RKT Diamond Drive Clutch Kit
1245 Industrial Park Rd.
Preston, ID 83263
208-852-3221 Fax 208-852-3228
1. Remove existing secondary spring by removing the cover, long plastic spacer, thin plastic spacer Under
stock spring), and plastic nut. ’07 models will not have the plastic nut. NONE of these parts will be re-
2. Purchase ANY CAT secondary torsion spring you wish.. We like the CAT Red/White (CAT part # 0648-
114), Speedwerx Blue, or Cat Sno-Pro Green Spring Part # 0748-025. but ANY spring can be used with
proper primary weights.
3. Remove the stock helix. To remove helix, we recommend using an impact driver (NOT AN AIR IMPACT
RATCHET but a HAMMER driven impact driver that can be found at your local auto-parts store) with a T-
20 Torx Head. It also helps to heat with a VERY DIRECTED SMALL flame on the helix where the bolts are
threaded. CAT uses heavy loc-tite so these can be difficult to get loose. For ’07 and ’08 clutches, you will
need to keep the helix under pressure and remove the 9 Torx head bolts located on back-side of the helix. Be
careful, the spring is tensioned and when the helix is loosened, it can shoot off and cause injury. NOTE:
There is a thin steel spacer washer that the stock , and RKT, helix rests upon. This OEM spacer has 9 holes
in it (6 on the ’05 clutch). This spacer MUST be used/re-installed or clutch damage will occur.
4. Take the new RKT Helix and take note of the machined vertical line in the side of the helix. Install the new
RK Tek Helix and put a few bolts in to hold it in place for a measurement. Do not fully tighten or install all
bolts at this time.
5. Take the entire clutch assembly and squeeze both sheaves together so they are touching (important).
6. With the clutch sheaves held together (Step #5), take a sharpie pen and make a mark in the spring area at the
bottom of the clutch. This mark should be inline with the machined line on the helix you noted in Step #4.
This sharpie mark needs to be located at the outer-most portion of the clutch casting (near casting hump).
This is the mark for the hole for the spring’s ear. Remove RKT Helix and set aside.
7. Using a long .250” to .275” drill bit, drill a .300” to .350” deep hole at your mark. Drill the hole as straight as
possible. Mark the location of this hole with a sharpie pen on the casted “hump” that you drilled next to.
8. Slide on, over the shaft, the aluminum bottom carrier and line up its hole with your hole drilled in step #7.
9. Make sure the thin, steel, spacer washer (step #3) is installed.
10. Install the RKT Custom Helix using the 9 bolts (supplied). Loc-tite (BLUE) all 9 bolts. Make sure the drilled
hole still is aligned with the line you drew in Step #4.
11. Install 4 studs (supplied) in top of helix. Loc-tite (BLUE) these.
12. Install supplied bushing in RK Tek Billet Clutch Cover. This bushing installs from the bottom (spring) side
of the cover. Install snap ring clip to hold bushing. This step may already be completed as delivered.
13. Install spring over shaft and place ear through bottom carrier into drilled hole (Step #7).
14. Place Billet Cover onto spring’s upper ear in the cover’s middle hole position. While holding downward
pressure, twist cover/spring until it locates over the 4 studs. Make sure that the spring’s ear remains in the
drilled hole when doing the twisting. Install supplied ny-loc nuts on studs and secure. NOTE: You will be
winding the spring as you twist the cover to the studs. Do not over-tighten the ny-loc nuts! You need to wind ndthe cover to the 2 stud (about 90 degrees). DO NOT drop cover on closest stud!
15. MAKE SURE that the mark you made in step #7 is still aligned with the bottom spring ear.
16. Install Black Diamond Quick Adjust Belt Deflection Adjuster (supplied). This adjuster is Left Hand Thread.
So, turning it to the left is tight, right is loose. Do not use ANY washers behind this adjuster. Tightening the
adjuster will push the sheaves open allowing the belt to rider lower in the secondary. This increases belt
deflection. We recommend setting the belt deflection to about 1” with light pressure. If your belt is
“squealing” at idle, you will need to turn the adjuster to the left until the squealing stops. If you get your
deflection too loose, you will have a very “soft” low end. Try and set deflection to a point where the belt will
just lightly squeal.
17. Install supplied allen head bolt, with washer. Tighten bolt snuggly (21ft/lbs) against the belt deflection
adjuster. This bolt holds you clutch on the shaft. Loosening this bolt is required to be able to turn the belt