I finally got around to reassembling the FD yesterday. While in town I stopped at an AutoZone to pick up an $11 tube of the "other" brand of
Blue thread locker. They did not have the less expensive liquid, so I got the gel. I already have several plastic vials red loctite.
When I started to clean the FD pivot bearings and inner races, I noticed a few hidden details that would greatly help anyone that also will do this job. The pivot bolt threads are 2 different sizes (between Left and Right). The Right side is a larger diameter thread and it allows the bearing inner race to be removed thru the threaded hole (that is important!). The Left side pivot bolt, with the big 30mm locknut on it will NOT allow the inner race to pass thru the smaller diameter threaded hole. Since the factory apparently puts red loctite between the inner race ID and the pivot bolt, you will have a hard time completely removing that bolt and it will likely cause thread damage just as the larger inner race butts against the inside of the swingarm casting just as the pivot bolt is almost removed. UNLESS you add 200degF heat to the bolt to soften the red loctite when it bottoms out on pivot bolt removal. This, I am sure, is what caused
Beemeridian's pivot bolt thread damage during his disassembly. The first time I took mine apart, there was red loctite on the threads AND between the inner race's ID and the pivot bolt. I thought it was a migrating sloppy excess, but red loctiting the inner race to the pivot bolt serves 2 very beneficial purposes.
1--It prevents the inner race from spinning on the pivot bolt instead of rotating inside the needle bearing, like it should.
2--It takes up any minute play between the 2 parts, adding solidity to the bike's handling.
I just checked the shop manual and it makes NO mention of putting red loctite between the pivot bolt and the inner race ID, like the BMW factory has done. Therefore, I didn't put any red loctite there when I had it apart recently for the input shaft spline lube. It caused the inner race to turn on the pivot bolt and score it's smooth ground surface! Apparently the cone shaped inner & outer bearing races have slight wear notches in them (after 63,000 miles) that held onto the inner race and made it turn on the aluminum surface of the pivot bolt instead. That minute turning, with high loads, scored/galled the smooth ground pivot bolt's bearing ID mating surface. Yes I could have replaced all the costly, less than perfect parts involved now, but the imperfections can be tolerated for the dwindling time I will own this bike*. Also, they all can be quickly replaced at any time "necessary" -after- I have all the noted replacement parts in hand.
Getting back to the reassembly,
you have to put the left inner race into the FD left needle bearing prior to plugging the U-Joint spline into the driveshaft, or you'll have to remove it again to get it in. That's because the FD inner race does NOT fit thru the (smaller) threaded hole! It will on the larger diameter right side, so you can leave that one off for now. OK. I lined up my red nail polish phasing marks on the mating driveshaft parts and struggled for 10+ minutes searching for the point of perfect axial/rotational spline alignment required for the 2 snug fitting parts to go together. A long thin screwdriver thru the right side threaded hole serves to lift the driveshaft to the correct level so it can plug onto the U-joint shaft. It was annoyingly difficult this time, but very easy the previous time I did this operation last fall. Go figure.
When it finally did go together and holding the FD in place with my knee, I put blue thread locker on the pivot bolt's threads and red loctite on the shaft portion that goes inside the inner race ID. Same for the other side too. You have to work quickly before the red loctite sets up, attaining full final assembly torque in less than 3 minutes. It sounds difficult but it's not. Just don't panic and whistle while you work. Be aware that the tighter the fit between the thread locked parts, the quicker it sets up. It will not harden if you squeeze out or spill a drop on a non porous surface. The drop will remain a liquid for many hours, even overnite!
Back to the assembly . . . . I applied 150% of the initial bearing preload torque and left it there for 10 seconds or so for the red loctite on the vertical mating surfaces of the pivot bolts to squeeze out to both their minimum thicknesses. Then loosened and reapplied the correct torque before immediately tightening the 30mm locknut. I had put a prick punched mark on the face of the left pivot bolt head before to see if it had moved after tightening the 30mm locknut. It does NOT, the 3 different times I've tightened that very same locknut. You do not need the $pecial hold'um tool. Just a referencing punch mark. The manual says to allow 3 hours for the red loctite to set up. Seeing how it was late and supper time was here, I gave it overnite.
The next day when I went for that 1st ride with the new bearings, the bike's amazing, full confidence, totally neutral, completely stable handling had returned!!!!
Going straight or digging deep in a corner at 2x the legal speed.
What a great feeling to throw it into a sharp corner going "fast" and have it feel so hooked up at ANY lean angle!
No more FD growling either.
* A new bike is planned this year! See my post in Off Topic.
!!
