Packard Forum Index » Pre-War (1899-1942)

Checking brakes on the 1940 Super. Was just told in removing the rear drums, spray some brake parts cleaner onto the hub, using a fan or some sort of forced cool air. Do this several times, then immediately hit it with heat from a torch. He has been doing this for many years here in Las Vegas, and mainly works on large trucks. He explained you will be able to feel the hub getting colder to the touch, then when you hit it with the heat it will expand just a few seconds faster than the inner axle shaft. Used it today, worked good, or did I just have a bit of good luck.
Now want to put the drums back on, I know half say no anti seize, and half say yes, so I will probably just use a bit. But to me question, how tight on the axle nut? If I don't open these up for several years, don't want a fight. And don't want them too loose. In past years used an impact tool, but that might be a bit too tight.
Thanks

I don't have 1940 specs but typically about 240 lb-ft which may be more than your impact tool provides, use a torque wrench and with the taper surfaces clean and dry. If you reach the torque spec and are midway between cotter holes, either dress the washer or replace with a thicker or thinner one.

Sounds good, thanks. my half inch drive drive torque wrench only goes to 175 ft lbs. With all my weight cannot get to that, I can get to 145. Might try by 1/2 inch drive old Ingesol heavy duty impact.
Thanks

Hi Tolandis:

If you put a lubricant on the axle the result will be that less torque is needed to secure the drum. Significantly less.

On all of the Packards I worked on that came out of very long term storage I was able to remove the axle nut with a standard breaker bar. So the old timers were not running those nuts down with air hammers.

For the 51-54 Packards the manual says 200-270 ftlbs. So if you are using anti-seize a torque of 125-150 should be fine. I never ran Packards together with an impact and never saw a nut backed off against the cotter pin.

Today there are a lot of anal retentive tendencies even in the levels where I am working. One cause is that budget constraints are eliminating a lot of basic engineering rigor. In the old days Packard may have not had computer modules to play with, but what they did with what they had was pretty good.

my half inch drive drive torque wrench only goes to 175 ft lbs. With all my weight cannot get to that,

My 1/2 inch drive torque wrench goes to 275 and has an extra long handle (about 22 inches) which helps reaching that point though I still have to stand on it a jump a bit. Ask around among your car friends or local auto shops and see if you can borrow a more appropriate torque wrench. The correct torque (and a dry taper) will prevent damage to the key and keyways. Some folks believe the key and keyway drives the car; if that were true there would be no need for a taper fit in the first place - keep the taper surfaces clean and dry.

I had a somewhat unique way to torque mine. I have an 18" long box wrench that fit the nut. I put a mark at the 1 ft. mark and then put my 210lb. carcass on the mark. :)

What anti-seize does is reach the yield point at lower torque. That is, once the drum expands to a certain point the clamping force does not increase. That is why the torque range is so wide. So if you put anti-seize on the thing you could bottom the nut and distort the drum.

Another risk is that if the parts gall together, air pockets are created that can rust. Then the drum won't come off and slamming it with a sledge hammer can destroy the differential thrust block.

I have a 32 inch torque wrench and reaching the 200 ftlbs level is a resonable pull. If you have to bounce on a click type torque wrench that is not good for the wrench and it is probably clicking because the wrench is yielding (ie bending). So I suspect some of these torque wrenches are out of calibration. You also need to chock the wheels.

People have a habit of clicking torque wrenches over and over and that is not good. A torque wrench needs a steady pull to work properly. Once you stop moving, breakaway torque takes over which is higher than turning torque.

I guarantee that if you put a pipe onto a breaker bar (preferably 3/4 drive) and give a good steady pull you'll reach 200.