20 years or so ago I lucked into a guy who was street rodding a 41 Studebaker. I bought all the parts he did not want including a spare engine, overdrive transmission, and a differential. I always meant to tear into the diff to see if the brake drums were any good but never did. But when I was looking at the parts book I noticed that it showed a cover to keep road debris out of the parking brake slot. That was missing from my car so I decided to see if the covers were on the backup diff. I had to dig the axle out of the shed and haul it around to the garage, but I will spare you that part of the saga.
I did not want to work on the floor so I figured out how to put the diff on the lift. The lift pads are under the spring perches and a 2×4 keeps the nose of the diff up. Two hefty c-clamps are holding the spring perches to the lift pads. There was maybe a pint of gear oil in the diff. No signs of water or metal in the oil.I assume this is September, 1941. Unless this thing has a really odd axle ratio. It is a diff for overdrive cars, which was different than the straight three-speed.Next I had to get the hubs and drums loose. Both sides did not want to turn, but after working the shoe adjustments for a while and prying on it I got them to move. After that it was just putting the hub puller on. Before I beat on it I lowered the axle onto jack stands. I am not sure I can hurt the lift with a hammer but why take the chance?This is about what I expected. The cylinder has visible corrosion poking out the ends and at some point both water and oil got in here. Yuck. Lets tear the brakes off.The axles have some rust as well. But this will clean up. The brake shoes are obviously toast but the metal is in good shape and these things have a lot of value as cores. In fact you can’t buy new shoes for this car unless you provide usable cores. So these will go in a box for that purpose.The pistons are frozen in the wheel cylinders and everything is corroded all to hell. A little tapping with a brass drift got the pistons out. Nothing good is happening here. The cylinder is not great with a lot of pitting. These cylinders are still easy to find but I will keep the old ones since some day they will be rare and they don’t take a lot of space. BTW, on this car the front cylinders are 1″ and the rear are 7/8″After cleaning and wire-wheel work here is the brake hardware. Most of this is good and can be used again. Not a lot of rust! The parking brake linkage on the left may in fact be nicer than what is on my car right now. We will see the next time I have my rear drums off.The adjusters and backing plates are decent. I sprayed everything down with an anti-corrosion spray for long term storage.The $200 dollar question is how good are the drums? New drums are hard to find and cost about that. Plus the machine work to move the hubs over and press in new wheel studs. Cross your fingers….080″ over. Not as good as I hoped nor as bad as I feared. I need to go look but I think mine are similar.Make a note for later…The other side would have just been a repeat of the first side. But it has left-hand threads on the wheel studs. The left-hand threads on my car are a little boogered up so I bought this thread-cleaning die. I tried it out on the spare diff first then on the rear wheel from my car. Worked great and cleaned up the threads without removing much metal. My plan was to use the lug nuts from my car to pull the hub on the spare diff. The problem is that once I cleaned up the threads two of the lug nuts from my car refused to start. They had boogered up threads as well. Worse yet, I only have one spare in my parts stash. I could have bought a left hand tap to clean them up but they only cost $1.50 each so I just ordered 6 new ones to keep from having this problem again. After a week wait for the parts to arrive I am ready to rock. This drum was not very tight at all and popped right off. This side actually has the cover that is missing from my car and the other side of this diff. It is just a strip of metal held in by that cotter pin you can see up by the backing plate. Here is what it looks like removed and cleaned up. According to the parts book there is a spring that helps keep in in place but I am not sure how that would even work. I found new ones at one of the Studebaker vendors but they are $4.00 for a sliver of sheet metal. Since I am not driving in snow or mud I think I am just going to forget about it. Except for this part this side was pretty much the same as the other. This drum is .080″ over too. Here is the diff ready to go back into storage. Brake parts are removed, corrosion treated and preventative applied, and the hubs are on loosely. I am going to leave the diff empty. I hope I don’t regret that. I lowered it back down and dragged it out to the shed. The other parts were labeled, added to my inventory, and stored away.
I also put the wheel back on my car with two new lug nuts. With the good nuts and clean threads they spin on by hand and torque easily. Much improved! I still have 5 good left-hand lug nuts, the next time I pull a front wheel I will clean up those threads and replace lug nuts as needed.
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