Dizzy1 ,,, Were you using the old aluminum diff half's, delrin or plastic. ???? I will look again at the two screws in the morning just to be sure. But 8mm??? thats a big difference.
I used the Cyclone D4 2.6 screws, I used that one with no spacers/shims all last summer with the old aluminum diff half's. At first I re-taped the stock T-nut to fit the 2.6 screw, I later found the right T-nut at RCMARKET and everything worked great.
I'm using the 44mm steel axles, this summer I tried the new POM pro spec and it only works in the back, it's to long for the front. (Maybe that is something like the problem you had???)
So the aluminum pro spec works fine in the front or the back in my Cyclone but the POM only works in the back.
There are lots of people using the HB 2.6 screw in the old diff without any problems.
If you look back about 30 or 40 pages you will find the discussion on the 2.6 screw in the old diff.
Last edited by Lazer Guy; 09-15-2008 at 05:43 PM.