Mopar wheels on a travel trailer

[73Coupe]

My wife and I bought a vintage "canned ham" trailer a few years ago and I'm finally starting to work on it. It's a '61 Aloha, weighs about 2000 lbs., loaded.
First thing is putting some better looking wheels on the thing. It came with the standard "boat trailer" type of wheels (not original to the trailer), white with the triangle shaped slots. While functional, they look bad. These are 15 x 7 JJ wheels.
Fortunately the lug pattern is 5 on 4-1/2". And I already have a Mopar wheel from my 73 NY'er trunk spare. It is 15 x 6 JJ.
And I recently bought another Mopar wheel that I discovered is 15 x 6-1/2" JJ, when I compared it to my 73 spare. Dang!

So, could I safely use a 15 x 6 on one side and 15 x 6-1/2 on the other? Would it make any difference? Or should they be exactly matching widths? Or should I scrap them and try to find 15 x 7s?

The tires are good, they're ST205-75-R15s, rated for extra load.

Existing wheels:

73 NY spare wheel test fit on trailer- 15 x 6

two mopar wheels rim to rim

Note the difference in width

 

[300rag]

I would keep them the same and stick with 7".

 

[Newport 66]

15x7's work great. That's what I have on our camper with 215/ 75-15 tires.

 

[73Coupe]

How common are mopar 7" steelies?

Also, does anybody know where I could look up the load rating on mopar stock steel wheels?

 

[Polara_500]

Not common - and I've heard/read that a person should really use trailer wheels on trailers, especially if a multi axle unit. Something about side loads that car wheels aren't designed for.

 

[commando1]

Not common - and I've heard/read that a person should really use trailer wheels on trailers, especially if a multi axle unit. Something about side loads that car wheels aren't designed for.

You're thinking of the reasoning for using car tires vs.trailer tires.
As far as car/trailer wheels is concerned, the issue is the OFFSET of the wheel. Paying attention to the offset of the trailer wheel is critical to not burning up your axle bearings.
That's why I'm not crazy about using different widths on the same axle.

 

[patrick66]

I sold trailers for several years. On a single axle, car wheels are fine. On a tandem axle, they are NOT. You always want to use trailer tires, regardless, because of stiffer sidewalls. Car wheels on a tandem axle are a bad idea because of torsional forces they are not designed to withstand. These forces don't exist on a single-axle trailer.

 

[Darter6]

Check wrecking yards for 80's Dodge Diplomat, Grand Fury,and Rear Wheel Drive New Yorkers. They came with 15x7 steel wheels and some had the 15x6 1/2 too.The last set I got were from a 85 Diplomat in 15x7.

 

[73Coupe]

I sold trailers for several years. On a single axle, car wheels are fine. On a tandem axle, they are NOT. You always want to use trailer tires, regardless, because of stiffer sidewalls. Car wheels on a tandem axle are a bad idea because of torsional forces they are not designed to withstand. These forces don't exist on a single-axle trailer.

Thanks...Mine is a single axle trailer.

The wheels are the concern. I will use trailer tires that I already have.

I've found other information that brings up the topic of offset like Commando pointed out. It seems that trailer wheels have a positive offset so the tires don't sit proud of the trailer wall.

Here's what etrailer offers....looks just like a car wheel. I will compare to my 'Ma' wheels... Edit...the mopar wheels also have a 1/2" offset.

Dexstar Conventional Steel Wheel with Offset - 15" x 6" Rim - 5 on 4-1/2 - Black Dexstar T

 

[300rag]

There's a guy on this forum that has road wheels on his trailer, right @azblackhemi ?

 

[FURYGT]

I agree with the bearing and other potential problem issues noted above and feel that a 15 x 7 wheel IMHO is to wide for a trailer that uses a 14 or 15 inch wheel. Typically trailer tires are narrow so that there is less stress on the tire and wheel when one of the tires is pivoting and essentially sliding/scraping across the pavement. Glad to hear that you are planning to run trailer specific tires.

 

[cbarge]

How common are mopar 7" steelies?

Also, does anybody know where I could look up the load rating on mopar stock steel wheels?

More common than you would think.All M bodies (diplomats,5th Ave) came with 15x7 steelies. Not to mention the cop rims over and above that.
Not sure regarding any web site that has load range data..

