Your trailer probably has 6000lb axles.  So you can carry 12,000 on the axles.  4 tires at 3042 = 12168 which matches up with your axles.

When you hook up, approximately 25% of the trailer weight is on the Gooseneck ball.  On your trailer 13600lbs * 25% = 3400lbs on ball leaving 10200lbs on tires and axles. So you are within your ratings.

If you upgraded to a "G" rated tire.  Which is rated at 3750 lbs at 110 psi  That gives you 15,000 lbs total on 4 tires. These are what are commonally used on trailers with 7000 lb axles. If you upgrade to "G" tires, make sure your rims will are also rated for the extra weight and will tolerate the higher air pressure.

"E" rated tires work fine, IF you stay within your weight limits.  If your trailer weighs more than the tires are rated for, Then they are not going to hold up.

Make sure you run them at the correct pressure. If the tire is rated at 3040 lbs at max pressure, You can't expect them to support that load at 60% air pressure.

5 year old tires are still 5 year old tires regardless of the rating and need to be replaced.

Your rims should be stamped for their working load. My new trailer came with "G" rated Goodyear tires and the rims are stamped for 3750lbs. at 110psi

I appreciate trailer makers putting a quality tire on a new trailer.  My last two horse trailers have come with a Goodyear Trailer tire.  (Load range "E" on one and Load range "G" on this new one)  They seem to hold up so much better than the no-name tires made in China that came on my equipment trailers. I put almost as much weight on flat bed equipment trailer hauling a skid loader or mini hoe as I do a horsetrailer.

I've kind of had the same problem with tires with some different weights.   I've got 4000lbs per tire on my horse trailer (sundowner 34 on the floor with a slideout.)  Trailer weighs in at about 20K with 4K on the pin.  That leaves 4K per tire.  Needless to say my "speced" E rated tires are getting crushed. 

I had two choices.  G rated tires (3700lbs) or go to a 17.5 rim and J rated tires (6000 lbs).  I'm going with the J rated tires since the G rated doesn't get me where I need to be anyways.  At discount tire they have Kuhmo J rated tires for 210 a tire but the new wheels cost me a bit less than 200ea. 

Moral of the story.  $1600 later and I'll have a trailer that is finally where it needs to be.   It's a bunch of money today but the piece of mind is worth every penny. 

Later,

Chad

Our Goodyear dually tires had almost worn through on either side of the inside tire,both sides of each tire on both tires.The tire dealer where we had them rotated said it is a wonder they did not come apart.

Goodyear was notified and adjustment was made.

I've had some bad "Goodyear" tires too.

I put 12 ply Kumho's on my Titan in '03.  No flats or blowouts since.  Not sure how many miles I've put on them...the trailer gets a fair amount of use and sees some ugly gravel roads fairly often.  I'm usually pulling 3-5 horses. 

Anyway, just wanted to share my good experience with these tires.  Good luck!

Anyone who may be interested, I am contemplating upgrading to H rated tires on my fiver and it will require my going to 17.5" wheels & tires.

I will have 5 Goodyear (G rated) G614 285/75/16's - four with nice Aluminum wheels and one on steel wheel. Four on Aluminum have less than 5000 miles, spare has never been on the ground. No flats on any. Pressure always maintained at 110 as factory prescribed.

These tires are in Texas near Ft Worth.   Anyone interested may contact me to discuss price. 

Hey Rugged, did you get them in UT or up here?  (guess who THIS is???  LOL)  What dealership?

I have load range G on my trailer with 7000 lb. dexter axles.  It has 32 Ft. on the floor. Wonder how you got load range E on there?????

Have you weighed your truck and trailer at the scale loaded yet??? If you haven't I would definetely recommend it. Takes all the guess work out.