Gas, tires, oil.

When I went to Death Valley last spring, I got a stone bruise on one of my tires on the nasty washboard road to the Racetrack Playa (I was talking to a couple of guys I met at the Eureka sand dunes, and one of them said that he actually saw a couple bolts fall off the front of his old FJ on that road, he couldn’t find them and had to replace them with bolts from somewhere else on his truck). I got it plugged, but I didn’t trust it anymore. Rather than get a new tire, I decided to go to 16″ tires rather than the 15″ tires that were stock on 1/2 ton trucks in ‘82. The main reason is to get more load capacity: the 15″ tires only have a load range C with a weight rating of 1985 lbs. With the whole family and some camping stuff, the suburban is well over 6000 lbs., so it is very near maximum weight for the tires. And I’m pulling a double axle camper trailer. I also wanted taller tires to make up some of the difference in my axle switch (3.42 to 4.11 gears). However, lots of newer model trucks also use 16″ tires on 1/2 ton trucks. This means that some tire sizes are availible in load ranges C, D and E, which means that just going to 16″ is not sufficient. Unfortunately, I can’t use the stock rims 6 lug rims that come on newer chevy trucks because they have too much backspace and hit the tie rod on the older trucks. After lots of searching for used rims, I gave up and ordered a set of Cragar Soft 8 16″x7″ rims from Summit. Then I started seaching for tires. I wanted a set 255-85/16 tires, I had this size (Kelly Springfield MSR) on a 3/4 ton suburban in the past and really liked them. They are 33+” tall but not too wide. Calling around, everyone wanted $650+ for these tires, so I started to look for used on ebay and craigslist. One morning on my way to work I stopped by a local tire shop that sold used tires. The guy didn’t speak english, so after a bit of non-communication he went over to a tahoe parked inside the building and started beating on the side. Eventually a bleary eyed younger guy (his son) opened the door. He apologized for being so hung over and said he couldn’t get out of the truck because of an injury to his foot (I didn’t ask details). So I started looking through the used tires, coming back to roust him up to ask the prices. Eventually I found a set of 295-75/16 bfg ko’s with ok tread. A little wider and shorter than I wanted, but I got the set for $110 (plus $20 for a 265-75/16 for a spare). They fit fine with no lift.

Unfortunately my tire chains will no longer fit, so I’ll have to watch the weather if I want to go over any passes in winter. But these tires have a weight rating of 3415 lbs. so they should have a lot less sway when towing (stiffer side walls) and I’ll be able to air them down a lot more when going offroad. Of course this means having a way of re-inflating them, so I started working on converting the air conditioning compressor to an air compressor, but that’s for another post.

I’ve been wanting to do a couple led projects, but the lack of cheap leds has been holding me back. Last year, over at the Make blog, someone mentioned using led christmas lights as a source for leds. We hit some day after christmas sales and got three packs of white and one of colored led lights. The whites are going to be for interior lights for my camper trailer, but here I’m going to show how to convert a regular flashlight to led using red leds. I wanted red so that would have flashlight for camping that wouldn’t wreck my night vision (astronomers, the military, wildlife photographer all use red filters on their lights because they preserve your night vision). I was just going to use some sort of red filter, but found this idea on an amature astronomy website. The colored lights used 70 2V leds (what it specified as replacement bulbs anyway) in series (one light goes out, they all go out). 2V seemed like an odd voltage, but they were run on AC, so maybe that’s RMS. I found that they work nicely with 2 dry cells (~3 V).

The leds are in holders that plug in to sockets, you just need to straighten out the legs to remove them. Those sockets may be nice for other led projects. I happened to have a burned out flashlight bulb hanging around. I broke the glass with a pair of pliers.

Now I had to find out which of the filament holders was ground (negative), I used a multimeter. The wikipedia page on leds is a nice reference for determining the polarity of leds, but basically the negative lead is shorter and base has a flat on it. Next I trimmed leads on the leds (has to be short enough not to hit flashlight lens) and soldered them (in parallel) to the filament holders of the flashlight bulb.

They also have to fit through the hole in the flashlight reflector, 2 barely fit, but with some trimming 3 might go.

The AA batteries should run forever with these leds, and while its not terribly bright, its perfect for what I want it for: finding a keyhole or navigating inside the camper without losing my night vision (the camera makes the light look much more yellow than it is).