Visit our Popular Forums

fitzjo1 · 12-29-2010, 07:01 PM

The old Lunar Schooner was long overdue for axles, wheels and tires. Being a compulsive optimizer, I set about researching all my options. Thanks to this (and other) forums, there was plenty of good reading.

If I lived near Inland RV, I would have probably let Andy take care of this project for me. I'm a busy guy, and I feel sure they know more about this procedure than I do. Unfortunately, I'm about 2400 miles away. I don't know of a dealer within a few hours drive with any real experience doing this type of work. So, I felt like it would be best if I did it myself.

So, let's start with the axles. After doing a lot of research, I will have to agree with Andy that price comparisons between a #10 Dexter and a heavier-duty alternative is not exactly fair. The #10s appear to have smaller bearings, and definitely have smaller brakes. You can order a modified (derated) #11. It will have bigger bearings, spindles, brakes, and a bigger tube than the #10. Why, it will just be...bigger. It will also cost more. I don't know the exact numbers. But, let's just say that the difference will be less than between the Henschen and #10 Dexter. If you're a firm believer that bigger is better (and it usually is), you might want to get Henschens or a #11.

However, I had some really good discussions with a very nice gentleman in the Dexter Engineering department. While he was more than happy to try to accommodate requests from Airstreamers, and he had no arguments against the "bigger is better" contingent, it became apparent to me that the #10s weren't exactly underdesigned. In the end, I decided I was OK with the #10s.

Another factor that tipped me toward the #10s was that the #11s might be overbuilt for what I wanted. For starters, I didn't want to push up my weight ratings, and there's a limit to how low they can go with a #11. I want a smoother/softer ride. I have weighed my camper. It does not have anywhere close to 6000 pounds on the wheels. Even the GVW isn't close to 6000 lbs--even when my wife packs

. I decided to order 2800 pound axles. But, based on a recommended load of ~80% of the axle's rating, an argument could be made for going lighter than that. I am convinced that the bearings (which are not the NeverLube type) and spindles will last plenty long enough for my purposes. Having lighter parts will also reduce unsprung weight in the suspension.

As for brakes...well, let's just say that my main complaint in the past has been that they locked up too easily. Maybe I'll change my tune after road testing the new/smaller brakes with those nice, wide LT225 75R16 tires.

Another significant factor for me was freight. Remember the 2400 miles? It added up to a lot of freight. Dexter is much closer to me. Freight for a pair of #10s, shipped to my driveway, was only ~$130.

I ordered my axles less than two weeks before Christmas, and they arrived exactly two weeks later. Everything looked fine, and the nice Fedex man rolled them right over to my camper.

The only complaint I have so far is that the brackets were made 1/8" closer together than what I ordered. However, after reflecting on this, I realized that this may be a result of how they must tolerance the dimensions. If the actual (maximum) space is 57-7/8", anything over that is BIG trouble. If their tolerance is +/- 1/8", the nominal would have to be 57-3/4" in order to allow for the tolerance. I don't know their tolerances, and one might feel that 1/8" is too much. But, in any case, better to be too narrow than too wide. I picked up a piece of 16 gage sheet steel for shimming the brackets.

Anyhow, the wife is getting impatient, and I have to go for now (I did spend most of the day grubbing around in the driveway after all). When time allows, I will add info on the wheels and tires.

DanielB · 12-29-2010, 07:05 PM

fyi,
Don Mar RV Sales
Authorized Airstream Sales and Parts
Phone: 803-453-5011 or 800-581-4678
Fax: 803-453-5001
email: mary.donmarrv@yahoo.com
265 Pudding Swamp Road
Lynchburg, SC 29080
Exit 141 on I95

fitzjo1 · 12-30-2010, 11:24 AM

Thanks for the heads-up on DonMar. I visited there about 10 years back. I had heard from more than one person that they were closed. Apparently, this was incorrect. Too late for me. But, maybe it will be a help to someone else.

cmgirdwood · 12-30-2010, 11:36 AM

we did the axels/wheels/brakes last spring on our 72 overlander and believe it or not it went pretty smoothly using the ramp method. the most important step is the spraying with jb80 2 weeks prior to beginning and keeping it up until you can actually move the nuts. of course there is always surprises and this proved no exception as chris had to rerivet the belly pan but that was it. we did it in one day believe it or not and the new wheels look oh so spiffy.
mareinalabama now not mn

fitzjo1 · 12-30-2010, 12:02 PM

Having sorted out my axle choice, the next step was to choose some tires. I made up my mind pretty early on that I would not be buying ST tires. Many claim they have tougher sidewalls. Others claim they give a smoother ride. It seemed to me that both could not be true. What I knew for sure was that ST tires tend to be rated for only 65 mph, and they are not rated for use on passenger-carrying vehicles.

