need a fix for Grizzly "half nut" on bandsaw vise screw

[jwmay]

Any further conclusions reached here? I've been trying to get mine to work with no luck too. The quick release feature is much less important to me than the secure clamping. I may have to buy an acme nut as well.

 

[jwmay]

Just for anybody else that may wander to here:
My problem ended up being a worn leadscrew. After cleaning the chips and gunk out of the nut, my clamping problem continued. I found that i have no clamping problem if I put a 2" thick spacer between the work and the moveable jaw. So moving the clamping nut back by two inches puts me in pristine leadscrew territory. I'm guessing if I use this thing another 30 years, I may have to put in a 4" spacer at that point.

 

[Jason812]

Don't sell your bandsaws just yet ... I had the same problem with my 10x17 .. on mine there are two parts to the casting that goes around the ACME screw, the larger we'll consider the housing (214) and the smaller the offset-half-ACME nut (213) .. when my vise began to slip I considered worn out ACME threads on either the screw or the nut, but it turned out to be neither .. there is a roll-pin (215) going through the top of the housing which protrudes into the space where the nut lives, it engages with said nut when the vise handle is turned and pushes the half ACME thread onto the ACME screw .. if your vise doesn't clamp any longer, try tapping that pin down another 1/16 of an inch and try again .. as the pin wears on the casting, it'll have to be pushed further over the years .. one might be tempted to replace the wearing pin with a hardened piece of steel, but that woudl only result in the actual casting wearing down .. which is way more costly of a replacement than a simple roll pin .. hope this helps, fixed my vise issue for good ... cheers

View attachment 328216

This past weekend I picked up a barely, if at all, used G0651 and the vise wouldn't tighten. The pin (215) wasn't a roll pin but a solid pin with a poor attempt at knurling to keep in in place. I could drive it down slightly and get the vise to tighten but then it would push back to the top and the vise would slip. I simply made a slightly larger diameter pin and so far it is working just fine. I should have thought about it a little more and just put a roll pin in there instead.

If that fails, I'll get a piece of left handed acme all thread and a solid nut and just lose the quick acting capability.

 

[Tool Guy]

@Jason812 I just fixed mine 15 minutes ago. What I noticed was that pin was installed upside down from the factory. The gnurled end was at the bottom basically not having any effect of keeping it in. I flipped it so gnurled side was on top, tapped it in with a punch and it works great now. I'm sure it may wear and need to be sunk in more in the future, but looks promising. If it continues to move I'll surely switch to a roll pin and try that.
I had called Grizzly and explained my problem. They told me they had zero reports about problems with the vise. Looking around, I can see why. We fix it ourselves. Thanks Drizzly.
Thanks to @Swissmat for the solution. I didn't even notice that pin.