early 28 worm drive

AA Ford Discussion Group relating to the repair and restoration of your AA Ford.
birdacre
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Body Type: AA express
Model Year: 1928

Re: early 28 worm drive

Post by birdacre »

thank you for great photos. my bearing is similar. it however has to cage to set balls in. they just roll free, with the 2/3 diameter ball width void. i will try to get a photo tonight. just want to be absolutely sure something is not missing in my bearing. thank you, kevin
birdacre
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Body Type: AA express
Model Year: 1928

Re: early 28 worm drive

Post by birdacre »

i meant to say my bearing has NO cage to set balls in. sorry
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Neil Wilson
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Worm Thrust Bearing

Post by Neil Wilson »

Attached are the following worm gear thrust bearing photos:

1. AA-4696-A2 10 ball Gurney - a thrust bearing assembly with the balls enclosed between outer/inner races as a permanent assembly
2. Design 1 thrust bearing (three parts) - (2)AA-4697 and AA-4698
3. Thrust Bearing Hardware - AA-4695 retainer and A-21941 nut (used with either thrust bearing designs)

I am sure that these designs can be used for any worm drive axle.
Attachments
worm-thrust-2x.jpg
worm-thrust-2x.jpg (69.88 KiB) Viewed 6118 times
worm-thrust-1ax.jpg
worm-thrust-1ax.jpg (104.99 KiB) Viewed 6160 times
worm-thrust-hardwarex.jpg
worm-thrust-hardwarex.jpg (53.42 KiB) Viewed 6160 times
Last edited by Neil Wilson on March 17th, 2016, 9:13 am, edited 2 times in total.
Regards, Neil Wilson
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birdacre
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Re: early 28 worm drive

Post by birdacre »

HERE IS MY PHOTO. HOPE IT EXPLAINS WHAT I HAVE: IT LOOKS DIFFERENT THAN ANY OTHER I HAVE SEEN HERE. IDEAS, OBSERVATIONS, CONCLUSIONS WELCOMED. THANK YOU, KEVIN
I SEEM TO NOW HAVE NO PHOTO. IT SAYS IT IS TOO LARGE. MY WIFE TOOK IT ON HER CELL PHONE. ANY ADVICE, I FEEL LIKE A PILGRIM TO THIS TECHNICAL KNOW HOW. THANK YOU.
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macswoods
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Re: early 28 worm drive

Post by macswoods »

try going to edit. and resize the photo, and try until it is accepted.
birdacre
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Re: early 28 worm drive

Post by birdacre »

0314161817b (640x360).jpg
0314161817b (640x360).jpg (183.3 KiB) Viewed 6184 times
Here is the picture. Hope it shows exactly what I have.
Thanks in advance. Kevin
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Neil Wilson
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Re: early 28 worm drive

Post by Neil Wilson »

Kevin,
How is the bearing in your picture different from the AA-4696-A2 photo?
Regards, Neil Wilson
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birdacre
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Re: early 28 worm drive

Post by birdacre »

the balls in my bearing have no spacer. yours are evenly spaced. is there not a spacer in yours. you can see the void in my race. as they turn it varies which balls have the space, quite a space too, about 2/3 the diameter of a ball, as if one was missing, but not possible, because the space is 1/3 too small. hope all is well. kevin
birdacre
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Re: early 28 worm drive

Post by birdacre »

i did some research and there seems to be a ball bearing that is "self centering and without a cage" it is built with deep grooves for the balls to roll in. now. just curious if anyone has a photo similar to mine. neil, your photo looks like i am looking at the cage and not the actual faces of the balls. is this true? photos can be confusing to me. thanks again. kevin
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Neil Wilson
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Re: early 28 worm drive

Post by Neil Wilson »

birdacre wrote:i did some research and there seems to be a ball bearing that is "self centering and without a cage" it is built with deep grooves for the balls to roll in. now. just curious if anyone has a photo similar to mine. neil, your photo looks like i am looking at the cage and not the actual faces of the balls. is this true? photos can be confusing to me. thanks again. kevin
Kevin,
What is the source of your research (Ford engineering drawings or otherwise)? Do you know what month/year AA that your rear axle is from?

