I bet there is not a factory built trailer rolling down the road weighing (with boat) less than 75 percent capacity of the axles. We must all be living on the edge.
Load range E or D tires
- Thread starter shanester
- Start date
Most of the trailer tires are not designed to go over 55mph. Keeping your speed down when pulling a trailer will save a lot of heat. This will help your tires.
Carlisle tires have a maximum speed rating of 65 MPH. I agree about the heat. In addition most tires on the road are probably under inflated. I see cars all the time going down the road with VERY low tire pressure.
As Dave indicated most consumer trailers are built with little excess capacity. On an overloaded axle you won't necessarily see spring/bearing/brake damage due to overloading.
This is often a result of manufacturers wanting to limit inventory and the number of different parts on hand. For instance one manufacturer uses the same bearings in their 3500# axle as they do in their 7000#, the same is often true for springs - many 3500# axles use the same springs as 4000# axles.
You will however see the tire camber going from positive camber to negative camber and frequently will see the axle tube arc downward due to overloading. (Many have an upward arch with no load so when loaded the tires will have little to no camber)
Large negative camber will cause the inboard edge of tires to wear.
Best image/diagram of this I could find is available here.
http://www.etrailer.com/Merchant2/graphics/00000001/pics/q/u/qu47906_800.jpg
(Couldn't find any live photos but usually you can see this at home and garden centres on weekends as people load up their little utility trailers with a few yards of soil!)
Over time a seriously overloaded axle will continue to bend downward over time due to fatigue, increasing the negative camber and cause tires to wear more rapidly.
The original poster while overloaded is not grossly so. 4000lbs - 400= 3600#
Assuming whole trailer weight was on scale at the time - axle and tongue. Tongue weight assumed 10%. Carried by tow vehicle axle not trailer axle. Moving more load forward to get a tongue weight of 15% - 600# would mean the axle isn't overloaded at all.
One other issue in relation to the original question - if going to load range E tires make sure that the new rims are rated for that tire pressure - not all are.
This is often a result of manufacturers wanting to limit inventory and the number of different parts on hand. For instance one manufacturer uses the same bearings in their 3500# axle as they do in their 7000#, the same is often true for springs - many 3500# axles use the same springs as 4000# axles.
You will however see the tire camber going from positive camber to negative camber and frequently will see the axle tube arc downward due to overloading. (Many have an upward arch with no load so when loaded the tires will have little to no camber)
Large negative camber will cause the inboard edge of tires to wear.
Best image/diagram of this I could find is available here.
http://www.etrailer.com/Merchant2/graphics/00000001/pics/q/u/qu47906_800.jpg
(Couldn't find any live photos but usually you can see this at home and garden centres on weekends as people load up their little utility trailers with a few yards of soil!)
Over time a seriously overloaded axle will continue to bend downward over time due to fatigue, increasing the negative camber and cause tires to wear more rapidly.
The original poster while overloaded is not grossly so. 4000lbs - 400= 3600#
Assuming whole trailer weight was on scale at the time - axle and tongue. Tongue weight assumed 10%. Carried by tow vehicle axle not trailer axle. Moving more load forward to get a tongue weight of 15% - 600# would mean the axle isn't overloaded at all.
One other issue in relation to the original question - if going to load range E tires make sure that the new rims are rated for that tire pressure - not all are.
Wet your tow vehicle rear tires and the trailer tires and then drive 10ft into a level surface. If the axle of the trailer is well aligned the wet tracks should follow those of the tow vehicle with no deviation. As 4,000 lbs is a significant load for a single axle you need to insure you use trailer rated tires (ST), the maximum towing speed is 65 MPH, they should be inflated to the maximum pressure stamped on the sidewall, the combined load bearing capacity should exceed by 20% the actual load and the expected life of a trailer tire is between 5,000 and 12,000 miles. They might not give you longer mileage but will reduce the likelihood of a blow-out.
Great! That never crossed my mind. I did a search at a few places and sure enough the ones that actually list a max psi are all under 80 psi. Does anyone know of any places to get steel wheels rated for 80 psi? 15" 5 lug 4.5" bolt circle. Galvanized would be great. I will try to remember to call Carlisle tomorrow and ask as their website only shows max weight. This is the brand I was going to go with from Discount Tire. I will bring that issue up with them as well to see what they say.
This shows the wear on the inside of the tire. Left side of the photo. Virtually all the excessive wear is on the first inside section of thread and it seems pretty even around the tire. 1500 miles on a new st205 75 14 C range. I guess it would be best to go up in size and load range but I need to get the wear issue fixed first.
Srust - you mention this type of wear since trailer/boat was new. Strange thought - any chance the axle could have been installed upside down at the factory? Maybe done on a late Friday afternoon? You could check this at a place that does alignments or a quick and dirty check would be to put a straight edge vertically next tires on unloaded trailer and see if they converge at the top!
I know this has been brought up many times in this thread but what tire pressure do you run?
