Originally Posted by Tbird
I was wondering how doable it is to rebuild the forks at home. If it's too much, could I remove the front fork assembly and take just it in for rebuilding? And should I rebuild/have rebuilt the left one that ain't leaking?
Anybody got any 'sperience with this?
The Repair Manual at page 31.13 shows what's involved with the seal replacement.
While I have not changed an LT fork seal, in the course of replacing my broken forks and bent telelever, I believe I've covered everything but the actual seal removal. I can take some pics of the seal bits from one of my broken legs if the manual's views are insufficient.
Maybe someone that's done the job will pipe in with other comments, but overall there doesn't appear to be anything "hard" about the seal replacement itself -- and in some ways it appears to be easier, since the fork has no internals (no spring, no dampener -- only a 1/2 liter of fluid -- ATF, IIRC). The manual shows a special tool to seat the new seal, but adequate care with an appropriately-sized socket should be just as effective at setting the seat squarely in its seat.
The real question is how do you want to approach the job? Unlike a convention fork, the fork lower legs can literally slide off the end of the fork tubes -- there's nothing holding them on except the fork bridge/telelever!
So, two options:
1. Remove only the leaking fork leg. Advantages: minimizes dissasembly; easy to handle. Disadvantage: Alignment on re-installation is critical -- the forks must be at 165mm (small tolerance given in the manual *and* the axle must slip-fit with light drag after you tighten the fork bridge/fork leg bolts (took me a couple tries before I was satified it was "right") -- a minor pita.
2. Remove the entire fork assembly as one piece: Advantages: Can't muck up the alignment. Disavantages: Requires releasing the lower ball joint from the telelever; much more bulky/awkward assembly to work with.
To release the fork tubes from the upper steering head, you need a thin 22mm open end wrench, like the one that used to be standard in the airhead tool kits, in order to hold the tube still while removing the retaining nut on the top of the tube.
Don't try to remove the 22mm cap on the top of the tube -- you can't without destroying the tube, and there's a fill hole right next to it anyway.
Be prepared to catch a *lot* of fluid -- 1/2 a liter is a surprisingly large amount. Even after my forks were snapped off and the bike left a Valdez-quantity of oil on Constitution Ave., I was amazed at how much was *still* in the forks when I did the repair disassembly.
Oh, and no on the left seal, unless you have some reason to do it, like excessive grit on the tube having scratched the tube and chewed up the seal.