Does anyone know what the back lash should be on the on the prop flange. I have .011".
When I rock the prop shaft back and forwards there is quite a clonk just like a nackerd diff.
From my old MK2 Cortina days I'm sure pinion to crown wheel used to be .003-.004", which translates to an awful lot less than .011" at the input flange.
I have also just about managed to flush all the black goo out with lots of diesel and patience, not a quick job to say the least especially when I took the drain plug out and got most of it up my sleeve.
Now I plan to replace the egg cup full of tar with 450ml of Millers EP140 and hope it will run a little quieter.
Dab, when I read your .011" backlash I thought that sounded about right. I did some checking on the rear ends I used to setup, Ford 9" and GM 10 and 12 bolts. They all seem to be in the .008"-.014" range and when reviewing the smaller diameter ring gears, they did not drop in backlash specs. Racing gear sets tend to be set up a bit looser.
Now some others did have .006" to .010", but most were all in the low to mid teens.
I'm curious though how you measured your backlash. When I setup a 3rd member like a 9" Ford, I have my dial indicator mounted on the case and I physically have the tip on the ring gear tooth 90 degrees to the rotation so I have a good feel for the direct motion. If you're measuring the amount of rotation a driveshaft has before the sprocket moves, it not going to be a true backlash reading of the ring and pinion gears.
I'm not certain, but is the output shaft of the BB pressed into the ring gear or is it splined to the shaft? If it's splined you can also be picking up some "slop" in the spline. But it's not uncommon to get some twisting of the driveshaft before anything happens to the output sprocket.