Is this possible? My axle has tabs welded to it that align to the spring bolt.
whether it is possible in this case to install the axle upside down would depend on the spring/axle combination but yes it usually can be done. (they can also be installed backwards as well - left becomes right - usually only has an effect on braking system!) Some axles are designed for over spring installation while others are designed for installation under spring. Flipping an under spring axle to go over spring or vice versa would result in the axle being upside down unless new axle perches were welded on. RV'rs move from underslung to overslung to increase clearance - sometimes they don't do it right!
I did think of that but it seems to be installed correctly. Looking at the photo (hub on the right) you can see the axle is a 2x 3 rectangle and the spindle is welded in on the top side of the axle...what I would expect. It has holes top and bottom for the leaf spring dowel to fit into so my guess is it can be an over or under setup. So I finally got smart and blocked up the trailer and took all the weight off the axle and put a straight edge on the axle. It has about 3/16th of an inch of negative camber in the 4 foot length of my straight edge. I think it might be a bit bent. I can only imagine how much worse it gets over the whole length of the axle with the weight of the boat.
as for air pressure I run the max for the tire...50lbs for these.
I called Carlisle this morning and they said that the max rating is 50 psi on their 15 X 6, 5 lug 4.5 bolt circle. I can't find any wheels rated for 80 psi. The best I found is 75 psi which means that I will have to go with load range D. If I went to a six lug 15" then they are rated for 80 psi.
I can't find any wheels rated for 80 psi. I am looking for galvanized 15", 5 lug, 4.5 bolt circle. I am considering going with Americana brand (made in China) with a max 75 psi and putting the load range E tires on them. With only 2,000 lbs or less per tire I doubt I would have any issues with going 5 psi over. The 6 lug version 15" is rated for 80 psi. They are most likely the same rim with a different center welded in. The Carlisle brand wheels (Made in USA) are only rated for 50 psi. Where do they come up with these numbers? I can understand the weight rating (I think they are tested on a load machine) but the psi?
I called these people about their wheels and they said max 100 psi but would need high pressure valve stems. I asked where they come up with the max psi rating and he was not sure.
http://recstuff.com/15x6-5-4.5-galvanized-spoke-trailer-wheel.aspx
They are made in China by JG Wheel.
http://recstuff.com/15x6-5-4.5-galvanized-spoke-trailer-wheel.aspx
They are made in China by JG Wheel.
I just had mine on the scale and boat with trailer came to 3400 lbs. That is lightly loaded....no motor, gas, or battery. I think your thought of 2400 lbs for the boat may be close possibly a bit low though I don't know what my trailer weighs. Normally all we put in the boat when traveling is the battery, gas and the motor depending on how much room we have in the truck. So subtracting for the 200lbs on the hitch and add some for battery and misc gear I guess I am rolling at 3400-3500 pounds on the axle. We put everything up forward of the axle or shove it all into the V berth so I think the hitch weight probably increases a bit when we travel.
The old axle had a 3/16 wall thickness on a 2x3 rectangular tube. The new 3500 lb axle I am looking at has 1/4 wall thickness on a 2x2 square tube. The next size up seems to be 5000lb and they all seem to be 3 inch diameter tubes. My problem is the old axle is very close to a frame brace on the backside and I don't think I have the clearance for a wider axle unless I move everything forward a bit. How wise is it to just put in a new 3500 lb axle? I am on a bit of a tight timeline and Have even though about pulling the old axle out and having it straightened and use it just once more for this trip and after I would have the time to rebuild the trailer and think it all through. Any thoughts on that?
Since you have been running on a 3,500 lb axle for all those years I would just put another in. If you have the room under the fenders go with 225/75/15 tires load range D. I would tell you to go with load range E but haven't figured that out myself. The difference in diameters is about 2 1/8" so would need half that in extra fender clearance. Yeah the Sirius is more like 2,600.
I will gain 1 inch changing from the thinner wall 2x3 axle section to the thicker wall 2x2. Sweet.
Do you have a round or square axle? When I put the weight back on the axle it was out almost 1/2 inch in the 4 foot length of my level.
My axle is a round tube Dexter with through the axle lubing and 4" drop. When the weight was off your axle was is bowed upward any? Did you pay attention to the camber change of the wheels with the weight off and then back on?
I decided against galvanized wheels based on some I have seen and some reviewers also saying the finish was bad. I also would like to have USA not Chinese made wheels. Carlisle is the only brand I found (galvanized) made in USA but are only rated for 50 psi. My white powder coated wheels lasted 14 years (half the time launching in salt). So I ordered silver wheels thinking that they might look better than the galvanized finish or white wheels after rusting.
http://www.etrailer.com/Tires-and-Wheels/Dexstar/AM20537.html
I still have not decided on load range E or D tires but these wheels do have the highest psi rating I can find in my size.
http://www.etrailer.com/Tires-and-Wheels/Dexstar/AM20537.html
I still have not decided on load range E or D tires but these wheels do have the highest psi rating I can find in my size.