FJRoss wrote: ↑Sat May 30, 2020 10:16 pm
Fixed a leaky fork seal on my 2011 - Seal-Mate to the rescue! I was hoping to avoid replacing seals and bushings this time.
I have done forks before on my '07 with the help (and tools) of a fellow FJR owner in Vermont. The forks on this bike have Traxxion AK-20 innards and I was wondering if anyone had any experience with bushing/seal change with this setup. Should be easier getting them apart since Traxxion doesn't use the middle bushing. Reassembly without the middle bushing should be easier.
Any tricks to taking out the AK20 cartridge? I assume that has to be done before taking the forks apart.
Can the top bushing be inserted without using the thin wall metal pipe?
What fork oil? I think Traxxion suggests Maxima 125/150 (7wt). I have used Belray 5W in the past. Easier to get around here.
Hope to avoid doing seals this year, just oil if I can get away with it.
Ross, sent you a PM..... expanding here. First, the AK-20 cartridges are simply a bolt in replacement for the originals, proceed as normal.
Not having a middle bushing should make removal easier, but the FJR top bushings are way too much of an interference fit IMHO. Heat the lower tube in the bushing area with propane torch until quite hot, hope bushing doesn't expand as much as the aluminum, slide hammer away.... worst that can (and has on Gen1), is lower bushing comes off the tube and you end up prying/bending the upper bushing in past the "split" and get it out that way... of course, hopefully the seal came out, but seal pry tool works then (or big screwdriver).
We can debate the merit of the middle bushing all day.... never see them worn much, mostly destroyed on removal. If I had a scrap lower, I would section it for scientific purposes to see design theory. These days I tend to think OK to leave it out, although anal me always has replaced them. The lower bushing takes the heat and wears the fastest, but at say a 30k replacement interval, wear depends on mostly the aggressiveness of the rider. I've seen everything from barely worn to completely worn (on forward and rearward surfaces, no teflon, down to the copper.... and nobody noticed anything bad in performance. What are we talking with Teflon gone, a coupla three four five thou, worst ten? Relatively speaking, the lower bushing is a sloppy fit anyway, rides on a cushion of oil in the lower.
I would go with Traxxion's recommendation of 7W, Yamaha has a 7.5, or mix a 5 and a 10 in the same brand. I wouldn't go 10 although many have with OEM cartridges. No need, there's plenty of damping adjustment and the OEM valving was designed for 5W, and the OEM Yammy oil was really something less than that.
SealMate will get you by for a while... depends what got in there, just dirt/grit or bug guts damaging the seal lip... you're gonna replace them at some point sooner than later, IMHO. OTOH, you have nothing to lose by simply flushing and replacing the oil for now... if it leaks in not too many miles, re-use that oil if it's not dirty.
Another topic of interest... other bikes sometimes recommend greasing the seal, which leaves grease between the two seal lips... I haven't done it as a regular practice... is there merit to that grease staying in place and not letting dirt in? Or was it intended to be a lube for less stiction? Upper dust seals usually are in good shape and debatable if they need replacing but we always do... they keep the big rocks out, LOL. The main seal does the work.
PS - Just had a guy in another sandbox GixxerJasen his forks, jammed the lower bushing into the middle one, could not get the top one to budge, could not hammer the inner tube back down... eventually did with a lot of swearing and pounding, and twisting had inserted the axle shaft to hold it... lightly scored his lower tube, not awful, ended up with spiral marks.... will lightly hone and move forward. Jasen thinks he's special, LOL, but he ain't the only one... been there myself but I somehow managed to fix it.
PPS - The brilliant FYB method of seal removal.... big hydraulic press, fork filled with ATF, press only until seal slides out... not that messy. Wish I had one, that FYB is kinda brilliant but don't tell him, his hats get to be a tight fit when you do.