Confused? E-mail your questions about trucks, 4x4's, 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 Web site (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
E-mail to:
nuts@4wheeloffroad.com
Question: In what model years did Jeep use the 4.2L engine in the Wrangler and what were the horsepower and torque ratings? Also, did they "downsize" to the 4.0 or is that an entirely different engine?
T. Steele, via 4wor.com
Answer: Jeep has been using a straight-six engine since the '50s with various models including the 226 L-head Super Hurricane used from 1953 and then the 230ci Tornado OHC six in 1963. In 1965 the AMC 232 High Torque I-6 took over and this slowly evolved into the 4.2L 258 found in many CJs and early YJ Wranglers starting around 1972 and running until 1990. The 258 is a great engine-torquey and tough-but it was never offered with fuel injection. It was basically a stroked version of the 232 and put out roughly 150 hp and 240 lb-ft of torque. In 1987 the 4.0L straight-six was introduced and, though it had a smaller displacement, it offered more horsepower at 190 with a slight drop to 225 lb-ft of torque. This engine is commonly thought to be better than the 4.2 since most years it came with fuel injection, and is more fuel efficient, reliable, and powerful. The 4.0 stuck around until just this year when the new JK Wrangler was introduced, and the only engine available now is the 3.8L V-6.
Question: Our '90 Toyota Extended Cab 4x4 pickup is our daily driver, so stability on the highway and low road noise are important since most of the truck's life is spent on asphalt. But the reason we have the truck is that we got tired of getting stuck in the mud on our bush lot.
The drivetrain and suspension are mostly original equipment. (We live in the Rust Belt, so it's on its second body and third paint job). The 33x12.5 off-brand tires have been good in the mud and have taken us places where the other trucks get buried, but they are getting worn out. The old tires' highway manners are OK, but they are noisy, noisier than our 31-inch snow tires. What tires would you recommend that will still get us through the mud but will have good highway manners and reasonable road noise?
Peter T., via 4wor.com
Answer: One of the quietest tires I have tested is the Toyo M/T Open Country. These tires have great highway and dirt characteristics and I have friends who really like their performance in the snow as well. There are a lot of great tires out there, and most mud-terrain tires get louder as they get older and the miles of use increases, but I would look into the Toyos for your situation.
Question: I have a '91 GMC Jimmy that has a 14-bolt rear that I installed 4.88 gears and a Detroit Locker in about two years ago. It is my daily driver and everything worked fine until about two weeks ago, when I noticed a loud clank (it got worse and worse) every time I would put the truck from Drive into Reverse or vice versa. I crawled under it and with the tranny in Neutral. I noticed that the driveshaft had about 180 degrees of free turning play. Except for the annoying clank it seems to drive normal.
Now, I know that is a lot of play on the driveshaft and I haven't opened up the diff yet. I would like to know what to expect when I drop the diff cover, and what caused this to happen.
Gabe, via 4wor.com
Answer: I ran your question by Scott Frary, the aftermarket sales manager for Eaton Detroit Locker, and got the following answer:
"180 degrees of slop is excessive. The most I ever see is less than 1/3 rotation. This excessive rotation is most likely the result of many different components. Sloppy driveshaft U-joints, ring-and-pinion wear, axle and/or driveshaft spline wear, and Detroit Locker backlash all can add up to excessive lash. Regardless of the cause, I'd recommend that the owner check all of these components, including the Detroit, for damage."