Saturday, September 22, 2007

My Personal Truck

My personal vehicle is a truck. It is a 2003 Chevy Silverado Z71 (its a 1500, but they don't label the Z71 as a 1500 any more.. not sure why).

Why do I drive a truck? Well, I couldn't do a LOT of things if I didn't have a truck. Trucks are cool. Trucks can do more than any other vehicle. Trucks are meant to be used. Trucks are powerful. 4 wheel drive trucks, when set up properly, can go through just about anything. Trucks are big (safe on the road).





OK, so trucks are cool and they can do more than any other vehicle. Right. Do I actually use my truck?

Yes, I do use my truck.

If you are going to get a truck and baby it then fine, have at it. However, you are not using and appreciating the vehicle in the manner in which it was designed.

Construction on my Dad's house



Loaded up for Canada trip summer 07' No, its not full yet.


Set up and operating in the 07' ARRL September VHF contest. If you haven't seen my posts about operating my radios in Canada and my Portable Rotatable Mast, then check those out. This is an extension on the mast idea - only, its mounted in the back of my truck. The upper mast is 3 sections, telescoping, so it is collapsed going down the road - but all the antennas are installed. This makes set up a matter of a couple minutes and I'm on the air. Everything is as hooked up and ready as it can be to minimize set up time.


My truck isn't just a tool and transportation. I value it more than a lot of things. It is my freedom to go where I want and to do what I want to do. I work on my truck myself. I take it to the dealer for routine maintenance (oil changes, break service, ect). However, all the extras I do myself - lifting, suspension adjustment, exterior accessories, electronics (radio equipment, wiring, lights).

As soon as I got this truck I was making plans for it. I have always wanted a truck with a lift and big tires. So, that's what I'm working on. It is a SIGNIFICANT expense to do so, however. I am doing what I can when I can and it makes sense.

The first thing I ever did was put the body lift on. It is a 3" Performance Accessories kit. Basically, what the kit does is it lifts everything mounted to the frame except the engine, gas tank, transmission, drive train, etc, off the frame. That leaves the bumpers and body pieces. Piece of cake, right? Nope.

I knew what I was getting in to when I got the lift. I had researched it before hand and made sure it was something that I could handle with the help of a few grease-monkey friends. It was an ALL day project.

The bumpers were lifted with brackets and the body pieces (cab, bed) were lifted with blocks. Ground straps had extensions added to them, the steering shaft had an extension put in, the bumpers had to be modified (cut) to accept the lifting brackets, and the fuel fill tube had to be extended.

My friends and I did everything in front first, then worked our way back. Lifting the body off the frame was an interesting feat. We used two floor jacks and lifted up one side, put the blocks and bolts in, then lifted the other side and did the same thing.

The hardest part about the lift was the time and effort it took. We forgot to hook up one ground strap on the back of the engine (towards the firewall) and the engine didn't start when it was all done. We checked all the grounds and connections and found the unconnected strap, put it back on, and the truck has been fine since.

The body lift really adds to the stance of the truck. It has the right proportions now. The stock truck sits too low, in my view. The other issue with stock trucks is the front end is always riding on the ground. New trucks don't have this problem, but as the truck ages the front sags. This is due to the torsion bar suspension in front. To fix this, you crank down on the torsion bar adjustment screws. Where the torsion bars connect to the frame (under the center of the cab) there is a piece called a "key". This is basically like a giant wrench for the torsion bar. There is a set-screw on the bottom of the bracket that this all mounts to that pushes up against the key. The further this is cranked the tighter it makes the bars, thus the higher the front sits.

Note: don't tighten bars too much or the front will sit higher than the back. That's not cool. The bigger issue, though, is the shock absorbers. You can NOT use this method to "lift" the truck, it is merely to level out the front and rear. The shock absorbers can only take so much travel. If you crank the bars too much the normal ride height may be right at the lower limit of the travel. That means the weight of the truck is twisting the torsion bars just enough to keep the pressure off the shock absorbers. When the weight is taken off of the torsion bars (IE, when lifted with a jack, off-roading) the strength of the torsion bars can RIP the shocks apart. The two halves will literally be yanked apart. That's not good. So, why not change the shocks out with longer ones? This brings up another issue - the angle of the CV's. Too steep of an angle and you put a lot of stress on the bearings and drive train as a whole. That's also not good. It is better to get a lift and drop the whole drive train than increase your angles. Its more expensive, but it is the RIGHT way to do it.

