Tire Hardness Temp Foul
I call foul on your “How We Test Tire Hardness” story in the February 2014 issue. In that story, it looks like the tire is probably off the vehicle, so how could you get the tire to 145 degrees to check the rubber hardness?
Sam, you are in fact correct that the tire was off the vehicle. The images and story were simply meant to be a demonstration of how we test the tire hardness and why recording temperature is important. We used an artificial heat source (a heat gun) to get the tread surface temperature up that high, which means that 145 degrees was not a uniform temperature around the tire. It was only that warm on the tread area we selected to distribute heat. Asphalt surface temperatures can easily reach 145 degrees during summer in much of the country, so this is not an unreasonable amount of heat to introduce to the tread surface. We are confident the Trepador tire we used would have a rubber hardness close to the 62 out of 100 that we recorded in the story. Thanks for keeping a close eye out!
Thought I’d send you some update pics on how my CUCV Blazer was turning out. I originally wrote you about a CJ-7 I had, but I ended up trading it for this cool military Blazer. I have a front Dana 60 and a rear 14-Bolt, and a very cool and low 42,000 miles!
Death Wobble Woes
Hello, I have gotten help and support from you in the past and am looking for more help. I have a ’93 Jeep Wrangler that seems to have what some call death wobble (that shaking in the front end). My friend who has a TJ told me a YJ cannot get death wobble because to his knowledge only vehicles with coil sprung suspension systems could get it. Anyways, I have what is like death wobble when driving down the highway at speeds greater than 65 mph.
What I have done so far: I have looked over the tie rods, ball joints, bushings on multiple components, the wheel bearings, and even gotten the Jeep realigned. Everything turned out looking okay and had no slop. I then had the tires rebalanced and rotated and checked the rims to make sure they were not bent. But still had the same issue. I then had my dad’s friend who works at a repair shop look everything over (he does state inspections for me every year, as well) and he said everything was okay. Lastly, I recently noticed I had no bumpstops underneath and replaced them along with redoing my brake lines. To my surprise, when I drove the YJ again -- all the way up to 80, as fast as I want to drive -- there was no shaking. Would missing bumpstops cause these symptoms or have I been lucky? Also, I just got my 2.5-inch Pro Comp lift and am about ready to install it. Is it a good idea to replace the tie rods, ball joints, and wheel bearings while installing it or should I just wait until they wear down? (As a side note: I am not going to bigger tires, I am staying with the 30-inch tires.)
Thank you for the help.
Nicholas, a leaf-sprung vehicle can definitely get death wobble (as you found out yourself). Common death wobble contributors are out-of-round tires, worn-out steering links, worn-out track bar bushings (why some people believe only linked vehicles can get it), and incorrect caster.
With a stock leaf-sprung vehicle with good (as you claim) tires, bushings, and steering components, it is very curious you were getting wobble. And even more curious why bumpstops would help cure it (or affect it at all unless your Jeep sits on the bumpstops at ride height).
As for the Pro Comp 2.5-inch lift: We think you should feel confident that putting a 2.5-inch spring lift on your Wrangler will not affect your drivetrain angles or steering too adversely. Don’t worry about replacing wheel bearings, ball joints, and such until they wear out. Unless you’re a rich guy, in which case, it’s always a good idea.
One question: Why do you want to add lift if you’re not putting on larger tires than you already have? If you can fit the tires you have now and don’t want any bigger of a tire, then your Jeep will drive best if you keep it at the stock ride height. You can purchase better-riding aftermarket leaf springs with no amount of lift; it’s just common for most off-roaders to want bigger tires, so off-roaders want lift kits to fit the tires.
Sure, it works great for the first week, but what about after?
A couple years ago we finally got our red ’94 Dodge, Jinxy, the suspension we’d always wanted it to have: A nice, clean four-link-and-track-bar setup that would not flex, not hang low, and not be so long the arms went halfway down the frame. Off Road Evolution -- a company known for high-end Jeep builds and EVO suspension -- adapted a JK-like four-link onto our red Dodge. Considering our built half-ton Ram 1500 single cab short bed truck is lighter than a built four-door JK, we had full confidence the suspension would hold up under our truck. And two years later, we are still loving the EVO links that hold the front Dynatrac Pro Rock 44 axle.
What’s going on in the off-road world
Johnson Valley Deal Reached
A provision to expand the Marine Corps Air Ground Combat Center, Twentynine Palms, California, and preserve off-highway vehicle (OHV) access to Johnson Valley is contained in Subtitle C of the National Defense Authorization Act (NDAA) of 2014. Leaders of the House and Senate Armed Service Committees announced an agreement on the NDAA on December 9, 2013. The U.S. House of Representatives approved the bill on December 12. The U.S. Senate is set to ratify the bill during the week of December 15, and to be signed into law by President Obama.
SEMA tells us that the off-highway motorized recreation community considers this groundbreaking provision a “win” for both the OHV community and the United States Marine Corps. As a result, Johnson Valley will be designated by Congress as the “Johnson Valley Off-Highway Vehicle Recreation Area,” under the continued management of the U.S. Bureau of Land Management (BLM).
The provision creates the Johnson Valley Off-Highway Vehicle Recreation Area, providing federal protection to an area established in 1980 for OHV recreation by the State of California. It is the first time an OHV area has been provided national recognition.
Three land areas have been designated for specific types of use: 1. Johnson Valley OHV Area; 2. shared use area; 3. exclusive military use area. Acreage numbers were taken from Congressman Paul Cook’s website at presstime. (See map.)
The Johnson Valley Off-Highway Vehicle Recreation Area includes:
43,431 acres OHV exclusive
56,439 acres shared use (military use up to 60 days a year)
99,870 total acreage
The Marine Corps’ Military use and shared use areas include:
Exclusive Military Use Area:
88,130 total acreage
Shared Use Area:
56,439 total acres
According to the provision, the Marine Corps must provide access between the two non-contiguous areas included in the Johnson Valley OHV Recreation Area (northeast corner of OHV Area). The exclusive military use area boundary should be clearly identified and maintained by the Marine Corps (for example, fences). It will be able to engage in large-scale, live-fire field training exercises on this land any time during the year.
The KC Hilites/Glass Chiropractic Racing Team recently competed in the Henderson 250, final stop of the 2013 BITD series. The combination of 1st and 2nd place finishes at four of five events (this season) gave the team a comfortable lead, and per the rules, they only had to take the “green” in order to seal the deal. This wraps up five years in the team’s “new” truck, and five consecutive class 8000 championships.
If you’ve got something to say or ask, you can reach the staff of Off-Road magazine at firstname.lastname@example.org at the old email addresses previously published.