1940 Rearend Help Needed

I really could use some help if anyone might have a suggestion to what is wrong.
I bought a very good 40 rearend awhile back, complete drum to drum. It already had the brakes replaced, axle nuts torqued down and everything worked great.
I picked up a old culver city halibrand quick change, and had a shop that works on those install the quick change into my 40 rearend.
I installrd the rearend on my coupe, put the drums on and torqued the axle nuts to 150lbs, and it locks up the rearend.
I have taken it apart many times, looks fine to me. It has the same axles and parts that worked before, the quickchange is the exact same width as the old 40 pumpkin that was on it. I have tried marking with a paint pen on the lip of the backing plate, and anywhere else that it might touch and not seeing anything. I also tried it without the brake shoes in case the brake shoes were too wide, and it also locks up without the brake shoes.
Any suggestions would help, Thanks!

 

Call the shop that installed the QC. Maybe to get the gear mesh correct, they spaced the ring to one side more than before. Is a drum binding against a backing plate down in the groove?

 

Ok, will do. I have painted the backing plate groove, it dosent look like its binding there

 

I presume the axles turn fine with the drums off therefore the drums are locking up the rear end. Is that correct? If so loosen the drums until the axles turn and see how much thread you have on the axle. Sometimes the keys get stuck or allow the drum to go on too far. If that all checks out the center section is not installed correctly as Alchemy states above. You could also try adding another gasket to move the housing out a little more.

I use Speedway Engineering in Sylmar to solve my problems. They are very knowledgeable.

 

Make sure you have the correct gaskets installed between the axle tubes and the center section. The gasket thickness is what controls the backlash on the gears.

 

Thanks guys. Yes the axles turn fine without the drums on. I am looking and do not see any gasket between the center section and the tubes.Looks like thats the problem, they put a film of gasket maker insted of a gasket.

 

The gasket(s) is very thin, but if it's not really there, that is a problem.

 

if a key slips it usually ends up keeping the tapered hub from seating on the taper of the axle. The hub can't go on too far on the axle due to it having to seat on the taper of the axle. Backing the nut off may free the thing up but will not cure the problem. There is another problem here and most likely it has to do with the assembly procedure having a missed step.

 

Slammed: You know there's something to the gaskets when they are offered in different thicknessess......Tim

 

Axle shims. I needed to use them to space the drum out a bit from the backing plate.
Macs has them if it turns out you need them.
Just a maybe....

 

Will my 36 Ford axle tubes and axles work with a newer model quickchange center?

 

what do you mean by newer?