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Does any one have any pics of a 1928 Worm drive rear, I am trying to see if the are any visual cues that would help differentiate between the production years. As always, thanks in advance.
Jared

Below are pics of my August of 29 rear

Top

Rear

Backing Plate

Brake Drum

Hello Jared,
The only two things I can think of, make sure it has the emergency brakes and look for a B stamped on the left side of the differential housing; this means it has the high speed ratio.

Brian,
Thank you for the feedback on the casting mark and emergency brake . That should definatly tell me what I need to know. What I saw that was throwing me off was backing plates on both sides of a rear end that had the two dust gaurd halves on each side not there . By dust gaurds I mean the two additional peices that are riveted on each end and spot welded to the outside of the backing plate to keep dirt, dust, etc... from getting in the drum. Have you ever seen anything like that before?
Best Regards,
Jared

The first backing plate for the axle with emergency brake bands did not have the dust rings. The dust rings were add sometime in '29 (late '29 per the Judging Standards). This backing plate was used until mid '31 when the dust ring was part of the backing plate stamping. See E-12 of the Judging Standards for pictures.

Neil,
Thanks for your input it is much appreciated. From reading your response I gather that I can uses any rear backing plate from late 29 AA to mid 31 AA on my truck, am I correct?
Best Regards,
Jared

The left housing in the worm area has an enlargement the inside of which is an angled gutter which feeds oil to the bearing at the end of the worm. This feature is NOT on the early worm housings. This change was a "running change". The early worm rear end has left and right housings of the same type. The right housing of the early worm rear end has a square with some letters and numbers upside down. It might read TT75. This was deleted in the later rear end. There are some changes in the worm cap which are documented in the Service Bulletins. Oil goes in the worm cap plug hole, not grease even though the factory for a while used a grease fitting on that cap.

Jared,
Yes, the backing plate is the same from late '29 to mid '31 and be original. the early '29 and late '31 backing plates are interchangable with the late '29 to mid '31 if you are just wanting something that works.

Ed,
That is the first time I have heard an explaination of why the "bulge" in the worm axle housing. Thanks!

Neil,
Thank you for the confirmation on the backing plate.

Ed,
Thank you for the housing information. I assume that the TT75 was most likely from a carry over from being used on a TT truck.

Best Regards,
Jared

this is the worm drive on a TT truck im looking at any info you can share would be great

This is not much - but - a friend of mine had a TT with a ruxtal (spelling?) rear axle that allowed the axle gear ratio to change. I think that the TT could have had either an under or over drive axle.

I bet that a post on the T forum of www.Fordbarn.com will yield information.

how does the rear spring come undone from axle. looks like a large slotted screw. there is also a side locking bolt. any ideas anyone?

Remove locking bolt and drive out slotted shaft - probably worn and bushing thats supposed to be in the leaf eye will come with it as they are typically very worn. Be sure the leaf eye didn't wear into the clamshell. Should slide out either way. Slot is there so you can rotate the pin to align the new lock pin upon reassembly. Soak in your favorite penetrating oil for a few days.

If your just tryign to remove the axle its easier to remove the 4 bolts holding the clamshell that goes around the axle off first.

thank you for the info. i didn't realize that the clam shell came off so easy. are there seals that go with it. another question..... I have a four speed in my 28. it was switched years ago. I took it apart and made 1 good transmission from 3. all gears and clusters in VG shape. it has developed a railing noise in 4th. not the typical whine but a railing noise. both input and output shaft bearings were new. I wonder if mix and match gears start to sing after a bit. have about 200 miles on truck since reassemble.any ideas appreciated thank you, kevin

Make sure you roil level is still where it needs to be. And yes mismatched gears can make noises.

The clamshells i refer to re the ones that go from spring to rear axle. No seals - should be greasy though. Clams are typically worn thru because of noone ever greases anything. Should have well defined grease grooves in both pieces.

i think i will just drive it. it runs nice. hey what is your thought on the mitchell overdrive. i put up a post and one guy just installed it and loves it. have you ever seen one.