A local business in Chattanooga wanted me to bring my ‘52 F-7 Fire Engine to their parking lot during the running of the Chattanooga Ironman race. But my fire engine had other plans. I got about 3 blocks from the shop and I heard a loud sqealing noise, then a loud pop, and then I lost all traction. The truck was in gear, the driveshaft was turning, but I had no motive force. I had to call a tow truck to get pulled back to the shop.



The rear wheel bearing failed, the retaining nut and locking nut backed off. The axle and spindle dislodged from the differential.




I got it disassembled








The brakes weren’t damaged which is good since drums aren’t available and the shoes can only be fixed by being refined.




The outer bearing race would not come off. I had to cut it. I’ll just say here before someone else does, the truck is up on wood cribbing. The jack is just there as a safety.




when the bearing failed, the rollers destroyed the axle nut treads. I was about sick when I saw this. This suddenly became a much bigger project



I got on line searching for “floating axle thread repair”. I found a gentleman named Rodger Garrett in Cookville, TN who owns Axle Repair MD. He emailed me and asked for a few dimensions and told me he could fix this. He drove down to Chattanooga. He cut off the damaged section of the axle tube with the damaged threads and welded on a new threaded spool piece. It took less than 3 hours and half that time was inside the shop waiting on a thunderstorm to pass





I knocked out the old inner and outer bearing cups. I don’t own a press and I didn’t really want to load a 100+ lb or pay someone to do it. However, Publix sells dry ice for $2/lb. At -109 deg F, the new cups all but dropped in with just a few taps using a block of wood and a rubber hammer.






inner and outer bearing cups installed.




The brake drum and spindle have to be bolted together. They easily weigh over 150 lbs. I used an engine hoist to lift and level them and slide them onto the axle tube.
I hand packed the both the inner bearing (before installing the spindle) and the outer bearing.




Install the outer bearing and the adjusting nut. The Ford manual says to tighten the nut until there is drag on the wheel and the loosen it 1/8th turn until it spins freely. Others say to torque the nut to 200 ft-lbs, then loosen it and retorque it to 50 ft-lbs. Then losen it to align the locking tab. I went with the latter method. Then install the lock washer and lock nut. I bent the lock tabs after I took the pic

Ray,

That PM is about to get performed in the next week or two. All of the other three wheels are getting disassembled, inspected, the bearings cleaned and hand packed with new grease, and put back together.

I drained all of the oil from the differential yesterday and refilled it with new 140 weight gear oil. When I drained it, it was about 1/2 to 3/4 inch below the fill plug when I stuck my finger in. That is low, but not too terrible. We’ve all seen worse. I filled it back right to the threads. I got to thinking about why the bearings were dry. This isn’t a service truck. It only gets run around every few months in parades and such at low speed and on nice flat level streets. Since it never sees higher speeds, no curves, no hills, etc., I think that is hard on it. The differential oil never gets to splash and slosh around making its way down the tube to the wheel bearings, like it would if it were an actual service engine.

Oh well. Just a theory, but they will all get repacked very soon.

Keith