Technical Model A rear axle problem

Hi,

I'm fairly new to the forum (on it a lot but don't post much!) I don't know if you can help but I've hit a real head scratcher (for me). I've been rebuilding the rear axle for my Model A traditional Hotrod using Tom Endy's guide. Got the pre-loads set for diff, got the pre load set for the drive shaft, went to assemble ready to set the backlash and before I've even tightened the bolts for the axle housing the drive shaft wont turn. To my uneducated eye it looks as though the pinion gear is to far towards the centre of the banjo (if that makes sense).
Appreciate I've probably done something stupid - any ideas what?
The bearing nearest the pinion is fully seated, the drive shaft bearing race is also fully home, the pinion gear nut has been correctly torqued and lines up with the split pin hole.
Any advice or direction would be greatly appreciated.

 

When setting preload for pinion did you use inch pounds?

 

is it a new gear set or did you use your old ring & pinion?

 

Because the pinion is not offset (hypoid), the pinion is not sensitive to depth and are just installed with no adjustment. You must adjust the differential side bearings to get the proper clearance (backlash). As usual, it is different and strange. The clearance is set by using different thickness gaskets under the side bells. It is a hunt and peck deal. I strongly recommend putting all the bell bolts in as I tried the lazy way of only putting in four to a side. I had to start over.
Ideally you would get the total gasket thickness before installing the pinion. This is so you can feel the drag in the bearings. This total thickness is then split between the bells and added or subtracted to get the backlash. The total gasket pack thickness must remain the same.

 

I’ve done our A rear twice now first a a stocker then I installed a HRW hemisphere for slide in axles ,,I used new bearings ,our local A parts supplier had a “deluxe” gasket set for the second build these were more robust for swapping around,,the first build I made the carrier bearings a bit tight I thought,,so second time I had a better feel ,also I made a spacer to go between the pinion bearings so to strengthen slightly as I’m running a 3.0 Mercruiser engine ,,the assembly is Not hard but take your time ,lube you’re bearings ,as Andy said use all bolts as you go to simulate finished torque,,