To lessen any possibility of the “AA” differential gear case screws imbedding them- selves in the malleable iron gear case, the screw has been redesigned to produce a larger head area (see Fig. 1176). The new screw (AA-4216) replaces the A-21168 screw for both production and service on all AA-4000-K and L truck axles.
To increase the strength of the A-21168 differential case screw, the diameter of the body has been changed from .w85/390 to .433/.438 and the hex. Head from 5/8” to 11/16”.
A new design power take-off assembly AA- 7251-B has recently been released. This assembly complete with all necessary parts for attaching (with exception of lever AA- 7270-B) is supplied in carton under part AA-7275 at a list price of $12.50. The price of the lever is $1.00. These prices are subject to dealers’ regular parts …
The driving pinion bearing shims, which are used to regulate the adjustment between the ring gear and pinion in the new truck bevel gear axle, are furnished in the following thicknesses:
TRUCK RING GEAR AND DIFFERENTIAL CASE LISTED UNDER PART AA-4207 As stated in the January issue of the Service Bulletin, the driving gear in the new truck bevel axle is riveted to the left half of the differential case and will be sold through service as a single unit. Part number AA-4207 is the number …
TRUCK RING GEAR AND DIFFERENTIAL CASE LISTED UNDER PART AA-4207 Read More »
The new spiral bevel gear rear axle for the Model AA truck is now available in two ratios -the original ratio 6.6 to 1 for heavy duty hauling and a new high speed ratio of 5.14 to 1 for lighter loads where speedy delivery is the chief requisite. Equipped with the new high speed gears, …
Occasionally a complaint was received of differential pinions freezing on the differential spider and damaging the axle parts. To lessen any further complaints of this kind, pinions are now provided with three 1/8” oil holes equally spaced around the teeth (see FIG. 820). This assures these parts receive ample lubrication.
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