Nige

Intriguingly neither the scroll nor individual worms are visible in your photographs. My first impression is that this is an independent 4 jaw chuck (and you state that), but if it is independent I wonder why concentricity is even mentioned.

On closer examination I see that the jaws are reversible so it is an independent chuck (also the scroll if there was one, would struggle to rotate with those four bolts passing through it!).

In use, when you take out the jaws to reverse them you are in fact 'dismantling' it. Taking all four jaws at once allows you to give the worms a good clean and apply a little oil (stand to the side and run the chuck at a fair like to throw off the excess) enough will remain to lubricate the surfaces.

Regular cleaning and lubrication is a good thing although i can very clearly remember from my schooldays being told that bike chains should never be oiled, because it stretches them!

Ian P

Take it apart, you ain't going to do any damage. At the end of the day it is only two lumps of cast iron with four screws holding it together. Yo can give it a good clean and grease and also find out how it works. Give the screws a good dose of penetrating fluid and use an appropriate screwdriver, if the blade is too narrow you will bugger the screws. Go for it, its a learning process.

You have no need to remove it from the back plate. Doing so will not show any innards of the chuck and there will be nothing to clean or lubricate

Roy ( If it's not broke, don't fix it )

But it looks nicer if you clean it up….!

Nige,

If you are taking it apart, make sure you mark it so the same holes are used. Centre punch the backplate and chuck body so they can be realigned.

Hugh

I have a six inch four jaw, that, from new, felt a bit odd sometimes if the the jaws were moved far. Eventually I removed the back plate and then the countersunk plate covering the works. The stuff that came out, disguised as grease, was all gritty when rubbed between the fingers. Awful stuff! It was almost as if it had been sabotaged. All fine now with new grease. Take it apart; you don't know what you may find. It would be quite difficult to damage it in the process and you will know that its all clean.

Remove jaws, noting their position. Also remove scrolls and also noting their positions. Those are the only parts to dissemble. Clean all well and reassemble. You can't have chuck parts too clean. Clean especially if you have had material that leaves abrasive swarf behind. Like cast iron or high silicon aluminium alloys etc. It won't wear out because you cleaned it. Neil

A reversible 4-jaw like this is dead easy to clean, and the dismantling procedure is no different from reversing the jaws. If it's a quality chuck then all the jaws, and their slots, will be numbered so it's a simple matter of matching numbers when reassembling. Looking closely the photo i can easily see the numbers 2 and 3 stamped on the face of the chuck beside their respective slots, so the others will be easy to identify. When you take out the jaws just check that they have matching numbers (mine were stamped on one side). If not then the ubiquitous Sharpie pen will do the trick. The adjusting screws may not be numbered (mine weren't) so it would be best to tie them together with their respective jaws with a twist-tie until you are ready to clean them. Make sure they stay together when cleaned. I found that some of the adjusting screws were a better fit with one jaw than another. If they do get mixed up then a bit a trial and error will soon get you to the smoothest combinations.

Cheers.

Hi Phil,

I did try oil as lubricant on one of my chucks, had to clean the walls after the first run, so except for the one test, I have been using a "moly grease". Yes, swarf has a tendency to stick to the grease so I try to protect the "innards" of the chuck with a rag.

Thor