I have been thinking about my approach to tighten the axle housing to the saddles. Because the weight and wear and tear directly affect the upper half of the saddles - it is no wonder these wear down and cause a loose rear axle in spite of new springs and shackles.
The original saddles had a 5/32" gap that was excessive. Fortunately I had 2 other sets to compare the wear and the gap between the upper saddle and the axle housing. I found a set that reduced the gap to 1/16".
Although grinding the saddle halves to fit is a good option, my preference was to build up the inner area of the top saddle to replace what had been ground down from 75 years of use, dirt and rust action.
My first step was to fill the rust pits on the axle housing. I used a paste (LabMetal) that has aluminum powder in it. I let it cure overnight, a
filed, and sanded the axle housing smooth.
My solution was to use a two part slow curing epoxy paste called PC7. Similar to JB Weld, this mix is thicker and won't run or sag. I spread the mix on to the casting of the upper saddle. I then cut 1-3/16" x 4" long brass shim sheet strips and glued them using the PC7 as the binder on the inner saddle. I used two layers of this brass shim sheet by epoxying another layer of the this material next to the first set to make up for the gap. I placed a sheet of plastic wrap over the axle housing and pressed the two saddle halves together. The second layer of brass would sit next to the axle housing. The plastic wrap would allow for any PC7 to squeeze out and laminate the brass shim to the inner saddle but not allow it to bond to the axle housing. I screwed the two halves together and let sit to allow this brass sandwich to form to the out of round saddle and axle housing.
I removed the saddles and cleaned the squeeze out in the grease channels and reassembled onto the housing. Once hardened I will remove the plastic, grease the mating halves, and reassemble to the housing once again.
I have used this epoxy in other applications and after it cures (takes about 1.5 days depending on temperature but another week or more to fully harden) it's tough and hard as nails. Sandwiching the brass with the epoxy is a gamble - but this is a truck that will be out to pasture and will not be used as a work truck.
I will be curious to see how this works over time. I took pictures if anyone would like to see.
Last edited by tom moore; 11/22/2016 7:47 PM.
