Rear end question repetitive I know

[1929 AA boy]

Ok so the AAs that I have running and driveing all have worm drive rear ends In them and that's fine and dandy but on my most recent build I'm going for more of a driving work horse than a garage queen now to the question ( I want the high speed)
In my parts trucks I have one bevel gear rear end it's a early 30 I just recently bought a 29 that I have yet to bring home and everything about it says it's a 29 but it has a bevel gear rear end then on another parts truck I have a worm drive that I can't find a single marking on .... I know I can rotate the drive shaft and see how long it takes for the wheel to turn but that requires disassembleing three trucks
Now on the bevel gear rear ends I can see markings but don't know what they mean there are no tags anywhere if some one could save me the time of taking them all apart that would be great ... I have searched on here and can't find too much info on the ring and pinion type rear ends

[spectria]

The markings might mislead, as sometimes the Ring and Pinion have been replaced:

diff%20stamp%20copy_rotation.jpg (68.25 KiB) Viewed 4538 times

736 = 5.14 which is the higher speed Ring and pinion axle

http://forums.aa-fords.com/viewtopic.ph ... tio#p19917

[SHELBY MESSER]

29 AA boy, If your trucks a altogether (engine tranny and rear end) You could jack up one rear wheel attach a rod-board to the rear tire or wheel sticking out for enaught to it from in front of truck. Next remove the sparks plugs. Then shift the tranny in high gear. Then with the hand crank the engine until the rear wheel rotates 1 revelation,You need to mark the starting point of the hand crank and count the revel. of the crank and at this same mark, you may have to retate the rear wheel 3 or 4 times and record your results on each truck. You should be able to find the high ratio rear axle. Hope this helps. Shelby, Louisiana.

[spectria]

As Shelby says, the rotation counting method is the only guarantee of which diff you have. If you are in high (3rd or 4th is 1:1 in respective trans) the difference in revs from crank to wheels gives you the ratio.

[Bob C]

You can unscrew the speedometer drive gear on the torque tube and the ratio should be stamped
on the gear, but there is no guarantee it is correct either.

Bob

[1crosscut]

On your worm drive with no markings you might be lucky and have one of the early rear ends as they all were high speed. It wasn't until later that they offered the low speed and started marking the axles with an A or B. On your worm drive is the speedometer gear housing on the front of the drive shaft tube cast into the shaft or is there a removeable pot metal cover for it held on with two screws?
Yes the only way to tell for sure is to rotate it and count the revolutions. On two of the trucks that I bought they were stamped as low speed but the gears had been changed to high speed.
Has anyone ever run across a rear end marked as high speed but has low speed gears in it?
Dave

[gunmetal 2]

Not me. The high speed rear end has 31 teeth on the gear and 6 on the spindle. This man makes for the AA as well.

[Stakebed]

expensive but probably well worth it and will last a lifetime. what i feel wore these out is these trucks being used as trucks and getting 1 2 even 5 tons moving takes alot of torque and force.

[spectria]

I think a lot of the damage is from moisture that gravitates to the high point in the gear case and corrodes the gears. Maybe a synthetic blend wouldn't drain away from the high spots.

[Stakebed]

I think a lot of the damage is from moisture that gravitates to the high point in the gear case and corrodes the gears. Maybe a synthetic blend wouldn't drain away from the high spots.

ahh yea that too, but at the same time that oil in em is mighty thick but yes lots of dry starts causes a buttload of wear lol

[spectria]

I think a lot of the damage is from moisture that gravitates to the high point in the gear case and corrodes the gears. Maybe a synthetic blend wouldn't drain away from the high spots.

ahh yea that too, but at the same time that oil in em is mighty thick but yes lots of dry starts causes a buttload of wear lol

I also meant to refer to the corrosion and pitting and just rusted bearings in that rear housing, moisture is sure to form there at the top, with little airflow. Seems a fellow posted a thread that had removed the rear housing and found the bearing rusted solid?