January 2005 4x4 Tech Questions - TechlinePosted in How To: Tech Qa on January 1, 2005 0) (
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Question: Is there a company that can help me put disc brakes on a Chevy 1-ton rearend?
Answer: Several companies offer kits to do this. They include: TSM (Dept. FW, 4321 Willow Creek Rd., Castle Rock, CO 80104, 303/688-6882); Desert Fab Motor Sports (Dept. FW, 564 N. Idaho, No. 4, Apache Junction, AZ 85219, 480/980-2681, www.desertfab.com); and Off Road Unlimited (Dept. FW, 2102 Kenmere Ave., Burbank, CA 91504, 818/563-1208, www.offroadunlimited.com).
Question: I own a '94 GMC Jimmy and love it to pieces. However, I've replaced four fuel pumps and now it needs another one. Do you have any suggestions other than a bad ground?
Dover, New Hampshire
Answer: I had to kind of chuckle when I read your letter, as I just helped a neighbor with the same problem on a '94 Chevy. Replacing the fuel pump on this fuel-injected vehicle involves dropping the fuel tank. This is not a fun job. Anyway, you're on the right track when you think about proper grounds. You should also check whether the pump is getting the proper amount of voltage. Lower voltage means the pump motor may be overheating, though this isn't usually the case with a DC motor that is submerged within the tank. One other thought is that there may be a problem in the fuel-return line. If there is a restriction reducing the flow of unused fuel back to the tank, then the pump could be doing more work than it's designed for, thereby shortening its life.
Question: In "Willie's Workbench," (July '04), you discussed making high- and low-beam lamps all burn at the same time on GM four-headlight systems. I have the same question with regard to the Jeep XJ Cherokee two-headlight system. I can wire it so the low beams stay on with the high beams, but I don't know if that is OK to do. Do you know if the lights or wiring will get too hot if I do this, or of any other problems that might arise with both filaments on? I sometimes do as you described-momentarily hold the high beam flasher to get more light.
San Dimas, California
Answer: I've been told that if you wire your XJ this way, you will overheat the bulb and shorten its life dramatically. However, my CJ-2A has an MB grille with the small 5-inch headlights containing 12-volt halogen sealed-beam bulbs. I wired the low and high beams on separate circuits so I can use both. While it doesn't get a lot of night driving and probably doesn't have a total of four hours of high-beam usage, they are still working. I say, try it, knowing that it could cost you some headlight bulbs, and let us know how it works.
Question: I'd like to ask you about wheel spacers and the different materials they are made from. I have been seeing more and more high-dollar rigs using wheel spacers-and aluminum ones at that. So, what is the better material-aluminum or steel? On the cover of the May '04 issue of Four Wheeler there was a photograph of a '00 Dodge Durango using 2 1/2-inch billet-aluminum spacers. I use the steel spacers myself, and they are pretty heavy. I recently saw a Chevy Avalanche on the cover of another magazine using aluminum spacers. Steel is stronger, but heavier, while aluminum is a softer material and lighter. If the guys who own these $100,000 rigs are willing to run billet-aluminum spacers, are they good enough for my 3/4-ton Chevy 4x4?
Answer: The aluminum wheel spacers seem to work just fine. There are several companies offering them, so I suggest you do some research into their quality. Just because they're made out of aluminum doesn't mean that they don't have the necessary strength. There are, however, several things you need to keep in mind if you choose to use spacers. A couple of things will change, including the steering and scrub radii, which can lead to faster tire wear. Because you're moving the center load point of the tire outward, you're putting more leverage on the hub and spindle. If your rear axle is of the light-duty type with a flanged axleshaft, you're putting more load onto the axle bearings. Whether this will cause a problem or not depends on just how you use your truck, and the amount of load you carry.
Question: I have a '95 Dodge Ram with four-wheel drive. Its transmission recently failed. I have 38x15.50-15 Ground Hawg tires on it. Do I need to reduce tire size to prevent the problem, or swap out gears? It still has the factory Dana axles and gears on the truck-someone told me they were 3.55s. Could that be my problem?
Answer: It's really impossible to say that the tires were the cause of your transmission failure, but with that high a gear ratio and 38-inch tires, there's a good chance that the combination helped your rig's trans to an early demise. The overall higher gearing that results from using taller tires puts an extra load on the drivetrain components and would have a tendency to cause higher transmission-fluid operational temperatures. High fluid temperature is the number-one cause of transmission failure. So do yourself a favor and really consider swapping the present gears out for something else-most likely in the 4.56 range.
Question: I recently bought new keys for my truck's torsion bars, had them installed and the torsion bars tightened on my '01 F-150 Supercrew. The problem I'm having now is that I keep blowing the passenger-side CV axle and/or blowing the inner boot, but only on the right side. I'm also hearing a popping sound when I make a sharp turn at slow speeds, as well as having trouble with the truck's front-wheel alignment. I really feel that the Ford garage is giving me a runaround telling me it's only a loose bolt or a bad clamp in the boot. I am currently deployed in Iraq and am trying to keep in touch with the dealership, but they just don't seem to know what's going on. I'm relying on that vehicle to get home when I return to the States, and just need to find some direction on this.
Answer: My guess is that the angle of the axleshaft is too great for the CV joint (the raised ride height and/or the steering angle is too tight). Either one of these issues can put the CV joint into a bind and cause the boot and joint to be damaged. The popping sound is most likely coming from the balls binding in the CV joint. If the joint ran very long with a damaged boot, the grease came out and most likely there was not enough lubrication on the joint. The alignment problem can also be the result of the higher ride height.
Question: Are throttle-body spacers all they are said to be? I am looking for cheap power additions for my '91 Ranger 4.0L. What do you think?
Answer: Some engines respond to throttle-body spacers better than others do. This variability in response has to do with manifold design. I have no idea if the addition of a spacer will help yours. In any case, any improvement you may get is generally not something you'll feel on a "seat-of-the-pants" basis.
Question: I purchased a '79 GMC 1/2-ton about a year ago. I think it has a full-time four-wheel-drive transfer case, as on the shifter knob it has Lo-Loc, Lo, N, Hi and Hi-Loc with locking hubs. To utilize four-wheel drive, it has to be in the Hi-Loc (or Lo-Loc) position, as in Hi with the hubs locked it is just in two-wheel drive. I was just wondering if I use Hi-Loc for four-wheeling, or is there something wrong here?
The truck came with a 3-inch body lift and blocks in the rear. It rides really rough and I was wondering if a suspension lift would be a good fix? Could I also just do a rear-shackle flip instead of spending money on a lift? The front springs are arched down, so could I have them re-arched and flip them (to arch up) and thus gain clearance?
Answer: Sounds to me like your truck has a full-time transfer case, and that someone, at one time in the truck's life, put in an aftermarket part-time kit. If that's so, you no longer have the full-time four-wheel-drive system. Most likely it was done with the anticipation of better fuel mileage. My guess is the reason your truck rides rough is that the front springs have pretty much lost their ability to support the vehicle after some 25 years, and you're banging on the bumpstops. I wouldn't recommend re-arching the present springs. Instead, buy one of the numerous lift kits that are available. I am also sure that a set of quality shocks will also help improve the ride quality. Yes, it is possible to flip the shackles on the rear springs to gain some ride height.