I do just enough to balance the front and rear. This, however, causes the front to be real high when I load the truck down - either weight in the bed or pulling a trailer. I think its a small price to pay for a cool, balanced looking daily ride.

The tires on the truck are Bridgestone Dueller Revo's, 285/75-R16 (33"). Stock tires are 265/75-R16 (30"). I got the bigger tire because I want a bigger tire! The only issue is the wheels are a tad narrow for them, but it really isn't a problem. I have never noticed any ill-affects from that.

I had a heck of a time picking out tires. For one, I wanted an aggressive tread. I wanted something that was going to be really good in the mud and snow. I was originally looking at the BFG Mud Terrains. A buddy of mine had these on his Jeep Cherokee and they wore down too fast and were loud going down the road. So, I decided against these. The reviews on Bridgestone's duellers were great online so I looked in to them further. I was also looking at some Firestones. I had Firestone wilderness AT's on the truck and they were crap. They were quiet, rode real nice on the highway, and gas mileage was great. However, that's all on dry pavement. Get them wet and they spin like no other. Get them on ice and snow and you do donuts in intersections. The first winter I went through with the truck I had to run in AutoTRAC or 4 wheel drive so I could keep the back end on the road. 2 wheel drive was hairy. That is why I got new tires! So, I figured I would go with Bridgestone and try them instead.

The Dueller Revo's are excellent tires. I would recommend them to anyone with a 4 wheel drive. They are quiet on the road (amazingly), they are good in mud (Ive never been stuck in mud with them), and they wear really nice on the road. I have at least 40,000 miles on mine and they have PLENTY of tread on them. They are rated for 50,000 miles, but I bet I can get double that on them. One great design aspect of these tires is the pointy tread design. If you look them up online you'll see that the blocks aren't square rectangular. The blocks taper around the tire. These points cut through water on the road to prevent hydroplaning (an issue I had with the Firestone Wilderness AT's, really bad too). They also keep the hammering of the blocks on the road down - this makes them quiet. The blocks hit the pavement gradually due to the taper. Now, they are still noisier than a street tire.. but compared to any other all-terrain tire, they ROCK!

Other additions for the future:

I want a Cognito 7-9" kit. From what I have found it is the best engineered kit available. I will keep it at the 7" level as I don't want to put too much of an angle on my drive shaft (too much of an angle and you wear out the bearing in the transfer case and put lots of resistance on the drive line). Plus, the 3" body lift is 3" I already have. The majority of the "ground clearance" comes from the size of the tires, not the suspension lift.

Another idea I should address is the difference between "ride height" and "ground clearance". A body lift does not increase "ground clearance". It makes you sit up higher. The purpose of a body lift is extra clearance for larger tires. The tires are what add to the ground clearance. With the 3" body lift and the 33" tires over the 30" stock I get a total of 4-1/2" more "ride height", yet only an inch and a half of "ground clearance". See how that works?

Now.. a suspension lift is a little different. You can argue that it increases the ground clearance. It does to a certain extent, but not entirely. There are items that hang down from the frame that you must consider - the drive shaft being one and the front torsion bars (unless you go to a straight axle conversion). As the distance of the rear axle increases from the frame the steeper the angle of the drive shaft. It is always going to be there. The torsion bars are the same way, only the angle of these has to remain relatively the same. The torsion bars need to be perpendicular to the swing direction of the A-arms. Therefore, they must be dropped when lifting. They will always be hanging down. If you are in to off-roading and want the most capability out of your vehicle, watch out. Everything that hangs down is something that will hang up on the terrain.

So if lifting doesn't increase the ground clearance properly, what's the point? The purpose of lift kits is to increase suspension travel and increase clearance for larger tires. The larger the tire the more distance between the outside of the tire and the axle, or radius. Take the radius of the tire you want to put on and subtract the radius of the tire you currently have (in my case the diameter is 33" now, 30" before with the stock tires. That's 16.5" radius minus a 15" radius, and you have the increase in ride height and ground clearance. In my case an inch and a half.

