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Posted

This any good?

(Sorry, don't know what a "BB truck" is :()

I have saved that frame plan, it is for a 32 car chassis.

A BB truck is the 1.1/2 and 2 ton version and has a different chassis.

Posted (edited)

Would anyone have a diagram or detail pics of a Ford BB truck chassis.

The '32-'37 Ford BB truck is, of course, a 1.5 ton rated truck (considered "heavy duty" by Ford, Chevrolet/GMC, Dodge, Studebaker in the early 30's). It's a "ladder style" frame, having straight crossmembers unlike Ford 1932-48 passenger cars, which used at first a K-Member at the transmission mounting (1932) and then an X-member thereafter for torsional stiffness.

The BB frame is almost identical to the 1930-31 AA truck frame, differing only in the thickness of the steel used, and having a 1" or so deeper side rail design. This is a '31 Model AA truck chassis: 31aa_frame.jpg

The AA chassis pictured is virtually the same as the BB as I noted above, with the exception of the rear suspension layout: The AA truck chassis pictured has parallel leaf springs at the rear, with the semi-elliptic springs mounted "upside down", bolted in their center to the side of the frame rail, the front of the spring shackled to the frame, the rear end of the spring shackled to the top of the rear axle, cantilever-style. This was an inherent weakness in the design, when one considers that for practical purposes, nearly all the weight of cargo was carried by the rear axle (55% forward, 45% rearward of the rear axle centerline), making the breaking of a rear spring an all-too-frequent problem. For the BB, the rear leaf springs were reversed, mounted in the same manner as they would be on a passenger car, the ends of the main spring leaf shackled to the chassis, the center of the spring bolted solidly to the top of the rear axle--which is standard practice to this day on heavy truck leaf springs.

The front axle is the same design as Ford passenger cars, but was a steel forging (as were Ford "beam" front axles through 1948), but was about 25% heavier than the passenger car axle (you can use a passenger car axle on the model, most model kit Ford front axles are molded neavier than scale for strength). The front spring is transverse, just as on the AA truck chassis pictured, but was made of wider, thicker spring leaves, and had 4-more leaves in it than on the passenger car. The mechanical brake drums are much heavier as well, with cooling ribs around their circumference.

The rear axle was much larger than the passenger car unit, and was a full-floating design (meaning that the axle housings carried the full weight and forces exerted of the axle shafts and the differential gear system (Ford passenger car rear axles from 1928-48 were 3/4 floating, the axle housing carrying the weight of the vehicle, but the axle shafts carrying the differential gearing). To find what this axle looked like, research Ford 1.5 ton trucks from 1930-52--they are ALL the same design, differing only in the part number, which changed yearly!

As for engines: Model AA of course, used the same 200.5cid 40-hp flathead 4cyl as the passenger cars, with a 4-speed top loader manual transmission. 1932 Ford BB trucks used the Model B 4-cyl engine (an upgrade of the Model A engine, virtually identical in appearance, with only the oil overflow pipe on the left side valve galley cover plate being deleted, and of course, an AC mechanical fuel pump added to the right side front of the cylinder block. V8 engines were in very short xupply through most of the 9-month production run of 1932 vehicles from Ford, which lead to them being excluded form heavy duty truck use--beginning with the 1933 model year, however, V8's became available for heavy truck use, and by early 1934, the Model B 4-banger was discontinued for lack of demand for them.

BB trucks, as with the AA, were offered in two wheelbases: 131" and 157".

Hope this helps a bit!

Art

Edited by Art Anderson

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