Hi guys......my first post and I think I've found a work around for this issue.
I started suffering the same issue over this weekend using my VTR and a pro tank II. The ohms all over the place and the tank just wobbled and would never properly screw in. I put my I clear 30s back in the VTR and it worked perfectly so I got to thinking that maybe the length/diameter of the protank thread might just be on the edge for the VTR. So.....here's what I did...
1) Went through all my "spares" box and found a 510 / EGO adaptor (the type you would use if your carto has a skirt)
2) Again, in my spares box, took the protank vanity ring (you'd use this if you were putting a tank onto a standard ego battery)
3) Lightly screwed the 510 adaptor and vanity ring into the base of the VTR.
4) Then screwed the protank into the top of the adaptor / vanity ring and screwed until finger tight.
For me....this works like a charm, stable ohms and tank no longer loose.
Obviously the tank is a slightly more raised than before, but it doesn't look odd and still ends up being about the same height as the Iclear 30s
Love the VTR.....love the protank......gutted when this problem happened but had my VTR for a while now and was not convinced I'd get a replacement.
Hope this work around helps for anyone who still struggle to get a replacement VTR and wants to stick with a protank and VW.
Cheers.....