I'm refurbishing these now prior to starting my new workbench.
Here they are the one in the foreground Is already stripped apart. It's a straight forward strip, first you knock out the split pin in the end of the turn screw central bar, then remove two small bolt that hold the thumb quick release lever in place and slide it all apart, ready for cleaning and refurbishment.
Most of the cleaning is either old grease someone used in the past, or oil and dried sawdust which over time clogs up the drive threads making it difficult to use your vice but, as seen in the above photo the glide rods are rusted up and this definitely needs cleaning off, it's so when you use the thumb quick release lever to open your vice it will glide out and you don't end up having to tug struggling to pull it out.
Here are all the components cleaned up and lightly sprayed with WD40 to keep the rust off while I spray on the first primer coat to the main framework of this vice.
Primarily the most important part of the vice is the back half of it, the part that bolted under the bench and out of sight and forgotten about, really it's the vices gearbox and should be taken good care of. as seen here. With a refurbishment this is the most important part from here on, the six holes must be bare metal, ie: no oil, grease mucky sawdust and definitely no paint.
How many of you have actually checked on this, especially if it,s been bought second hand probably it's been slapped all over with paint, then and a ton of oil and grease splattered all over to get it to work somewhere near how it should be.
Another most important part shown left above here with the aid of two pencils, these are two machined faces where the clutch site snugly between, also to be kept as bare metal, Once these and the holes are all cleaned your now ready to do a partial rebuild. Before you go mad and totally rebuild your vice now assemble it to this stage only.
Just place the end spacer bar (blue) on the ends of the glide bars to hold them parallel to each other, do not refit the spacer washer and split pin.
Now leaving the front end of the vice on the bench with your right hand pick up the end with the spacer bar attached to about a thirty 30 angle keeping you left hand out of the way the back half of the vice should now slide smoothly to full length of the glide bars under it's on weight. if it doesn't then more cleaning is still required.
I have use a piece of wood to demo this but as you see the vice has slide the full length under it's own weight without assistants.
At this stage both glide bars and holes are perfect so on to the rebuild of the clutch. The clutch while it's engaged you can only wind the vice in or out by hand, disengaged the clutch using the lever, As you engage the lever it raises the clutch off of the main screw bar allowing you to pull it open, or push closed, when you release the lever the clutch re-engages stopping you pushing or pulling any further.As seen here.
Here left in the photos shows the screw bar with the clutch sat snugly in the spiral screw, While in this position the clutch is engaged.
Ok clutch sat in it's housing with the spiral thread underneath waiting for the main clutch housing to be bolted over it. Right looking straight on the end of the vice here you see the clutch housing bolted on, the end of the flat bar is in the horizontal position (clutch engaged) the left side of the bar is inset into the side of the shaft on the clutch which when the lever is engaged lifts the clutch, disengaging it, but, (NOTE) on the right side a finger of metal that is part of the clutch housing and must be under the flat bar this stops the flat bar from turning downwards thus giving the left side of the bar greater lift to disengage.
The assemble of the clutch housing, this is fiddly, bear in mine the lever has to be in about the 2 O clock position when the vice is in it's normal working position, when you move the lever to the 2 0 clock position it's now under pressure from the return spring situated on the rear of the face of the vice.
Now you have to hold that pressure while at the same time as your assembling the clutch housing trying to get it over the clutch shaft and at the same time getting that finger of metal under the flat bar It's difficult it's fiddly but can be done, you may need two pair of hand and it may take several attempt, you will swear at it to get it into the right place and bolted back together, good luck.
Now you can fit the two spacing washer and split pin, your now completed.
Just to prove it does run smoothly, blink and you will miss it. here There you go, one down one to go.
It's now painted and finished.