'40 Mercury rear end

1939mars

1939mars

Senior Member
I am helping with a '40 Mercury. The rear axle was partially disassembled by a well meaning but uninformed person that is pretty strong. Strong enough that on the passenger side the axle end is mushroomed over and the drum is cockeyed to the backing plate. I tried my KR Wilson puller and the drum did not budge. We had penetrating oil on it and used a breaker with a 3' cheater. There was so much tension on it that the base of the tool was starting to spread! I am not sure what is bent and damaged in this unit so I am not sure that the tool is going to do its thing.

My question is, does anyone have any ideas aside from heat (my next step) to get this drum off? The drum is destroyed already so I am not worried about damaging it. Whatever I do, though, I do not want to damage the ring and pinion so that the whole thing can be rebuilt with those two existing parts.

Alternatively, does anyone know of a 39/40 Mercury rear axle in the Los Angeles area?

Thanks,
Scott
 
The ring/pinion will survive, and with any luck at all, housing will also survive, but sounds like the axle bit the dust. KRW puller did it's job, which was to release the drum from the axle. Beyond that, your handbrake was likely set, shoes rusted to the drum, drum ridged from shoes. In any case, the shoes are cocked now and will not recede, will only get cocked tighter the farther the drum moves outward. Nothing to do but the red wrench now. Concentrate on the inner edge of the drum, that's where the shoes are cocked and binding.


BTW, you do know that the pinion is one piece with the driveshaft? Won't transplant to a Ford.
 
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BTW, you do know that the pinion is one piece with the driveshaft? Won't transplant to a Ford.

Yes, but.... many have been converted by a competent machinist with flathead knowledge. In the past, are sometimes found to have 3.54's, hence the reason to convert them for Ford use. Just saying...
 
The last time I heard a story like yours it turned out that the axle had safety hubs installed. Any chance that is your problem?

Charlie Stephens
 
ford38v8 said:
The ring/pinion will survive, and with any luck at all, housing will also survive, but sounds like the axle bit the dust. KRW puller did it's job, which was to release the drum from the axle. Beyond that, your handbrake was likely set, shoes rusted to the drum, drum ridged from shoes. In any case, the shoes are cocked now and will not recede, will only get cocked tighter the farther the drum moves outward. Nothing to do but the red wrench now. Concentrate on the inner edge of the drum, that's where the shoes are cocked and binding.


BTW, you do know that the pinion is one piece with the driveshaft? Won't transplant to a Ford.
Click to expand...
Alan, I knew the Merc was one piece but never knew why that was. Do you?
 
Mike & Alan


The the OP original question in post #1, and I quote "Alternatively, does anyone know of a 39/40 Mercury rear axle in the Los Angeles area?"


There is no difference in the axles between the Mercury & Ford rears is there???


I know about the longer drive shaft/tubes and just learned of the pinion BUT axles???
 
When checking for safety hubs the first hint is to look for two bolt heads and two studs with nuts holding the backing plate to the axle housing. Ford used four bolts.

Charlie Stephens
 
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To the OP, if not safety hubs, it's possible a broken & chewed up axle key is causing everything to bind up.

With that much torque on it, I would think the flange of the hub is now tweaked a bit. You may have to torch it off and get a replacement axle shaft.

To the one piece driveshaft/pinion, I'm wondering could it be to reduce vibration by not having a coupler in there? Mercury was a step higher end vs. Ford at this time, right?

Just a guess I'm throwing out there.
 
Had one that wouldn't come off normally; used an Air Arc to cut a big chunk of the drum off and then cut the hub along the key and across the inner raise until it popped. Axle was not hurt and neither was the bearing.
 
Suggest to install the drum puller with substantial pressure and leave it on at least overnight. Check the next day if it is slacken tighten it again and it may come off. Hit the hub with a hammer not to drive it on but to shock it with vibration.
 
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