I don't know much about tires, but I do have an engineering and testing background. Brand X might be able to carry their rated load at 65mph while on roads nearly hot enough to cook eggs, but I'm not counting on it. If brand X decides to make their product better than the standards require, it will cost more. If they made that choice, I'd think they would be smart enough to tell the consumer. Otherwise, many consumers won't buy it, and rightly so, since there will be no obvious difference to justify the added cost.

On the other hand, a typical LT tire is rated for much higher speeds and is not exempt from the government-mandated tire rating system (which includes a temperature rating). And, here's the other thing. If a particular model of LT tire is failing in significant numbers, there will be a lot more attention paid to the problem. So, if nothing else, there's a lot more pressure to keep manufacturers focused on quality.

Once I started looking for LT tires, I noticed something interesting. There's a product gap between passenger tires and LT tires with lettered load ratings. For example, almost nobody makes an LT225 75R15. Guess what fills in this gap? ST tires. So, there seems to be some truth to the story that they're made to carry loads not otherwise possible on tires of their size. Anyhow, it became apparent that if I wanted LT tires, I would need to go up to a 16" wheel.

So, the big question became: would the bigger tires fit?

Once again, I did lots of reading and measuring. On paper, the LT225 75R16 was only about 1/2" taller than my old bias ply 7x15s, and about 1/2" wider. But, a picture's worth a 1000 words:
Axles3.JPG
The tire on the right is the new 16" radial. It's actually a little SHORTER than the old bias ply tire. But, take a look at the tread. It's a lot wider and flatter. I'm betting this tire will hold the road a lot better.

Anyhow, I got the tires from Tire Rack. They have a great tool that lets you compare tires using buyer reviews. The ratings include the number of user miles behind the ratings. So, it's easy to make sure that a good rating isn't just a fluke being driven by a small sample size. I deliberately picked a tire with many millions of miles of user data.

The other benefit of a popular tire is that it's easy to get "fresh" ones. Mine were made in late October 2010.

The tires arrived the day after I ordered them. You can have them shipped directly to wherever you're getting them installed. But, I wanted to inspect both tires and wheels before doing anything with them.

Anyhow, I have to go again. I will post a side-by-side photo of the old and new wheels/tires later (it's on my daughter's camera). But, the tires fit on my 68 Overlander fine when paired with the right wheels. More on that later.

fitzjo1 · 01-10-2011, 03:09 PM

Once I had sorted out the tires, all that was left was to pick some wheels. The aluminum wheels were tempting, but I found some nice looking steel wheels.

The photo shows the old and new together. It also gives some sense of the height difference achieved by changing axles. The photo was taken with jacks holding the camper up so that the new wheel was just touching the ground. Of course, the new axle has a 32 degree down angle.

I got the wheels from Southwest Wheels. You can see the one I used at this link: http://www.southwestwheel.com/store/...w128700ms.aspx They are 16"x6". The folks at Southwest seem to have lots of stuff in stock. The wheels arrived two days after I ordered them.

fitzjo1 · 01-10-2011, 03:24 PM

I didn't have these photos handy when I made the axle post. But, I thought someone might find them useful. You can see both sides of the same bracket and how the bolt holes differ.

If you look carefully at the first photo, you can see that the axle tube is a tiny bit smaller than the opening in the flange. I chose to align against the back of the opening, since any horizontal forces generated by the wheels will always be in that direction. Notice that my unit has a small flare at the opening to accommodate the welds on the axle bracket. Others have commented that this feature was not present on their camper.

Using the opening for alignment, I checked to see if the wheels were equidistant from the hitch. They measured identically. Thank goodness for the occasional detail that goes your way!

FWIW, I think the alignment of the two axles relative to one another could be more critical to tire wear. It's not like I want my trailer to go down the road dog-legged. But, it actually did do this with the old axles--though only slightly. It had no noticeable effect on tire wear.

I'm still looking for a satisfactory grommet for the brake wires. Everything seems to be made for a thinner section than I have. If I find something nice, I'll post it.

funkill · 01-10-2011, 03:24 PM

Thanks for all the details fitzjo1. When I'm finally ready to bite the bullet and replace my Marathons, I will probably make a similar choice in wheels/tires. Your info will be very helpful. You choose some nice looking wheels!

Thankfully, my axle job is behind me... though I chose the Henschens

.

Cheers,
Laura