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

I'm not sure if I have an issue or not so I'm hoping that more experienced minds can advise - The rear wheel hubcaps on my 1940 Packard are always hot to the touch after a drive. I've checked the temperature and have seen around 115 degrees which is much hotter than the front hubcaps which are just warm. What is the guidance on the brake temperatures transmitted to wheels and hubcaps and is it normal for the rear wheels to be hotter? Presumably they are carrying more load but the weight shifts forward when braking. Thoughts?

The rear axle will run above ambient temperature if the car is driven much, due to normal friction and fluid friction in the axle lubricant. Some of that heat will find its way to the rear hubs and drums. If the brakes don't drag significantly, the heat is bound to be coming from normal temperature rise in the drive axle. Of course, brakes generate heat when they are used, and some heat from the engine will pass under the car and reach the rear axle.

You can also get heat generated from the drum taper if the nut hasn’t been torqued sufficiently.

One additional point - I've confirmed that the parking brakes are not dragging so that is not the issue.

Could also be a rear wheel bearing that is bad or way over due for a greasing. But that usually wouldn't be both sides, unless they were both bad.


I'd jack up the car (jack stands under the axle tubes), spin the wheels in the direction of forward travel, and listen for any odd noises or signs of dragging. Shake the tire in and out and see if there is any looseness, which could point to a loose taper.

If you have never repacked the rear axle bearings, then they are probably overdue.

Thanks to everyone for your input. I'll continue to diagnose further.

George40

If you decide to jack the rear of the car there is one more check that you might make, that is check the drag on the wheels cold, and then depress the brake pedal and reaffirm the drag is the same once the brakes have been released. You’re checking whether the brake shoes retract properly. A restriction in the flexible brake line could (emphasis on vague) be inhibiting/slowing the retraction of the rear shoes. A mal-adjusted brake pedal could inhibit proper shoe retraction on all four wheels, so you might consider jacking-up the front wheels and conduct the same check. The use of a helper pressing on the brake pedal will speed-up the process. The wheel should release as soon as the brake pedal is released.

dp

Good point. Thanks.