Question: I see a lot of trucks with the left-rear shock mounted behind the axle, and the right-rear shock in front of the axle. What's the advantage of this apparently asymmetric arrangement?
Brian Dunning
Laguna Niguel, CA
Editor: I believe that it was Chevy that first made this a popular item. The axle by design wants to pull the pinion snout upward during acceleration and downward during braking. The housing will actually move enough to cause each spring to flex in opposite directions on either side of the housing. The spring, as it bends, builds up a tremendous amount of tension and then releases suddenly. This is often referred to as "spring wrap up." This in turn causes the axle to actually "hop" up and down resulting in uneven traction and can even lead to breaking parts such as spider gears, axleshafts, and teeth on the ring-and-pinion gears.
By exerting force on opposite sides of the axlehousing, one shock works in compression while the other works in extension. While it may not completely eliminate spring wrap up, it goes a long way to prevent it in most situations.
Question: I'm planning a buildup of a '74-'91 K5 (don't have the truck yet). I plan on using a 4-inch shackle flip and 2.5-inch springs in the rear and 6-inch springs in the front. I already have a 14-bolt rear with 4.56 gears and a Detroit Locker, and a Dana 60 front with the same gears and a Dana Tractech. They're military axles that I got for a good price with low miles. I plan on running either 39.5x18 Boggers or 39.5x15 TSLs with plenty of fender trimming.
First of all, are there any glaring flaws with this plan that I'm missing, like not being able to fit the tires? Also, will there be a significant difference between the Boggers and the TSLs because of the width in terms of performance and whether they will fit or not? At 6 to 6.5 inches of lift, will driveline modifications be necessary? I'm a high school student on a tight budget. Should I upgrade to aftermarket axleshafts and U-joints before I even consider wheeling 39.5-inch tires?
And last, are the gears numerically high enough for now? I plan on swapping them out at a later date but like I said, I'm on a tight budget. It has to run about 40 miles on asphalt to wheeling spots and I'm going to have to keep the stock engine which will probably be a TBI 350 if I can manage it. I know that you're probably going to tell me to go with a smaller lift and smaller tires, but I'll soon be a college student on an even tighter budget, so I'd like a rig that I can upgrade as I wheel and not have to buy major components over again like the springs, tires before they're worn, and so on.
Mike Dannenberg
via fourwheeler.com
Editor: Sounds to me like you have a great plan. Unlike a lot of people, you have done some thinking ahead of time. That's a lot of tire, but it should fit with the fender trimming. I sure in heck wouldn't go any larger. I would recommend that you go with the TSLs over the Boggers. While the Boggers work great for what they are designed for, they are not one of Interco's better highway driving tires. They are noisy, wear uneven, and don't handle all that well.
If you plan to take the truck to college with you, I think that the gearing will be just about perfect as it will keep the overall engine speed down to a reasonable level for the best fuel mileage. Speaking of that, don't expect any more than about 10 mpg.
As for going with aftermarket axles and U-joints, probably not a bad idea, but they are pretty darn expensive. The stock pieces are certainly capable of handling most four-wheeling if you drive with your mind and not with your right foot. For instance, axle U-joints lose strength the tighter the angle they work at (actually this is true with any U-joint), so just don't jump on the throttle hard when the wheels are turned to full lock.
As to changing the driveshafts, hopefully you got the matching driveshafts at the same time you got the axles. For sure the rear shaft will have to be shortened due to the shorter wheelbase. Most likely the front shaft will have to be lengthened some. To find the proper driveshaft length, I like to just use the one main spring leaf to hold the axle in place. Let the axle totally compress against the bumpstop and then measure from the center of the pinion yoke to the center of the transfer-case yoke. Then jack up the truck by the bumper and let the suspension totally drop so that the wheels are off the ground. Put some jackstands under the frame and again crawl under the truck and measure between the two yokes. Now you know what the extended and collapsed driveshaft lengths are supposed to be. Yes, it's a lot of work but you know for sure the correct length. This also gives you a chance to see if you have enough clearance for the tires as well as figuring proper shock and brake line lengths.
Question: Going through my magazine collection recently, I noticed the coverage of the 2002 Top Truck Challenge. The portion that again caught my attention was that of the '78 International Scout owned by Abelardo "Abba" Ramirez, nicknamed Terra Cotta.
The interest is due to my own '77 Binder and its rust/clearance issues. I have been looking for cut-out extended flares for nearly 7 years. When I first read the article I realized that they were exactly what I'd been searching for.
The dilemma is that the article does not indicate for which vehicle they were originally made. After considerable research among flare manufacturers, the nearest I can figure is that they are off a '70-something fullsize Chevy pickup.
I've made several attempts to track down the owner via the white pages and have been unsuccessful. If you could help I would be very grateful, either by telling me exactly which flare they are, or better yet, putting me in contact with the owner. Either of these could save me from purchasing the wrong parts. Scouts, as I am sure you are well aware, are not very easy to find parts for, especially for modification.
Shannon H. Hicks
via fourwheeler.com
Editor: Sorry can't help you with a phone number or address and it's not our policy to pass on that information. However, if I remember right, those looked like the Scout flares that are available from Bushwacker (www.bushwacker.com). Now a long, long time ago I used some Bushwacker early Chevy Blazer cut-out type flares on an IH pickup. They actually fit pretty darn good in that they were never designed for that truck. Would they fit on your Scout? I have no idea.