Submission Information
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
6420 Wilshire Blvd.
Los Angeles, CA 90048-5515
fax 323.782.2704.
Email to:
nuts@4wheeloffroad.com
Cognito Click
Question: I have an '08 Chevy 3500HD. I put on a Cognito leveling kit, BFGoodrich 305-70R16 MTs, and Mickey Thompson classic lock wheels about 5,000 miles ago. Now I hear a faint clicking noise that I believe is coming from the unit bearings. Do you guys know if this is common with unit bearing setups, or is there a kit available to convert to standard bearings?
Kyle
via 4wheeloffroad.com
Answer: Kyle, the IFS on your truck has a bunch of moving parts, but I kind of doubt that the clicking is from the unit bearing on such a new truck. First I would have a friend drive the truck around a parking lot slowly while you walk beside it and listen for the clicking. Determine if it only happens on one side. Does it speed up and slow down with the wheel speed, or is it constant? Does it happen with braking or steering?
Now put the truck up on jackstands (under the A-arms if safely possible) and spin each tire to see if it's still clicking. Also turn the front driveshaft and see if it's clicking. This will help establish if it's in the transfer case. Now move the jackstands to under the frame so the A-arms droop completely, and listen again. My first suspicion is one of the CV joints is clicking. Look for a torn boot or busted CV cup.
Now you can try and wiggle the tire in and out at the top of the wheel to see if the unit bearing is failing. Also pull your wheel and tire and look at both the brakes and inside your center cap on your wheel. It might just be something clicking inside there.
Unit bearings have a pretty long lifespan, though they do fail eventually. I do wish there was a kit to convert from a unit bearing to a spindle and bearing for IFS GM trucks like there is for Dodge and Ford straight-axle trucks, but no one has developed one yet.
Never-Ending Argument
Question: Lately I have been wondering which is more important, engine size or gearing? I am looking to build an all-around rig. I have heard of many people who put V-8s in Mini-Toys. But I also know even more who stick with the 22RE and just double up on transfer cases and run different gearing. So which is better? Bigger engine or different gear setup?
Steve
via 4wheeloffroad.com
Answer: What's better, blondes or brunettes? Apple pie or cherry pie? Chocolate cake or... Well, nothing's better than chocolate cake but let's get back to the topic at hand. Engine and gearing are both important depending what terrain you're looking to run and what size tires you plan to run.
My Toyota, Clampy, has 7.17 axle gears, 40-inch tires, and a 100hp four-cylinder. My Fun Buggy has 8.07 axle gears (Axletech Portals and 5.38 ring-and-pinion), 40-inch tires, and a 400hp V-8. When it comes to rockcrawling they both work pretty equally. However, as soon as I need wheelspin for sand, mud, snow, or really loose climbs, the 400hp Fun Buggy makes an impressive show, throwing rocks and debris everywhere.
Now I'd never admit that Clampy isn't the most perfect truck ever, and it will usually make it through stuff like mud and snow; it just takes a little longer. In my view you don't need as much gearing if you have a healthy big motor, but it definitely helps. However, if you don't have engine you definitely need gearing. Consequently both big and small engines can benefit from gearing. Gearing eases the strain on engines and components when they have to turn big tires, and gearing allows for more control when technical rockcrawling, so gearing is more important than engine (but more power can equal more fun).
Better Off Set Boxes
Question: Can you explain why there aren't more kits similar to the one Calmini sells for the Samurai to allow for a high range reduction in the transfer case? The kit Calmini sells reduces both high and low range, with the reduction of 18.3 percent for the high range. I know there are trucks out there that have high ranges lower than the standard 1:1 (my '01 Land Rover Discovery II high range is 1.211:1). If I could have a high range similar to my Discovery II for the BW1354 transfer case in my '89 Bronco II with 33s, then I wouldn't need to change the 3.73s in the diffs to compensate for the increase tire size. Why haven't other companies designed them for other applications?
Steven W. L
via 4wheeloffroad.com
Answer: Both the Suzuki Samurai and the Land Rover Discovery transfer case you mention have an offset rear output so that both the front and rear driveshafts are in line along the passenger side of the truck. This design was very common 50 years ago, as it makes for great driveshaft angles and keeps the differentials in line, making dodging trail obstacles that much easier. This layout also requires all the drive rotation to go through some gearing, and thus it is easy to add some gear reduction.
In most current transfer cases the rear output is centered, and when in high range the input shaft and output shaft are coupled straight together. In order to add some gearing between these two you would need a larger case to put all the gears in. The old Spicer Model 18 transfer case found in many Jeeps is also an offset case, and because of this the Saturn overdrive from Advance Adapters can be installed to make up for extremely low gearing in the axles.
Another thing to consider is that gear reduction closer to the tires reduces stress on components such as driveshafts and U-joints, and that's one reason why I'd recommend low axle ring-and-pinion.
More Gear Queries
Question: I have an '02 Toyota Tacoma Double Cab SR5 TRD. It has a 6-inch suspension lift and 35-inch Baja Claws, but still retains the stock 4:10 gears and factory e-locker. I will be upgrading to 37-inch Baja Claws while adding another 3 inches of suspension lift. I have spent months reading through various articles and I am undecided between 4:88 or 5:29 axle gears. I want the ride to be as close to stock as possible, as I drive this daily and wheel on the weekends. Eventually I will be adding more weight with front and rear bumpers, a winch, a roof rack, and gear, as well as a supercharger and seventh injector, with modified computer or piggyback.
Anthony
via 4wheeloffroad.com
Answer: When going to lower gearing I usually err on the side of too low. I take it that you are a fan of mud. Unlike the rocks I usually play in, mud does not usually require as low gearing. On the other hand, consider that not only are you going to a taller tire but also a heavier tire with larger rolling resistance. We have 5.38 gears in our 5,800-pound FJ Cruiser running 39-inch tires, and with the six-speed manual and supercharged 4.0L it runs down the highway no problem. I say 5.29s. With the added weight you'll be glad you have it.
...
>>next page