replaced the switch while the  tranny was out) but stopped working the next time I turned the key.  Maybe I burned the light bulb