View Full Version : chuck disassembly.....?s

10-21-2004, 12:34 AM
"TruJust" 5" six jaw. Got the back plate and adjusters all apart. Last to be removed were the smaller hex socket screws near center of face. How do you get the last two pieces apart? Scroll plate seems to be sandwiched between front and back plates. Are they just a slip fit or threaded together? Any 'tips' for getting the two/three pieces apart? Has only one 1/4" socket that runs the 6 jaws open or closed [jaws and all else including larger 6 bolts already removed].
thanks, alan in ga

10-21-2004, 03:04 AM
Just a slip "fit". Rap the body with a soft mallet around the perimeter. It may take a few go arounds. Don't use a sharp pry bar as tempting as it may be, you will just scuff the outer dia. and possibly wedge the inner dia. slip fit. JRouche.

10-21-2004, 07:43 AM
this chuck has been sitting for 15 years and adjustment ring cavity was filled with hardened grease with even a few chips embedded [got in how?]. I'm sure there is some 'grease glue' inbetween the two halves as well. Will try some mild heat [>200 degrees F]to soften the grease goo glue.
thanks. This chuck was a gift from someone I helped out with a rifle problem. Had to have a friend thread the universal adaptor that came with it to fit my Atlas 12x36 BUT,,,what a jewel of a chuck it IS! By the way, it is a "AjustTru" brand.

10-21-2004, 09:30 AM
I never like the use of heat with tooling. 200* isn't much, but I would still avoid.

If it is gunked up, squirt some WD 40 into it, around the jaws and open areas. Wiggle the key, working the scroll back & forth, and it will probably work loose.

Sometimes, VERY lightly tapping the key will start to separate the chuck halves. It can then be pried apart with a thin bladed tool like a putty knife.

When reassembling, I have used RTV in the gap between the backplate and chuck body to prevent chips from entering this way.

10-21-2004, 10:11 AM
it's been soaking in kerosene for a couple of weeks, I'll try some KROIL.
Jaws and back plate are off. Just the scroll plate trapped between front and back halves I'm guessing.

[This message has been edited by Alaninga (edited 10-21-2004).]

Mike Burdick
10-21-2004, 12:09 PM

Although I have never disassembled a chuck exactly like yours, most chucks I’ve taken apart have a split that goes thru the middle of the chuck tightening screws. To disassemble, I tighten the jaws so that they are near the center; remove all holding bolts; and then rap the center jaws lightly with a soft mallet. This usually will separate the two halves just a little and expose the scroll. Like said above, don’t insert a pry bar (screw driver) to start the separation as this will mar the surface and you will have a permanent reminder of that mistake.


[This message has been edited by Mike Burdick (edited 10-21-2004).]

10-21-2004, 11:32 PM
.....this WORKED~!
..assembled 3 of the 6 jaws [evenly spaced, 1,3,6]. Tried tightening the scroll on a piece of 1" stock,,no luck. Then took a piece of pipe and with those 3 jaws in center, 'contained' them on the outside by putting pipe center over them,,then tried opening with jaws pressing outward against pipe,,chuck halves split open!
Thanks,,now pass the brass wire brush and that can of kerosene,,,,yup,,old grease crud in there.

10-22-2004, 01:19 AM
Can't resist adding my two cents here, having just gone through the chucks I brought home last week.

I use the screws to separate things like these -- and it worked good with three 6" chucks I cleaned this week. Just back them out far enough to stand out of the hole, then with the chuck on edge, gently tap them with the end of a large brass drift to separate the halves. I think I used the larger ring of screws around the outside.

The really great thing about MY messy job (Dad's old SB H10, etc.) was stumbling onto this GREAT SITE, and learning about degreasers that don't stink or set the garage afire! While I was reading (that other thread) I realized that I had a gallon of Castrol degreaser that I had never even used (saved for cleaning the driveway).

Well, I put some in a spray bottle and the rest in my ultrasonic, and saved myself a lot of trouble. It was way better than kerosene; It works like 'gunk' engine degreaser, and doesn't stink. Sort of an oven cleaner 'lite'. This will be my standard 'tank' solution from here on.

Anyway, it really was great for cleaning out those old chucks -- I just kept a 5-gallon bucket of hot water on the floor under the ultrasonic, and lifted the parts basket into it for a quick rinse -- then the WD40, and brushing with oil.

(Next time I'm going to use the wife's Dr. Scholl's heater/vibrater foot soaker tub, instead of that dinky ultrasonic, and do it in half the time. Serious!)

10-23-2004, 04:04 PM
....ah.......what a nice chuck! Cleaned,,greased with MOBIL synthetic [red]grease, even with main bolts fairly tight, it adjusts to a light turn of the adjustment bolts. LOTS of adjustment now compared to before when it was locked up with gear 'goo-gloo'.
Sure makes 3 hours[+] of cleaning worthwhile. Old grease was like hardened Elmer's Glue! Had to take wood scrapes to get it off even after kerosene soaking.
All is well with clean machinery!
alan in ga.

[This message has been edited by Alaninga (edited 10-23-2004).]