Gas, tires, oil.

The ac on our suburban was disconnected when we bought it and since I had no plans of ever hooking it up again I decided to remove as much of it as possible. I figured that the compressor had gone bad. But when I removed it, I realized that the compressor turned fine, it was the pulley that was locked up.

You can see above that the pulley is crooked (clutch bearing is shot). Though I still had no plans of getting the ac working, I have wanted to add onboard air to the truck. My brother had a nice rig in his jeep, he put a small 110v air compressor (the kind with a tank, that you might find in any garage) in the back. Then he plumbed the ac compressor up to the tank and wired the ac electric clutch to a pressure switch. When ever the engine was running, it would keep the tank topped off. If he was somewhere with 110v power, he could also run an extension cord to the compressor so he wouldn’t have to keep the engine idling.
I just wanted to be able to re-inflate my tires after airing them down for offroad driving. First I had to fix the clutch bearing. The book says to use special tool j9401 to pull the clutch (and j9480 to reinstall it), but of course I don’t have that tool.

The inside of the hub is threaded, I found that a 1/2″ pipe fitting would kind of thread in (I suspect that it’s actually 13/16″ like an oil filter but haven’t comfirmed it). I sawed off a 1/4″ off the end so it would screw all the way in (it was loose, and since pipe threads are tapered, the farther I could screw it in the better). Then I tack welded a 1/2″ nut to on the end. Then I screwed on to the hub and screwed in a 1/2″ bolt to pull the hub.

Here’s a pic of the tool after I got the hub off.

As you can see below, the bearing was really shot.

The new bearing was pricey, about $40, but worth it in the end. Next time I show how I got an air hose to connect to the compressor and how I controll it.

I snapped this pic in Leadfield, a ghost town in Death Valley. It needs a little work but people have started with less.

Here’s an over view of the town from the pass above it.

It’s on Titus canyon road, which is a very nice drive.

A nice example of mosaic.

Some nice narrows.

And some indian pictographs near a spring.

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.

