Reassemble the cartridge and connect it to the base valve in the fork leg
My tuner has freed my rebound needles and reattached them to the piston rod. Now I have to reassemble the cartridge by carefully inserting the assembled piston rod (w/ ring) into the tube. If you followed the manual you would then have to apply some blue Loctite to the screw sleeve threads and tighten it to the tube. (Odd how many fittings do not list torque values in here.
) If you followed the tuners’ advice simply slide the assembled piston rod into the tube, up through the screw sleeve (don’t forget the piston ring), and thread the hydraulic stop on “hand tight”.
Remember the cartridge threads onto the compression assembly and that secures them to the axle clamps at the base of the fork tubes. Wipe a bit of fork oil on the compression assembly’s o-ring and you are ready to put them together. Don’t forget the manual’s tip to extend the piston rod and bend it to one side in order to keep the cartridge from rotating while you thread it onto the compression assembly. I believe that is a 25Nm torque value.
Pour in oil/set oil height, install springs, and fork caps
This is where folks who skipped out on “further disassembly” above join back in with the game.
First I’d recommend you practice keeping the piston rod up while installing the spring before you pour in the oil. See the next paragraph for details. This will save you some hassle, but only if you remember to remove the spring before pouring in the oil… remember the oil height is set without the springs installed!
OK, ready to pour in oil? You will need some way of standing the fork up while you fill it partially with oil, then gradually pump the piston up and down filling the cartridge with oil to release any air bubbles, and then measure the oil height and finish filling it. I used some space between two palettes and a storage bin to hold my fork tube upright:
I poured in one bottle of Redline’s suspension fluid to fill the cartridge and then used part of a second bottle to set the oil height. I used a short metric ruler (15cm) and a camper’s headlamp to measure the oil height. HERE
is one thread showing the owner’s manual’s guidance to setting the oil height.
Figuring out how to install the springs while keeping the piston rod up, or how to raise it back up, can be hard the first few times. I know, I know, this is a common problem; no need to dwell...
Either extend the piston rod all the way up and then slide the spring over it, or use string to pull the piston rod up thru the spring. You can quickly, but in a controlled movement, slide the spring over the guide and then catch the piston rod before it falls down. If it falls down too far to catch through the top of the spring one tuner said catch it where you can by bending the spring slightly and then use your special spanner on the hydraulic stop’s nut (the one on the spring guide that you use to remove the fork cap) to “screw” the piston rod back up by rotating the spanner around the spring.
OK, push the spring down and get your spanner on that nut so you can thread on the fork cap, which should also be torqued to 25Nm I believe. Now you can raise the fork leg tube and thread it onto the fork cap “hand tight”. That is all it needs because the upper triple clamps over this area and holds the two together. And that should do it!
If you want to read my notes on further reassembly of the front end take a look HERE
Also review Neduro’s Spring Bike Maintenance and Setup Guide
for specific tips on the LC4’s WP forks setup (i.e. dealing with stiction).
Hope that helps.
Here are a few HOWDIDs with some good (and a lil’ bad… ) info: Gaspipe’s Emig Damper and Triple Clamps
and Motolard’s LC4 steering head and fork service notes
In case you are particular about your Loctites here are KTM WP Loctite codes
A few random fork threads:
And a few Sag threads (some already in LC4 Index):