What to Do?? Tired, Again!

Tires have always been an important consideration for RVs, and perhaps even more so for tires on heavily loaded single axle trailers. We'd only had the Scamp for six months when I installed a set of Maxxis UE-168 light truck tires to increase the safety margin. By the time we headed to Alaska, we were already running into availability issues.

On our return from our Alaska trip, I switched to 15" rims with Continental Vanco 215/70R15 tires that have provided excellent service for nearly five years, but once again, my tire of choice is no longer available! Apparently, Westfalia owners have switched to 16 inch rims to get higher capacity tires, reducing the marketplace for the specific size I need.

Since we continue to have tire diameter limitations due to our garage door clearance, I was only able to locate one tire that had nearly the same load capacity as the Continental's and the same outside diameter.

We ended up going back to the 14" wheels, and for the first time, I actually bought Trailer Service tires instead of Light Truck tires, because it was all I could find.

For a number of years, Goodyear had a terrible (and well deserved) reputation for their Marathon ST tires. Made in China, they had a bad habit of unexpected blowouts.

Goodyear quit making the Marathon and introduced a new design, the Endurance, for the trailer market. They make them in the US. They've been out for a couple years and have very positive feedback.

The best combination of load and tire diameter (for our situation) was to go back to the 14" wheels which gave us a tire with 2200 pound design capacity. We could have gotten more capacity with the 15" wheel but we would have lost our ability to garage the trailer at home.

We're all set, with three new tires, and the wheel bearings inspected and repacked. Here's hoping our experience with the Goodyear Endurance is as good as it was with the Continental Vanco.

When You've Gotta Go

When we were in the Northwest this summer we suffered some equipment degradation. Still had half a handle for the all important black tank drain valve, and a pair of vice-grips in the tool box in case the second half of the handle failed. It was clear that I would have a maintenance project when we got home.

Knowing what I was facing, we did an especially good job of flushing and cleaning the tank before we left our full hookup site the day before we got home, and then put the toilet off limits.

It really was a simple, 15 minute job, made much easier because unlike Nina, I didn't have neighbors watching my every move. (Seriously, check out Nina's seriously funny post from a couple years ago.) One bolt was a bit challenging to access, but not a big deal. The new valve has an aluminum handle. Seems much less likely that part of it will break off.

Wheel Bearing Inspection

Fair warning - this post is loooong and and even more boring than usual unless you're one of a small handful trying to decide if they want to tackle inspecting and packing their own wheel bearings. Keep in mind that this is based on a 2010 Scamp 19.  Others will be similar but may differ in the details.

The first step is to securely support the trailer with the wheels off of the ground. Place the jackstands under the frame, not under the axle.

You could remove the wheels and tires first, but I elected to keep the wheels and tires mounted to the hub, so the next step for me was to remove the dust cap from the hub. The dust cap is an interference fit with the hub. I used a scraper between the hub and flange of the dust cap to start the removal.

Once the dust cap removal was started, I could fit my small rolling wedge bar behind the flange to complete the removal of the dust cap.

As near as I know, these bearings had never been inspected. The cotter pin on the street side wheel was bent in such a manner that the end of it was rubbing on the rubber plug on the end of the dust cap, shaving off slivers of rubber from the Zerk access plug. Remove the cotter pin and castellated nut and then slide the wheel off the shaft.

I always plan on not reusing the inner seal - the gold colored ring in the center of the picture. Now is the time to inspect the brake drum for undue wear.

I use the punch end of the rolling wedge bar to remove the seal. It usually takes three or four punch & pry cycles to get it out. Others will advocate driving it out by pressing out the rear bearing from the inside, but that runs the risk of damaging the bearing so I'm comfortable with automatically replacing the seal with a new one.

As you can see, the cotter pin doesn't come out nicely on the Al-Ko 3500 lb. Ultrulube spindle. The hole for the cotter pin is drilled off center to leave clearance for the Zerk fitting and grease galley in the center of the spindle, creating interference between the cotter pin and the nut castellations.

While cleaning the parts, carefully inspected the bearing for any chipping, pitting, flat spots, or discoloration of the bearing rollers or deformation of the bearing cage.

Keep the parts for each wheel together since the bearings theoretically develop a wear pattern matching with their outer race.

To hand pack the bearings, put a glob of appropriate grease (Al-Ko calls for a NLGI Grade 2 lithium based grease) in your least dominate hand.

Holding the bearing cone with the smaller diameter up, press the cone into the edge of the glob (there's that technical term again) of grease, continuing the process until grease extrudes from the top of the bearing. Turn the bearing assembly slightly and repeat. Continue until the entire bearing cone has clean grease coming out between the inner race and the bearing cage.

Clean all of the old grease out of the hub assembly.

Assuming the bearing cone and outer cup look good and you've carefully repacked the bearing, place the rear (larger) bearing into the hub and install a new grease seal. I use a soft block of wood and a hammer to press the grease seal in place without deforming it.

Clean all the old grease off of the wheel spindle. Use this opportunity to inspect the brake shoes, springs, and magnet for excess wear. Wipe a very slight amount of grease on the lip of the grease seal before carefully putting the hub (and wheel in my case) assembly back on the spindle. Install the front bearing, washer, and nut.

Tightening the castellated wheel retaining nut correctly is critical. Too tight and the bearings will overheat. Too loose and the bearings will wear out from too much side play. The Al-Ko manual (page 23) has specific instructions although most experienced mechanics do it by feel. In spite of the manual, install the cotter pin so that it does NOT go over the end of the spindle.

The last step is to reinstall the dust cap. Since the rubber plugs in the original dust caps were badly checked, I installed new caps and plugs. Once again, the block of soft wood came in handy.

I got all the parts from Etrailer.com. The #84 spindle is very common and parts are readily available.



Just as when the trailer was new, check the hubs for excessive heat at your first stop after servicing the bearings.

Update April 1, 2013: there has been discussion about the advantage of high quality American made bearings. It takes a bit of searching, but larger, easy to pack, cool running bearings are available but will require modification to fit to current production wheels.