The MAFFI database shows there was an AA-4696 with no suffix, and AA-4696-A2, and AA-4696-A3. I am fairly sure that AA-4696 with no suffix is the 1st design made up of three separate parts. Engineering drawings would need to be ordered to see the difference between the A2 and A3 part.

After some Internet searching, I think the proper way to describe the AA-4696-A2 or A3 bearing is - "a thrust bearing assembly with the balls enclosed between outer/inner races as a permanent assembly". And, I will attempt to correct my prior post accordingly.
Regards, Neil Wilson
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birdacre
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Body Type: AA express
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Re: early 28 worm drive

Post by birdacre »

hey neil, kevin here. i just generically researched different bearing designs and found the cage less self centering type. it would be neat to see if someone has the same. my truck is dec 28. i assume the axle is original. was i correct in thinking that your photo showed the cages and not the actual bearing face. it can be an optical illusion unless seen first hand. thanks for all your thoughts. kevin
KimVanOrder
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Re: early 28 worm drive

Post by KimVanOrder »

I have 28 Dec. also. With the same bearing. We call that type a roller thrust.
KVO
Dec. '28 AA
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Neil Wilson
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Re: early 28 worm drive

Post by Neil Wilson »

birdacre wrote:hey neil, kevin here. i just generically researched different bearing designs and found the cage less self centering type. it would be neat to see if someone has the same. my truck is dec 28. i assume the axle is original. was i correct in thinking that your photo showed the cages and not the actual bearing face. it can be an optical illusion unless seen first hand. thanks for all your thoughts. kevin
Yes, the AA-4696-A2 or A3 bearing has the balls caged. I looked at the other one I have and it is the same design. I don't know what month/year these worms came out of.

I took the rear axle housing cap of a May 1928 axle and found it has the design 1 three part bearing - see attached.
Attachments
worm-thrust-5-28x.jpg
worm-thrust-5-28x.jpg (267.43 KiB) Viewed 6149 times
Regards, Neil Wilson
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birdacre
Posts: 480
Joined: October 8th, 2013, 2:37 pm
Body Type: AA express
Model Year: 1928

Re: early 28 worm drive

Post by birdacre »

hey kim, thank you for the info. so in december of 28 there must have been a surplus of these bearings. does your bearing have the exact same void? about 2/3 the diameter of a ball? do you have a photo just out of curiosity? it would be neat to see two rare oddities in the same story. thank you, kevin
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tiredtruckrestorer
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Re: early 28 worm drive

Post by tiredtruckrestorer »

According to the Indianapolis Service Letters, there seemed to be a lot of trouble with the worm drive thrust bearings. In October 5, 1928 letter it mentions the changeover from the TT style worm thrust bearing, retainer, and collar (part numbers TT-114 and TT-123) as used on the "TT" trucks to the new AA-4696A2. In a April 10, 1929 letter, it states the AA-4696A2 Gurney thrust bearing has been redesigned. The retainer was made heavier and has a wider surface that rests against the thrust cap. The trust cap has also been hardened to keep the bearing from cutting a groove in the cap. In May 14, 1929 all trucks were being assembled with the hardened steel plate with a Zerk fitting. A July 24, 1929 Service Letter said that the new 10 ball Federal bearing can be used interchangeable with the 9 ball Gurney in replacement of the old 10 ball Gurney that was giving trouble in service. In a August 8, 1929 Service Letter Ford instructed dealers to return their stock of 10 ball Gurney bearings for credit and restock the new 9 ball Gurney and 10 ball Federal, which were all carried under the same AA-4696-A2 part numbers.

This may help explain why there are several different styles of thrust bearings and which ones to look out for. Note that after the changeover from the "TT" style to the "AA" style they all carried the same Ford part number.

Keith
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