Q I'm confused and need some assistance. Winter approaches, and I am now the owner of an '04 Chevy Avalanche 4x4. We get good amounts of snow and ice, so here is my question. It has the typical 2WD, 4-Hi, and 4-Lo. But it also has auto 4WD. I am wondering which one to use. 4-Lo is best in the really bad stuff, but the 4-Hi or auto 4WD is where I need help. I would appreciate any help on this so that I don't tear anything up or get stuck. Thanks.
Great Bend, KS
A Your transfer case is an GM AutoTrac. It has clutches inside that allow the front and rear axles to spin at different speeds when in auto 4WD but continue to transfer power to the axle with the most traction. Auto 4WD is what you want for snowy roads. This way you can drive on hard asphalt with all four tires driving but also have traction on hand for icy or snowy patches. 4-Hi connects the front and rear driveshaft, whereas 4-Lo also adds additional gearing. 2-Hi only sends power to the rear axle. It is recommended that 4-Hi and 4-Lo be used only on terrain that has some give, such as dirt and mud or rocks and snow. On asphalt or snow-covered asphalt, use auto 4WD or 2-Hi.
Nuts, I'm Confused
Q I am rebuilding an '88 Toyota 4Runner from the ground up, and I have a couple questions that are bugging me. I would really appreciate your input. This truck will spend 85 percent of the time on the street with an occasional trip to Turkey Bay OHV and some time on logging roads for hunting and fishing.
I want to replace all the bushings and body mounts, but I can't decide between rubber and polyurethane. I know urethane will improve street performance, but how much of an impact will it have off-road on a basically stock truck?
My second question is about wheel diameter with smaller tires (31-33 inches). Larger wheels and shorter sidewalls on the tires also help street performance, but how much does this take away from the tires' performance off-road if they are not aired down? This is going to be a true dual-use truck, and I want to get as close as I can to "the best of both worlds."
A I can understand your concerns over rigidity versus flex between rubber and poly, but I think the poly bushing offer excellent longevity versus rubber. Having suspension bushings with a slight amount of flex is important, but too much movement can be a problem also.
I took your question to the crew at Daystar and got the following response:
"It looks like you have a project with great potential; those Toyotas are practically bulletproof, and with a little TLC your 4Runner should provide years of reliable service. Considering the age of your vehicle (again, it's an oldie but a goodie!), one of the most dramatic handling improvements you can make to your vehicle is replacing the worn-out rubber components with polyurethane.
"There are several advantages to using polyurethane. First is longevity; as you can see with your stock rubber parts, rubber breaks down over time as it is subjected to the elements and vehicle fluids. Polyurethane is highly resistant to chemicals, the elements, and road grime; basically it will last for the life of the vehicle. Polyurethane also offers less deflection under load, which means that it improves handling by keeping the suspension components firmly in their mounts, while rubber allows the components to move around in ways other than desired.
"These handling improvements will be equally appreciated both on- and off-road. Cornering will improve on the street, while the suspension will feel more precise and surefooted when blasting down those logging roads. Even the polyurethane body mounts will help by keeping the body properly centered on the frame and eliminating the movement that the stock mounts are no doubt allowing now.
"The last thing to consider is cost and availability. Several affordable polyurethane master bushing kits are available for your vehicle, while you may have trouble finding replacement rubber bushings and body mounts for your vehicle, and they will most likely be more expensive than their polyurethane equivalents."
Here is the best part: the Daystar folks are going to send you a kit for your truck as the prize for writing this month's Nuts, I'm Confused letter! Thanks for your letter.
Confused? Email your questions about trucks, 4x4s, and off-roading tech using "Nuts, I'm confused" as the subject and include a picture (if it's applicable). Digital photos must measure no less than 1600 x 1200 pixels (or two megapixels) and be saved as a TIFF, an EPS, or a maximum-quality JPEG file. Also, I'll be checking the forums on our website (www.4wheeloffroad.com), and if I see a question that I think more of you might want to have answered, I'll print that as well. Otherwise drop it old-school style with the envelope addressed to the address below. Letters published in this magazine reflect the opinions of the writers, and we reserve the right to edit letters for clarity, brevity, or other purposes.
Write to: Nuts & Bolts, 4-Wheel & Off-Road, 831 S. Douglas St., El Segundo, CA 90245
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