Over the years people have used various schemes to measure the aerodynamics and parasitic drag of a vehicle using what is called a “coast down” technique. What you do is take a car up to speed, put it in neutral and let it drift. You can then use a stop watch to measure the time it takes to decelerate a certain amount (say, from 65 mph to 60 mph). Given the weight of the vehicle, you can calculate force opposing the vehicle at this speed and the horsepower needed to maintain that speed. If the measurement is done at several speeds, you can separate the rolling resistance (tires, wheel bearings, brakes dragging, etc), which is proportional to speed, from the air resistance, which is proportional to the square of velocity. Obviously, you need to find a section of road that is flat and level, and you should ideally avoid windy days, though repeating the test in opposite directions would help.
What I would like to develope is a method to record continuous deceleration data. This would allow you to fit the data and obtain much more accurate results. These sorts of results could be very interesting, for instance, you could determine the effect of various modifications on performance. Is it better to leave the tailgate up or down on a pickup, is the drag from a rooftop luggage carrier enough to make it worth removing when you are not using it, what is the change in rolling resistance with tire pressure? Now, I can think of several ways to obtain this data, first, you could use an inertia detector to directly record the deceleration. I believe there are commercial devices designed to measure acceleration performance in just this manner and I wonder if the hard drive protection inertia detector in mac laptops could be used. Another method would be to take data from the computer of a modern car through a laptop interface. One of the data channels is speed, though you would be limited by the accuracy of the speedometer. Having neither a mac nor a modern car I decided to use my GPS (a garmin 12map) and pc laptop. While gps reciever have a well known error in position, the speed seems to be very accurate. In addition, they also indicate elevation, which may be useful in finding a flat piece of road for the test.
Most GPS recievers can ouput real time data through a serial cable. Mine can do so with either a proprietary Garmin protocol (which is documented) or a standard called NMEA, which is plain text. I searched around for couple days for an interface program, but was unable to find exactly what I wanted. Plenty of programs record position, but not speed. So, I decided to just log the entire output, then pull out the data that I wanted. I used Hypertermial (comes with Windows) to connect to the gps. You need to specify Com port (com 1 for me), 8 bits and no parity and 4800 baud. If successful you will see a bunch of text scroll by on your screen. You can either cut and paste from the screen (set the buffer way up) or log the session to a file. Here is some example output:
$GPBOD,,T,,M,,*47
$GPRTE,0,1,c,*36
$GPRMC,024433,A,3958.908,N,13148.360,W,025.8,358.9,261106,015.1,E*6B
$GPRMB,A,,,,,,,,,,,,V*71
$GPGGA,024434,3658.910,N,12148.360,W,1,09,1.4,79.9,M,-28.9,M,,*4B
$GPGSA,A,3,,06,07,10,16,18,21,,26,29,30,,2.4,1.4,1.9*38
$GPGSV,3,1,11,03,00,315,00,06,63,140,49,07,67,305,47,10,07,043,38*7D
$GPGSV,3,2,11,16,26,298,43,18,58,214,38,21,63,323,46,22,20,219,00*79
$GPGSV,3,3,11,26,33,089,42,29,30,072,42,30,08,185,34,,,,*41
$PGRME,3.7,M,4.6,M,5.9,M*24
$GPGLL,3658.914,N,12148.360,W,024434,A*32
$PGRMZ,262,f,3*1D
$PGRMM,WGS 84*06
$GPBOD,,T,,M,,*47
$GPRTE,0,1,c,*36
$GPRMC,024435,A,3958.922,N,13148.360,W,024.6,358.5,261106,015.1,E*66
$GPRMB,A,,,,,,,,,,,,V*71
$GPGGA,024436,3958.923,N,13148.361,W,1,09,1.4,80.1,M,-28.9,M,,*46
$GPGSA,A,3,,06,07,10,16,18,21,,26,29,30,,2.4,1.5,1.9*39
$GPGSV,3,1,11,03,00,315,00,06,63,140,49,07,67,305,47,10,07,043,37*72
$GPGSV,3,2,11,16,26,298,43,18,58,214,38,21,63,323,46,22,20,219,00*79
$GPGSV,3,3,11,26,33,089,42,29,30,072,42,30,08,185,34,,,,*41
$PGRME,3.9,M,5.0,M,6.3,M*24
$GPGLL,3958.927,N,13148.361,W,024436,A*31
$PGRMZ,262,f,3*1D
$PGRMM,WGS 84*06
The data we want is in $GPRMC (GPRMC = global positioning recommended minium navigation information). Next time, I’ll show a Perl script that I wrote to pluck out the time and speed, and an example calculation. But here is a little preview just to show that this might work (i.e. data is recorded at a rate sufficient to fit):

I recorded this with my suburban on the road outside my house (you can see effect of couple small hills near the end coast down section and a car was coming up behind me so I didn’t come to a complete stop), but even at 40 mph you can see the effect of air resistance (the speed falls much faster per second at 40 than at 10 mph), but of course the suburban has the aerodynamics of a brick.

The 14 bolt semi-float axle that I bought for my suburban had recently been in a ‘70 chevy pickup (it was originally out of an ‘88) and the distance between spring perches was not right for the ‘82 suburban. So, first I pulled out the stock 10 bolt rear and put it next to the 14 bolt for comparison.

Next I ground off the welds with a 4 1/2″ angle grinder and knocked off the perches with a hammer. Then I cleaned them up and champhered the edge in preparation for re-welding them.

I needed to be able to measure the center to center distance of the perches, but the differential prevents you from being able to just measure them with a tape measure. So what I did is use a set of outside calipers to measure the width of the center section.

Then I could use a set of inside calipers to set the distance from the perches to the center section.

I also needed to set the angle. I the angle between the perches the the yoke with a magnetic protractor, setting it to be the same as the stock 10 bolt.

