COMPLETE Fork Slider Rebuild Info
Bought a 2000 KLT with Hannigan 2+2 back in October - and the slow speed wobble finally got to me. So time to pull apart the front end and look for the source(s).
Hmmm. That steering damper appears to be useless. Time for a rebuild. So who put this thing together with goofy star bolts made out of German cheese, then decided to glue it together with holt-melt glue to add a little strength? So I had to remove wheel, calipers, and both halves of the fender to even access the upside-down bolt holding on the steering damper. After heating it thoroughly to melt the original hot-melt Locktite, I still managed to strip out the cheese head, even using an impact driver. A drill bit took care of the problematic roundy-roundy bolt head, and a new set of seals for the damper and some fresh oil seem to have solved that issue (thanks to those that pulled that information together). And a new ALLEN HEAD 12.9 bolt to replace the cheese.
There was a spacer below the fork brace, to make steering on the rig easier. One of the 12.9 bolts holding it on (aftermarket, in this case) had sheared off slightly below the shock slider boss. Nothing that a 12" drill bit and easy out (in conjunction with judiciously applied heat) couldn't remove.
Since I was this far, it only made sense to rejuvenate the rest of the fork slider parts (especially given the mother-lode of sparkly gold I got when cleaning all the accumulated muck out of the bottom of the fork slider (pic).
I pulled off the fork wiper, fork seal retention ring, fork seal and support washer. Looked at the upper bushing, but didn't see any wear to justify the gold flecks. The BMW parts fiche shows NOTHING below that top bushing. A Google search found NOTHING about anything below that top bushing. My eyes could see that there were white plastic spacers below that upper bush - and I assumed a lower bush as well. But the bike is 15 years old, and there is NOTHING out there on a lower bushing. My local BMW shop, and a BMW expert also claimed NOTHING below that bushing. But that just didn't make sense - new-fangled Telelever suspension or not. So I dug deeper (removed upper bushing and 4 plastic spacer tubes). And even took a picture (hard to do looking into a tube using a mirror). But here's a picture for those non-believers (pic). Will take some orientation to see what's there...
So the next question is, how to remove it? Ran to the hardware store and bought a 3 foot section of 1/4" steel rod, and filed the end flat (it was sort of a "mushed" profile, like it was cut with bolt cutters). Removed the drain bolt / o-ring from the bottom of the slider. Sprayed the inside of the slider with WD-40 and let it soak for 30 minutes. Flipped the slider and angled the rod up against the bottom of the lower bushing... tapped with a hammer, alternating sides so it wouldn't get cocked. It actually slid out pretty easily. In comparing the upper and lower bushing, the lower one had worn through the gray teflon coating and into the "gold" bronze underneath. The bottom one was 0.065" in the worn places, vs 0.077" for the unworn top bush. So definitely the source of my "gold". The better news is that BOTH BUSHES HAD THE SAME PART NUMBER STAMPED INTO THEM. (pics) So just order the same BMW part number for both the top and bottom bushing.
Here's an exploded picture of all the fork parts... (pic)
Re-installation... I have an old 27mm socket that I had had turned down for a Airhead swingarm pivot nut - and it looks like with a stack of 3/8" socket extensions (and proper lubrication) it should slide easily into place. A 28-30mm socket (depending on wall thickness) may work as well - YMMV.
I also found the nut on the front shock upper stud backed off (jam ut to follow). So at least three potential sources of front end funkiness so far. Hope that solves it.
Sorry for this first lengthy post - but wanted to publish this where someone else may be able to gain from my experience. Don't hold your breath, but maybe BMW will even admit to those parts actually being there eventually...