4mm Valve Chuck Disassembly / Assembly Tool

PN: 012-1054-60


[This tool is required to perform the following operations]


Disassembly Instructions

STEP 1: Remove the chuck cover from the Chuck Bearing Assembly, being careful not to pull any wires from the cover.. 
Rotate the Chuck so that the Grind Mark on the front collar and the Yellow Mark on the Spring are Vertical as show 
in the photo below.


STEP 2: Remove the (3) three 8 x 32 x 5/16 slot head screws from the Chuck End Cap (Black) shown below.



STEP 3: Use the Disassembly Tool (picture at the top of this document) which is standard equipment with your machine, 
put the 8 x 32 screws (3) into the chuck shaft in a 1/4 of an inch. Put the 1/4 x 20 Hex Head Bolt finger tight against the End Plate.


STEP 4: Remove the Chuck Yoke.


STEP 5: Loosen the 1/4 x 20 Hex head bolt counter clockwise. As you release the 1/4 x 20 bolt, the spring pressure 
should begin to release.. NOTE: You may need to soak the chuck in Automatic Transmission Fluid to remove grit and 
make the collars slide easier.


STEP 6: Remove the Chuck Disassembly Tool.


STEP 7: Begin to remove the outer collar from the chuck shaft. Next, remove the Loading Cup with the Four (4) springs. 
The large spring and inner collar will be removed along with the Thrust Step Washer. As you take the Inner collar off the 
steel chuck balls(9/16) may fall out of the chuck shaft.


STEP 8: Remove the Chuck Handwheel and belt from the chuck shaft. Remove the chuck from the chuck bearing assembly. 
Clean all parts with a parts cleaning solvent.




Assembly Instructions

STEP 9: (1) Put the shaft back in the chuck bearing slide, use transmission fluid only and coat the chuck shaft. 
Make sure the keys are vertical.


(2) Put the thrust washer, spring, and (3) three rear balls back on the chuck shaft, making sure that the Yellow mark 
is lined up with the Keys. hold on to the bottom balls so they don't fall out of the shaft.


(3) Slide on the Inner collar, so all three rear balls are inside of the collar.


(4) Put the front set of balls in the shaft. Install the loading cup with four(4) springs facing out.


(5) Install the outer collar, making sure the grind mark is lined up with the keyways.


(6) Reinstall the Disassembly tool. Put the three screws (8 x 32) in one quarter (1/4) of an inch. Begin to tighten 
the 1/4 x 20 bolt, making sure that the collars are still lined up with the keys. Run 1/4 x 20 bolt in until it is tight.


(7) Reinstall the Chuck Yoke.


(8) Remove the Disassembly Tool and reinstall the chuck End Cap with the three 8 x 32 screws.


(9) Reinstall the chuck Handwheel and Belt, making sure the chuck and chuck handwheel are snug to the chuck bearing slide.


(10) Reinstall the chuck cover. Make sure there are no wires touching the chuck.