Has anyone rebuilt a precision instruments torque wrench ratchet head?

[Neoumlaut]

I've had my precision instruments split beam wrench for a few years now and it's never ratcheted, I was always under the impression it just had a fixed head. The other day I was looking at it and thought, "that sure looks like a ratchet head" and of course it is. I opened it up and there's nothing obviously wrong with it - it has the two ball bearings, and without the cover in place it seems to ratchet. When I put the cover back on it locks up.
Has anyone taken one of these apart before? Is there something I'm missing?

 

[Neoumlaut]

I took a few pictures in case anyone had seen a similar design - I've never seen a unidirectional ratchet before.

 

[Rabid Badger]

My first step would be to disassemble the head completely, clean everything thoroughly and check for any burrs. Take an extra close look at the cover plate and the anvil, make sure there isn't anything causing it to bind up against the housing.

If everything looks good reassemble with your favorite ratchet lube and see if it still has a problem.

Take an extra close look at the cover plate and the anvil. Make sure there isn't anything causing it to bind up against the housing.

 

[jimmyin3D]

Have you contacted PI and asked them for warranty help? Maybe it’s just bad fitment bad machining like you said it never worked right. I can take pictures of mine later if it’ll help.

 

[Neoumlaut]

Well I've fixed the problem although I'm not completely satisfied with it. It seemed like the jam was caused by the top ball bearing wedging against the top plate, so I just removed it, and now it works! It now ratchets like it should. My guess is the top ball bearing is too large (it's significantly larger than the lower one), and instead should be the same size as the lower one.
If anyone has one of these and wouldn't mind opening it up and comparing the size of the two ball bearings (or measuring them if you can) that would be awesome, but at least I have it functional for now.