Allis Chalmers Model B Engine Side Weights There are two bushings, called "spacers" (AC part #213409) that are used to mount the right and left hand engine side weights on the tractor. They mount to the front support plate with 5/8 -11UNC x 2-3/4 long hex head bolts with matching hex nuts and lockwashers per the AC parts book, but I'm using 1/2-13UNC x 2-1/4 long ones as shown here: And here's what the weights look like on the tractor (left side): The support bushings for these weights sometimes get lost over the years. Even if you are lucky enough to purchase some original side weights, the bushings may not be with them. They are easy enough to make though. For those who would like to make their own, I have prepared a detailed dimensioned drawing for the original bushings, available in pdf format here. You will notice that the left side weight has a chamfer at an angle along the lower side. That is for clearance with the B steering linkage. The right side weight doesn't have that chamfer. I have had people suggest to me that I don't know my own weights that I have been using for many years - that both weights are exactly the same and both have that chamfer. They are wrong, as you can see here: Furthermore, a careful look at the following original picture of a wartime B will show that the right side weight does not have a chamfer - it is the same as mine: I realize that the later AC parts books show weights without distinction to hand and a quantity of two. Also that knock-off weights both have the chamfer. Furthermore, other weights I have noticed on Bs are, in fact, the same - with the right side weight having the chamfer on the top when installed. But it wasn't always that way. I can assure anyone that the weights I have are the original weights that came with my 1942 B. The tractor and the weights have been in the family since they were new. It may have been that AC concluded at some later point that it was not economic to cast two different weights when a single casting would work just fine. In any event, the above pictures are evidence that the early AC engine side weights for the B were two different castings, one for the left and one for the right.  Rod (NH) March 2006 Home