40 banjo mixed up parts ...HELP

Init1

Init1

Senior Member
Getting frustrated. I have a 40 banjo that came out of a driving car.
I rebuilt it even with marginal axle threads but now have decided to replace the axles with better ones. The passenger side also has about 1/8" end play that wasn't there before I took it apart. The drivers side is ok.
Soooo, I picked up some replacement axles and a nice complete diff with spiders. All supposedly 40 Ford.
Went to test assemble the axles in the diff and the gears don't appear to mesh
Properly.
Spiders are 11 tooth and the axles are 18 tooth.
The axles measure 31 15/16".

What the heck do I have and what do 40 banjos have for spiders and axles? And what is causing the end play?
Any and all help greatly appreciated.
 
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There were both 16 and 18 tooth axles, either set will work in your differential, but must be mated with their spider gear. Your axle length is a mystery to me, however. Below is an article from Street Rodder magazine that can help identify what you have.

http://www.flatheadv8.org/fordrear.htm
 
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I'd do a lot of measuring. It's possible you don't have what you were told you have - i.e. not a '40 rear end or not all '40 parts.
 
Init1 said:
Getting frustrated. I have a 40 banjo that came out of a driving car.
I rebuilt it even with marginal axle threads but now have decided to replace the axles with better ones. The passenger side also has about 1/8" end play that wasn't there before I took it apart. The drivers side is ok.
Soooo, I picked up some replacement axles and a nice complete diff with spiders. All supposedly 40 Ford.
Went to test assemble the axles in the diff and the gears don't appear to mesh
Properly.
Spiders are 11 tooth and the axles are 18 tooth.
The axles measure 31 15/16".

What the heck do I have and what do 40 banjos have for spiders and axles? And what is causing the end play?
Any and all help greatly appreciated.
Click to expand...

Can you post some pictures of the parts and pieces you are trying to assemble? Do you have access to the internet articles that give instructions on how to put a Ford banjo rear together?
 
1935-41 passenger axles are the same length, 32.85", but 1935-38 axles have 18 teeth whereas 1939-41 axles have 16 teeth. So, you can use either 16 or 18 tooth axles in any 1935-41 passenger rearend, but you must use the 12 tooth pinion gear with the 18 tooth axle shaft and the 11 tooth pinion gear with the 16 tooth axle shaft.

The shortest axle shaft with 18 teeth that I see in the chassis parts catalog for 1928-48 is 32.18", which is for 1932-34 V8s. Are you measuring the axle in overall length, tip to tip?
 
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As with most flathead stuff, the 1938 rear axle was a transition year and you can not be sure of what you have (axle tooth count) without checking. But as a practical matter this applies to almost any year because to the age of the vehicles who knows what has be changed over the years!
 
Guys...
Carefully remeasuring with the lights on my axles are 32.85" and have 18 teeth.
I need a set is 12 tooth spiders.
 
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