@David K. Simpson posted:I thought about the timing of the rods but kind of dismissed it as it is absolutely smooth in reverse. Reverse is where the front gearbox is pushing down on its nose and the driveshaft is straightest. In reverse, the nose lifts and the angle of the shaft may be too much making it bind but I'm not sure yet. The gearbox is tight (I opened it to lube it), so i think my first step will be shimming the nose to reduce the amount the nose can rise. Could simply be manufacturing tolerances in the 'floating' gearbox on the front.
I don't think it's likely that the drivers are out of quarter, but I will say that you can see problems in one direction if they are. I have a JLC Allegheny, I see no issues in either direction, so it's certainly not universal.
My suspicion would be looking at the driveshaft dogbone, those are sometimes an issue.