 

[MrMoparCHP]

If you are interested I have some 15x7 wheels, I am interested in your 15x6


Alan

 

[CBODY67]

When you use a P205 width tire on a 7" rim, it puts the sidewall in a more vertical orientation to the road, rather than a "bow shape", which effectively stiffens the sidewall more than if it was on a (more normal for cars) 6" width rim. It ALSO means a higher pressure might be needed to keep the center of the tread flat against the road, which will reduce sidewall flex further, possibly enhancing tire life more.

Tire "age" can be worse on trailers than for cars. Two couples took a car to MI to a national car celebration in '03. The owner bought a new tire for the spare (30" enclosed car trailer, doublt axle; F250 4dr PS diesel). Before they got from DFW to MI, they'd changed all four tires on the trailer. After the first two, I understand it looked like an Indy Pit Stop! In other car trailer issues with some other members of that car club, every time somebody towed a car to a meet, there were tire problems on the trailer. Possibly that trailer tires, as they sit a bunch between uses, more moisture can get into the tire innards that doesn't regularly get cooked-out with regular use?

Offsets can be more important (bearing load issues) on trailers than on cars. By comparison, the trailer axle components are not as beefy as car components might be AND some are better than others.

Rather than worry about Chrysler-spec wheels, what about putting some "flatter" Chrysler wheel covers, if they'll lock onto the trailer tire rims?

I have seen some weight ratings for aftermarket wheels (on their websites). Most are about 1500-1700lbs/wheel, in the 15x7 size.

Many of the "house trailer haulers" usually have several tire/wheels they carry with them. On the triple-axle trailers, they usually pop a tire loose from the rim on sharp turns.

Just some thoughts,
CBODY67

 

[fury fan]

I've heard the 'offset burns up wheel bearings' thing in the past, but I'm not buying into that, not until someone shows me some legitimate testing data, anyway. The bearings are likely tapered rollers, and mounted in a pair on a hub, so moving the offset outward will increase load on the smaller outer one - but how much? And how much will the loading increase that vs the capacity of the bearing (which the engineers dictated to be in excess)?

In a 'proven' application like this the #1 way to fail the bearings is lube-related (dirty, contaminated, etc). Replace your bearings if they are pitted or frosted, otherwise service them lovingly with some good correct grease and they'll likely never give you a problem.

 

[fury fan]

Here's what etrailer offers....looks just like a car wheel. I will compare to my 'Ma' wheels... Edit...the mopar wheels also have a 1/2" offset.

Dexstar Conventional Steel Wheel with Offset - 15" x 6" Rim - 5 on 4-1/2 - Black Dexstar T

For those getting excited about those wheels for car use - watch the pilot hole on these, it is listed as 2.62", too small for car use. They sure look correct in the picture, though?

I can't imagine they created new tooling to make trailer-specific wheels, to look just like Mopar except for pilot, but maybe the market is there for it.

 

[73Coupe]

So I inquired to the folks at etrailer, and they replied and added it to their FAQ page (yay):

"You asked a great question, so I made an answer page for you with additional information. You can see it here:
http://www.etrailer.com/question-294144.html?fb=yes

The differences from trailer wheels, like the Dexstar Conventional Steel Wheel with Offset # AM20504 that you referenced, and vehicle wheels, like GM OEM wheels, can vary based on a lot of things.

Trailer wheels are specifically designed to be used with trailer tires. Trailer tires have sidewalls that are more stiff so that they can better handle the vertical load while vehicle tires have more flex in the sidewall to help make the ride more smooth for passengers and accommodate the movement of driving.

Not only is their construction slightly different, but the bolt patterns, widths, offsets, and weight capacities will vary as well. Trailer wheels tend to not have an offset (with the exception of a small portion of wheels) so that the load will be right above the tire which makes for better load bearing tread wear. Since the load in a vehicle varies from the load in a trailer, vehicle wheels tend to almost always have an offset.

Even if you have a trailer/vehicle wheel that matches up perfectly with the opposite of what its supposed to be used for we still recommend only installing them on what they were created for. This will ensure that you can travel safely and get the most use out of your tires and wheels.

I have attached some helpful articles on trailer tires and wheels that you can check out for more information."

expert reply by: Jon G