Pinion Depth Number

[66BlueGoose]

Getting ready to set up a new diff, looking to figure out the starting point for pinion depth. My old one was marked +1. Having a difficult time reading the number on this new USA Standard Gear set. What would you read this number as? 0?

 

[DirtDonk]

Now that looks familar!
Following along to see what details emerge.

Bottom numbers look like a couple of zeros from here. Or an Omega sign just to mess you up!

Good luck.

Paul

 

[66BlueGoose]

Yea has was torn between omega . 0 and 010. Got to believe its the first one.

 

[66BlueGoose]

Ok, have all the pieces back from plating and powder coating. Build day tomorrow. I did forgot one thing, to take a picture of the differential tag location, anyone know which diff stud it goes on? I think it was a top or side one?

 

[66BlueGoose]

Ok, first pattern, think I need to set pinion a bit deeper. Backlash at .009. First picture drive side, second picture coast side. Opinions?

 

[NC-Fordguy]

paint some more teeth around 120 degrees from the current position to get a more accurate read and post some pics of those up

 

[66BlueGoose]

same settings, 120 degrees out.

 

[pcf_mark]

I'm just following along.

FWIW when I used to set up GM rears (sorry!) we used to set the pinion depth with a bias toward the outside edge of the ring gear teeth. Not dead center but a few thousands toward the outside. The pinion would bend under heavy load (slicks, trans brake) and then be putting the load in the center of the ring gear teeth.

 

[66BlueGoose]

Started moving the pinion in, (removing shims) but seemed like it was going the wrong way. Went back to original then moved it out. Current pictures, back lash at 010-012.

 

[NC-Fordguy]

Are you creating a bit of drag by holding the pinion taught when checking run out? When I set up gears I'll grab the pinion tight and spin the carrier with the box end of a wrench via the ring gear bolts in a back and forth motion.

With the backlash you're reporting the pattern should leave a tighter impression. Also by my eye there's too much variance from tooth to tooth. I can't help but wonder if there is some debris keeping the ring gear from setting even on the carrier.

In the case you've done all of the above run it

 

[66BlueGoose]

I was creating drag during the check but was turning the pinion and putting drag on the ring gear. Tried your method and got a better imprint. Pictures below. I did check the ring gear for runout, only varies .001.

 

[goldstar]

when setting up rears, i use permatex prussian blue for the pattern. it seams to show better and will transfer to other teeth for a nice pattern. your blacklash looks good, but pcf mark is right should be towards outside edge; might add a small shim to pinion to get it a little deeper. imo