bcritical

I have TRS drives on my 1984 Scarab with twin 454's that pull about 550 HP each. My question is what is the acceptable backlash for these drives at the prop. The STRB one has 5 degrees and the PORT 2.5 degrees.

I know that most are checked using the clamp tool with tab on it and dial indicator which I would gladly do once I know what that spec is. I found the lower unit spec and upper unit spec but not the combined spec that would include the coupler. I have both units off to change the bellows since one ripped. While off I pulled the lower unit of the STRB drive and the backlash between the prop shaft and the input to lower unit is unnoticeable by feel same when check between the coupling and the u-joint for the upper unit. When I put them together I get the 5 degrees between the Prop and the u-joint. I just want to know what is acceptable and where I can find that spec. Maybe I am good.

Also does anyone know the distance between the center and where the dial indicator measures on that tool. Then I could give accurate measurements that you are all accustomed too.

Thanks,