I've noticed my rear hubs are awfully hot to the touch this summer after cruising at no more than 50 mph for an hour on the highway. No dragging brakes here. I am going to get a contactless thermometer soon. Dana 80 rear, Ford says 9,450 lb on the GAWR rear, is this derated?

How's that fluid level? They play with GVWR but I see no reason that they would play with axle ratings. What are you towing?Why don't you have an infrared thermo already? If you have a covid forehead tester you already have one.

bucky wrote:How's that fluid level? They play with GVWR but I see no reason that they would play with axle ratings. What are you towing?Why don't you have an infrared thermo already? If you have a covid forehead tester you already have one.Perhaps his rear end has Covid?

Switch to a full synthetic gear lube.

I assume we are talking about the hubs (out by the wheels), not the differential (aka: pumpkin) in the middle.Unless you are heavily loaded or have other reason to believe you are putting more strain than normal on the bearings, I would pull them apart to make sure they still have grease in them and there is no other apparent damage.

Full floater outer axle bearings are oiled by the diff, not grease lubed. 9450 is about right, but axles get “derated” depending on the vehicle they’re attached to. And how hot is awfully hot? If you can hold your finger on them, nothing is burning up. And presuming you have full diff oil and within service limits.

Let's talk Dana 80 axle temps | Good Sam Community

bucky
Explorer II
Jul 22, 2022
How's that fluid level? They play with GVWR but I see no reason that they would play with axle ratings. What are you towing?
Why don't you have an infrared thermo already? If you have a covid forehead tester you already have one.
PButler96
Explorer
Jul 22, 2022
bucky wrote:
How's that fluid level? They play with GVWR but I see no reason that they would play with axle ratings. What are you towing?
Why don't you have an infrared thermo already? If you have a covid forehead tester you already have one.

Perhaps his rear end has Covid?
theoldwizard1
Explorer II
Jul 22, 2022
Switch to a full synthetic gear lube.
valhalla360
Navigator
Jul 22, 2022
I assume we are talking about the hubs (out by the wheels), not the differential (aka: pumpkin) in the middle.

Unless you are heavily loaded or have other reason to believe you are putting more strain than normal on the bearings, I would pull them apart to make sure they still have grease in them and there is no other apparent damage.
Grit_dog
Navigator
Jul 22, 2022
Full floater outer axle bearings are oiled by the diff, not grease lubed.
9450 is about right, but axles get “derated” depending on the vehicle they’re attached to.
And how hot is awfully hot? If you can hold your finger on them, nothing is burning up.
And presuming you have full diff oil and within service limits.
enblethen
Nomad
Jul 22, 2022
I would suggest changing the fluid. It is easy to do. Biggest issue is to insure you drain fluid fully. Will need to jack up each side one at a time to get old fluid out of hubs. You must do the reverse when filling to get new fluid into each hub area. Final fill level would be done after accomplishing alternating.
Inspect old fluid for metal debris.
OP: do you have rear drums or disc brakes? My discs run hotter than drums!
Lwiddis
Explorer II
Jul 22, 2022
Cruising for an hour at 50 MPH in the Summer will heat everything up to operating temperature. Thirty minutes will too! If anything is above operating temperature, have it checked.
bighatnohorse
Explorer II
Jul 23, 2022
Yes. The Dana 80 is de-rated by Ford to match the tire load capacity.
The Dana 80 is rated for 11,000 pounds by it's manufacturer.
Huntindog
Explorer
Jul 23, 2022
valhalla360 wrote:
I assume we are talking about the hubs (out by the wheels), not the differential (aka: pumpkin) in the middle.

Unless you are heavily loaded or have other reason to believe you are putting more strain than normal on the bearings, I would pull them apart to make sure they still have grease in them and there is no other apparent damage.
You have obviously never greased your rear ends bearings. I am trying real hard not to laugh at that statement.
Oh to heck with it.:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B

Another internet expert exposed.
PButler96
Explorer
Jul 23, 2022
Huntindog wrote:
valhalla360 wrote:
I assume we are talking about the hubs (out by the wheels), not the differential (aka: pumpkin) in the middle.

Unless you are heavily loaded or have other reason to believe you are putting more strain than normal on the bearings, I would pull them apart to make sure they still have grease in them and there is no other apparent damage.
You have obviously never greased your rear ends bearings. I am trying real hard not to laugh at that statement.
Oh to heck with it.:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B:B

Another internet expert exposed.

I just pulled everything back there apart at the campground on my 2500, I couldn't find a zerk, do I need to pack some grease in by hand after all this oil stops dripping out? Sounds like a messy proposition lol.