The tires I want are 38" Super Swamper TSL's or 37" Parnelli Jones Dirt Grips. I haven't decided which. Maybe I'll have a couple sets. The PJ's will be great on the road and the Swampers will be good for the mud. These tires will require a 10" wide rim, however. Another set of items Ill need.

When putting bigger tires on a vehicle you have to consider the drive train. It is an absolute must. The standard gear ratio is too high for the 38" tires. It would be like starting a manual car in second gear instead of first. So, I need to change the gear ratio.

When changing the gear ratio you are putting more power to the wheels. As the tire size increases so does the torq needed to rotate it. When off-roading you put yourself in situations where the wheels need a lot more torq to get the vehicle moving. The tires grip the terrain and pull the weight of the vehicle along. Think of climbing a rock wall compared to walking down the side walk. What is harder to do?

Because of the torq issue, the stock axle isn't strong enough to take the load. Going down the road it would be fine. It would be under more stress than a non-lifted, non-big tire truck but it wouldn't be a big problem - the stock truck is rated at 7800lbs towing capacity with 3.73's, 8800lbs with 4.10's. I think the axle can take a few more inches of tire. The problem starts when you stop the tire. If you are crawling up a hill over rocks or logs then you are going to stop the tire. It takes a lot of force to get the tire to climb up over an object, rather than just rolling.

So, to help on the strength, the axle should be swapped out for a GM 14 bolt. The stock axle is a 10 bolt. This will give me more strength for more assurance against breakage. The axle swap won't be a direct bolt-in replacement. The spring mounts will need to be re-done on the 14 bolt to get it to mate with the spring locations on the 1500 frame. Not a big deal, just a little more work. Also, Ill need to get some 6-lug axle shafts. I forget if you can get 6-lugs on a 14 bolt. I know they come in 8-lugs though, the 14 bolt is used on GM's heavier trucks - 2500's and there is another version of the 14 bolt used on the 2500HD's and 3500's.

Along with the rear axle I'll need a locker. What a locker does is lock the two axle halves together. If you watch a vehicle make a tight turn you'll notice the outer wheel spins faster than the inner wheel. That is because the outer wheel has more distance to cover in the same amount of time. The "differential" in the axle allows this to happen. It is a gear system that has one large ring gear attached to a housing that holds smaller gears (one on the ends of the axle shafts and a set on opposite ends connecting the two shafts). If you jack the vehicle off the ground and spin one wheel with your hand, the other wheel spins in the OPPOSITE direction. This is because of the smaller gears. A locker takes the place of the differential. Actually, a locker is a type of differential. The difference is it is designed to either manually or automatically (my stock axle has an automatic locker) lock the small gears in place. So, the same vehicle that is jacked up off the ground would have both wheels spin in the same direction when you spin one. Only, you would be turning the drive train as well. This is a must when off-roading. If you don't have a locker then when one wheel is in the mud spinning it takes all the power out of the drive system. The power takes the path of least resistance. When you lock the axle shafts together they act as one. Therefore, if one wheel has no traction it takes NO power. All the power goes to the wheel WITH traction and you are able to move.

The front end needs to be protected more. The truck has skid plates on it (part of the stock Z71 off road package). However, the skid plates are only on the underneath side of the frame. When transferring from flat ground to climbing hills (or the other way around) the front end can touch the ground. Therefore a heavy duty bumper and skid plate should be used to help lift the truck up any tough spots.

Getting stuck in the mud isn't fun. I have gone on rescue missions to extract some of my friends who were not so smart. Having a way out is really nice to have. If your buddies are already a mile down the trail then having a means of getting yourself out is handy. Or, if you really screw up and put yourself in such a bad position that no one can get NEAR you (I saw this once, we couldn't even walk within 50' of the blazer).. a way to get out yourself is a good thing. Electric winches to the rescue! The one I am looking at is the Ramsey Patriot 9500 or 12000. I want something strong enough to pull the truck, and whatever gear is in it, through the toughest spots.

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