December 2005 4x4 Truck Repair Questions - Nuts & BoltsPosted in How To on December 1, 2005
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. