Coupling shaft assembly problems

[msandefur]

Coupling shaft assembly problems

Unfortunately, I have the complete parts for two (or more) different styles of coupling shafts, so it makes the reassembly rather confusing. I also have some questions. This is for my 1930-style 131 inch truck. In order to understand my problem, and hopefully take a stab at my questions, you’ll have to get out your copy of the AA truck supplement written by Jim Schild.

1. On page 42, center of the page, right above the Dual Drive assembly is a cross section of a coupling shaft assembly that clearly has two roller bearings in it, in addition to the universal joints at both ends. Has anyone actually ever seen a coupling shaft like this?

2. On page 27, top right corner shows 5 parts to a coupling shaft assembly. I have these 5 parts, but when I assemble them, the housing does not begin to cover the rear u-joint, and the housing stops about an inch short of mounting to the aft cross-member, as if it were missing another housing, or casting , or something. The photo on the bottom right shows an AA-7085-B rear bearing retainer. Am I missing this part?

3. Same picture, are these parts laid out in the correct order? Does the larger flat-faced U-joint go forward, and get covered by the larger bell-housing? Then the long housing and casting are supposed to cover the smaller U-joint on the aft end? Not only does the big end of the long housing not fit over the smaller U-joint, but the casting has threaded holes, which seem to attach to the transmission, not the cross-member.

4. On page 27, top left corner, there is a picture of this coupling shaft installed. Why is the U-joint hanging out on the aft side of the cross-member? My coupling shaft puts the U-joint on the forward side of the cross-member, and the hole in the cross-member is not large enough for the whole U-joint to pass through it. My driveshaft also makes the U-joint have to be on the forward side of the cross-member. What’s wrong here?

5. I also have another style cross-shaft, one that is similar to the one pictured on page 26, top left photo, except that it is for my 131 inch, not the 157. It only uses the one U-joint on the aft end. What kinds of housings, and in what assembly order are used with this shaft?

6. I’ve installed this single U-joint cross-shaft, but the housings don’t fit over the rear U-Joint. Unfortunately, there are no photos of this end in the book. Does anyone have a photo of this style coupling shaft installed in their truck?

Help!

[Neil Wilson]

msandefur,

There were three different coupling shaft assembly styles used for the AA trucks. Parts from each style can not be mixed with another style!


Style #1 (see picture below)

AA Coupling Shaft Assembly AA-4802 (1928 through mid 1929) - Used with the three speed transmission and the 131-1/2” wheel base chassis.

This coupling shaft has a stock A-7090 u-joint at the front and the AA-7090 u-joint at the rear. It has roller bearings at the front and rear ends of the AA-4804 housing. AA-4808 coupling shaft housing or dual high rear support is inserted from the back side of the #4 cross member.

The rear axle must be moved back to allow removal and insertion of this coupling shaft.

Style #2 (see picture below of shaft to transmission parts)

AA Coupling Shaft AA-4802-B (late 1929 through February 1932 - end of AA production) – Used with the four speed transmission and the 131-1/2” wheel base chassis.

AA Coupling Shaft AA-4802-C (May 1930 through February 1932 – end of AA production) – Used with the four speed transmission and the 157” wheel base chassis.

This coupling shaft has a female gear on the front and an AA-7090-B u-joint at the rear. AA-4808-B coupling shaft housing rear support is inserted from the back side of the #4 cross member.

The rear axle must be moved back to allow removal and insertion of this coupling shaft.

Style #3 (see picture below from Ford Service Bulletin)

AA Coupling Shaft AA-xxxx (Service replacement around July 1932) – Used with the four speed transmission and the 131-1/2” wheel base chassis.

AA Coupling Shaft AA-yyyy (Service replacement around July 1932) – Used with the four speed transmission and the 157” wheel base chassis.

This coupling shaft has a bolt together AA-7088 u-joint at the front and an AA-7090-B u-joint at the rear. AA-aaaa coupling shaft housing rear support is inserted from the front side of the #4 cross member. It is shorter than the prior AA-4808-B part and has the top bolt hole missing. The four speed transmission requires an AA-7085-B rear bearing retainer to allow connection of the AA-bbbb coupling shaft housing front support.


The coupling shaft can be removed without moving the rear axle back.

[msandefur]

Thanks, Neil. Wow, what great, clear and useful information. Now I see where I've been mixing things up!

One thing, though. Could you please post a larger picture of Service Bulletin page 35x? I can't quite make out all the parts.

[Neil Wilson]

msandefur,
I think the size limit is a problem posting a larger picture. Send me an e-mail and I will attach the pictures back to you. You can then enlarge them to be more readable.