Then it was just welding them on.

Another ad from the April 1960 Car Life magazine.

Now go google “chassis research” and check out the history of this company (nitrogeezers is probably a good starting point).

Not only did the awful washboard road in Death Valley cause me to lose a power steering line, the exhaust system and a tire on my ‘82 diesel suburban, but when I went to open the rear door, the button pushed in and fell inside the door. To get the spare out, my wife had to crawl in the back and drag it over our luggage. Later back at camp, I used my makita to take off the door panel and retrieve the push button.

Back at home, I pulled the handle off and discovered the problem, a little diecast potmetal tab had broken. It retains the return spring and centers the rod that extends from the back of the button. The spring and broken piece are shown below the handle:

I rigged up a replacement with plumber’s tape (the metal equivilent of duct tape). If you don’t know, it’s a roll of sheet metal that has a series of pre-punched holes and is used to make pipe hangers and such. A little forming with pliers and a couple pop rivets and it’s done:

While I had the door apart, I wanted to add an interior door lock and latch. Stock, the only way to lock the rear doors is from the outside with a key, the only way to open the door is with exterior handle. This is not ideal, when locking the vehicle, you can just push down all the door locks in the front, but you need the key for the rear doors. We also occasionally sleep in the back when camping and you can’t get out the back, you have to crawl over the front seats. I’ve also had the rear doors swing closed while I was in the back getting something, again having to crawl out the front (a problem if the back is piled high with stuff). While the handle was off I saw how the latch and lock works. The rod on the button pushes against a plate that opens the latch. The lock works by lowering the plate so that the rod passes over it. So, first I determined that the little pull things on for door locks use #10-24 screw threads (at least older gm cars and trucks). Therefore I used some #10-24 all-thread (or “ready-rod”, continuously threaded rod) to make the lock (and latch) pull.

To make the latch pull, I just drilled a hole in the door and the latch plate. I used a nylock nut on the end. While the button on the outside of the door pushes, this interior latch just pulls. The lock knob attaches to the latch by the way of a coupling nut that I cross drilled with a clearance hole (see above). Then it was just a matter of screwing on some lock pulls.

I could have used a more traditional door handle, but this was simple and unobtrusive. It sits nearly flush, so it isn’t likely to interfer cargo.

In case you don’t know, turducken is a dish where you stuff a turkey with a duck, stuffed with a chicken. The rather unprepossesing vehicle below is an IHC Loadstar 1700 moving van that I bought at auction for a couple hundred bucks about 10 years ago.

But it’s what’s inside that is interesting.

My chopped ‘52 chevy pickup, which itself contains another International Harvester: a 1962 Cub Cadet.

And a ton of GTO parts.

I couldn’t help but post this also, it’s an ad from the magazine the Bonneville article (below) came from (October 1937 Automobile Trade Journal). Check out the windshield, the roof doesn’t even need to be chopped.

Click image for larger view.
Do any of these exist today? Googling didn’t turn any up right away, but I did find this 1938 4 door ex-forestry fire truck (what a great tow vehicle). A company apparently makes a model of the streamlined moving van pictured above. I wonder how hard it would be to make one from scratch…I mean, lots people make little teardrop campers. The sides on this are flat, you could use aluminum or fiberglass over foam. Maybe use a 1-ton 4x4 truck chassis and a straight 4 or 6 turbo diesel, an nv4500 5 spd and ranger splitter. You’d have a great camper/tow vehicle. I love the semi-coe look, not a true cab-over where you lose the streamlining and style, but a shorter hood than a regular truck.

Coop recently posted some scans of some early post-war salt flat racing, so I thought I’d show a little pre-war stuff. Below is a two page article from the October 1937 Automobile Trade Journal about David “Ab” Jenkins and his car Duesenberg designed car, the Mormon Meteor II. Do yourself a favor and google up some more info this guy. You can click on the images below to get a large enough version to read the text.