Axles, tires, & overall weights

[WoodcarvingGypsy]

I've been looking (not seriously) at new campers & have a question that I can't seem to get a straight answer to. I'm not going to make the mistake of asking a salesman as they only seem to know one answer.



I currently have a 2011 Seville 35CKS & it's approaching 10 years old so I got curious. One thing I have wondered about is axle loading & if the axles are heavy enough. What prompted the question is really 2 issues, 1) I have to replace the outer bearing at least every other year or maybe every depending on how much we pull it.



My need to figure out (make the trip to Elkhart) and have each wheel weighed to get a real answer on how the camper is loaded. I look at the brochures on new ones and see that the axles are 7,000 lb units and know that the axles on my Seville are 7,000 lb as well. Total tow weight for us is just about 23,000 lbs (truck & trailer) so I really need to take it and just accept that I need to unhook, weigh, and then rehook.



So, given that the new camper is showing 16,000 lbs as a max load, how do they get away with 7,000 lb axles. Logic to me seems to indicate those should be at least 8,000 lbs. I know that the manufacturers tend to use the least cost part possible but I have to wonder should the axles (and bearings) be heavier.



I know that if I were to upgrade from load range E to G, I'd need new rims. If I keep this camper (highly likely) then I may need to look into the whole weight, axle, tire combination along with the necessary suspension changes.



Where would I start to figure out what exactly needs to be done, who would I go to for advice (definitely not Camping World), and where would be the best place to get this type of work done.



Sorry about this rambling a bit but I knod of did a mind dump on the question.



Thanks and happy camping.

[dagst1]

I will give this a try.

You have 2 7000# axles = 14000 on the tires.
16000 max load - 20% for the hitch weight = 3200.
16000 - 3200 = 12800 on the tires at max load.

Quality wheel bearings if properly greased and adjusted should last a very long time. My camper is a 05 and it still has the original wheel bearings. I remove them each spring and hand pack them then periodically thru the year i raise the wheel and while turning add grease thru the fittings.

If you live in a rural area try to find a coop elevator to weigh your rig. If not busy like during harvest you can spend some time there and get the weights you want.

Another thing people over look - what are your springs rated at? Also check the air in your tires and try to set them at a little above the weight of the camper. If for example they are rated at 4000# at 80 psi then thats 8000# per axle. The camper will ride better at a lower psi and still be whiten the load rating of the axle..

The tires and springs all add to the ride of the camper. Too stiff and you will shake it apart - instead of absorbing the bumps it will jar everything and ride very rough.

Hope this makes a little sense. Its all made to work together.

[WoodcarvingGypsy]

You may have hit the problem with "quality bearings". The factory original bearings (2 failures ago) were neither NTN or Timken.



This whole thought process started with a tire failure on the roadside rear (Sept 2015), then a bearing failure on the same position (Oct 2017) which resulted in new bearings & backer plates (self-adjusting). I pulled all the bearings to pack in the fall of 2019 & found that all were in some sort of bearing failure so I pulled all the wheels, had the tires balanced, added TPMS sensors, and replaced all the bearings and races.



I'm looking forward to pulling the outer bearings when I get home and having a look.



I've got a co-op just down the road so I will check with them and then take the Seville & truck down there for a weight check. That should be enlightening. I will also check at the local Pilot/FlyingJ & see if I could get all axles weighed at the same time.



I think my Carlisle 235/80/16 ST (either 3,520 or 3,640 lbs, I'll have a look in the am) so that will be data that is useful.



Your point about weight and pressure changing how the coach handles & rides is important. I need to look into that more. According to the Carlisle site, they make a load range F tire that might be worth looking into.



More data and observations to follow. Thanks for your help and advice.

[Photobob]

This is what I do to check if I am within loading specs for the TV, Trailer and the Combo Weight. What I found is that for my Expedition the rear axle load capacity is the restraining factor.

I use a CAT scale that is found at many truck stops. It can weigh all the axles at once.

Example:
Date: 04/22/2019
Scale: Pittsboro Love's CAT Scale
Weighing Number: 1
What was weighed: TV and Trailer
Weight Distribution Hitch Set: Yes

TV Vehicle Front Axle
Gross Axle Wt. Rating - Front (lbs.) Front Driver Side Sticker = 3550 lbs
Steering Axle Scale Weight = 3000 lbs
Steering Axle Diff. Negative is good, Positive is bad = (550) lbs

TV Vehicle Rear Axle
Gross Axle Wt. Rating - Rear (lbs.) Front Driver Side Sticker = 4250 lbs
Drive Axle Scale Weight = 4300 lbs
Drive Axle Diff. Negative is good, Positive is bad = 50 lbs
To correct this I empty the water tank

TV Vehicle Weight
TV GVWR Front Driver Side Sticker = 7500 lbs
Calculated Vehicle Weight from Scale values (Ft + R) = 7300 lbs
Vehicle Total Weight Diff. Negative is good, Positive is bad = (200) lbs

Trailer Weight
Trailer GVWR Sticker = 7500
Trailer Axles Scale Weight = 7220
Trailer Total Weight Diff. Negative is good, Positive is bad = (280) lbs

Combo Weight
TV Combo GVWR Specification = 15000 lbs
Total Combo Weight Scale Weight (lbs.) = 14520 lbs
Total Weight Diff. Negative is good, Positive is bad = (480) lbs

WD Jacks Setting: 10 inches

Water Tank Status: Full (have to empty this to take weight off the TV rear axle)

TV Front Passenger: Yes

TV Rear End Load: Empty

Trailer Rear End Added Weight = 266 lbs (added this to reduce the overall tongue weight - Crossroads put the axles to far back and pushed most of the trailer weight forward)


Current Trailer:
Mfg: Crossroads
Brand: Sunset Trailer Super Lite
Year: 2019
Model: 289QB

Suspension Changes:
Axles - Replaced the two 3500 lb axles with two 7000 lb axles
Springs - Match 7000 lb axles
Wheels: 14C at 65 psi to 19.5G at 80 psi to handle 7000 lb
Brakes: Electric Drum to Hydraulic

End result our 2012 Expedition with factory towing package can tow this trailer.

Sway is dealt with by the ProPride 1400 BP hitch. Does a very good job. Plus can throw 600 lbs from the rear axle to the front axle of the TV.

My two cents on how dealt with all needed weight checks to tow properly within specifications

Good Luck

[mark5w]

Great details. Thanks for posting.