Questions about tire and axle loading

[kevg]

I've got a Ford F250 3/4 Ton 2014 SRW SuperDuty SuperCab XLT 4x2 6.75" Short Bed Gas Engine truck.

The first question is about the tires which I think I know the answer to: I have Load Range E tires with a max load of 3195#. My GVWR is 10,000#. Focusing on the rear tires, my rear GAWR is 6200#, so is it correct to say that the weaker link is the axle (at 6200#) because the two rear tires can support 3195*2 = 6390#?

The second question is that I went to get the truck weighed at a scale and the rear axle load (without camper) is 2820#. I believe this means I can put up to 6200-2820 = 3380# on the rear axle right?

If so, does all of the weight of a truck camper go on the rear axle? If so, then that would mean that my camper wet weight can't go over 3380# right?

I know the GAWR can't be increased, but do things like a rear stabilizer bar do anything for safety or is that just for ride comfort?

[kevg]

ticki2 wrote:

kevg wrote:
Maybe I'm missing something, but on page 84 of that PDF, the rear axle says 6200 for a Ford F250

It is confusing , if you look earlier were it gives the payload you will see that the axle rating is being generated by the spring rate , not the actual axle rating . The 350SRW and 250SRW use the same axle , they change the springs and tires and get a higher axle rating .

Ahh, I see thanks, so basically if I want to beef up the rear, I need better wheels and springs (and rims?). Do you have any suggestions for those?

[ticki2]

kevg wrote:
Maybe I'm missing something, but on page 84 of that PDF, the rear axle says 6200 for a Ford F250

It is confusing , if you look earlier were it gives the payload you will see that the axle rating is being generated by the spring rate , not the actual axle rating . The 350SRW and 250SRW use the same axle , they change the springs and tires and get a higher axle rating .

[kevg]

lawrosa wrote:
What TC are you looking at?

Lance 855S 2015

[kevg]

Maybe I'm missing something, but on page 84 of that PDF, the rear axle says 6200 for a Ford F250

[kevg]

ticki2 wrote:
I agree with Buzzcut . I think you will find that the rear axle rating is based on your spring pack . If you change your tires ( they are close to limit) and add to the spring pack it will not change the official GVWR , but for all practical purposes ( actual performance ) it will . Ford had many options , yours happens to be one of the lower rated .

https://www.fleet.ford.com/truckbbas/topics/2014/14_SD_Pickups_SB_Updates.pdf

That link is perfect, thanks!

[ticki2]

I agree with Buzzcut . I think you will find that the rear axle rating is based on your spring pack . If you change your tires ( they are close to limit) and add to the spring pack it will not change the official GVWR , but for all practical purposes ( actual performance ) it will . Ford had many options , yours happens to be one of the lower rated .

https://www.fleet.ford.com/truckbbas/topics/2014/14_SD_Pickups_SB_Updates.pdf

[kevg]

I'll research which components are limiting me and replace those. Thanks!

[Buzzcut1]

Ok the Ford Sterling axle is rated at 9800 pounds, it is not your weakest link. Somewhere in your tires, rims, leafs, shocks is the lowest rated component.

[tonymull]

Yeah you are pretty much right. But don't forget that the camper itself is not all you need to allow for. There are passengers and all the stuff you put in your camper. Usual allowance is 1000lbs. It is quite true that ratings are usually conservative, how conservative you never know, but part of that is to allow for smacking the occasional speed bump or pothole or other roughness, it's there for a reason. It's best not to exceed your payload rating even if many people do. Still you will have plenty to choose from, just don't expect double slide outs and 11 or 12 feet of length.

[twodownzero]

While I do not advocate overloading your truck, the GAWR is usually restricted by wheels and/or tires. The axle assembly itself is probably rated for more weight than the wheels and tires that were installed on it from the factory, by a significant margin.

[lawrosa]

kevg wrote:
I've got a Ford F250 3/4 Ton 2014 SRW SuperDuty SuperCab XLT 4x2 6.75" Short Bed Gas Engine truck.

The first question is about the tires which I think I know the answer to: I have Load Range E tires with a max load of 3195#. My GVWR is 10,000#. Focusing on the rear tires, my rear GAWR is 6200#, so is it correct to say that the weaker link is the axle (at 6200#) because the two rear tires can support 3195*2 = 6390#?

Yes your axles are the weakest link. IMO never go over axle ratings. Tow with tires inflated to max pressure.

The second question is that I went to get the truck weighed at a scale and the rear axle load (without camper) is 2820#. I believe this means I can put up to 6200-2820 = 3380# on the rear axle right?

Yes that is correct. You can put 3380 on the rear axle. Make sure you account for other people gear and a full tank of gas. That # may/will be reduced.

If so, does all of the weight of a truck camper go on the rear axle? If so, then that would mean that my camper wet weight can't go over 3380# right?

Yes most of the weight will be on the rear. Some on the front so its hard to determine how much.

What TC are you looking at?



I know the GAWR can't be increased, but do things like a rear stabilizer bar do anything for safety or is that just for ride comfort?




Correct. Any additions are just for stability and leveling functionality. You normally cant increase the GAWR.