Wilton 746 Questions

[gohunt]

I recently picked up a Wilton 746 that needs a little attention (I hope a little). The jaws will not fully close…by about a half inch. What’s the deal with that? I’ve fully removed the moving jaw and provided pics for what that’s worth.
Also, this vice has 2 lock downs on the rotation. Why is that? I don’t think I’ve seen any other vice with that feature.
Thanks in advance!

 

[paulsomlo]

You mean the pipe jaws? That's normal. As far as the lockdowns? Two are better than one.

 

[gohunt]

No, not the pipe jaws. The main jaws lack about 1/2” coming together.

 

[paulsomlo]

Can you post a picture from the side, showing the main jaws as well?

 

[RTM]

Things I would look at:

Is the screw clean, no thread damage at the last inches before the handle, looking up from the bottom of the slide?

Is the slide smooth, no damage in the section that should disappear into the stationary jaw? Could be anywhere except on the part that sticks out when it’s closed.

Is the slide straight, and square to the jaw?

 

[Nick Rivers]

Pull the spindle out of the dynamic jaw, then slide the dynamic jaw back into the static jaw without the spindle. That will narrow it down.

 

[RTM]

Pull the spindle out of the dynamic jaw, then slide the dynamic jaw back into the static jaw without the spindle. That will narrow it down.

I'm not familiar with that vise, does it use the retainer clip that disappears like a magician's rabbit, which is why I hesitate to recommend that. If a collar, go for it

But if you can safely do that, then winding the screw all the way into the nut would eliminate another concern.

If each works individually but the combined pair won't work then you have an alignment problem somewhere.

 

[gohunt]

Pull the spindle out of the dynamic jaw, then slide the dynamic jaw back into the static jaw without the spindle. That will narrow it down.

Did that. Seems impossible that the jaws will ever meet without shortening the square tube on the dynamic jaw. As you can see in the second pic there is an insert in the end of the static jaw side that is retained with 2 roll pins. Without the dynamic jaw, the “screw” will screw out further allowing the threaded end to extend through the insert. Apparently the square tube of the dynamic jaw bottoms out on the insert restricting the jaws from coming together. For sure, shortening the square tube would make the vise more usable, but, I don’t really think that is the right answer.

 

[paulsomlo]

Somebody "modified" the back end - the screw shouldn't stick out the end like that. From the looks of it, the back's been chopped up - did they weld the nut in? You probably need to either move the nut further back or cut off some of it where the spindle enters. Here's a picture of what it's supposed to look like:

 

[gohunt]

Somebody "modified" the back end - the screw shouldn't stick out the end like that. From the looks of it, the back's been chopped up - did they weld the nut in? You probably need to either move the nut further back or cut off some of it where the spindle enters. Here's a picture of what it's supposed to look like:

Well, maybe, but I don’t really see the difference between yours and mine. Mine looks so “aged” evenly that I don’t see there is any alteration on the end as you suggest.

 

[Jacobs976]

Check if jaws are perfectly parallel. Looks like they're potentially skewed on the dynamic arm which is an issue with the design. Over torque bends tube out of alignment with cast body and that could account for the mismatch with screw exposed by allowing over travel and bottoming out.

 

[gohunt]

So I sawed off 1/2” of the square tube of the dynamic jaw and I now have a functioning vise. I Can’t explain how this problem came to be but it was definitely worth giving up a half inch of the jaw opening distance to end up where I am.
The vise has been overstressed as Jacobs976 mentioned. The jaws do now come together but not perfectly. Certainly it can still be a useful tool. Thanks for the input!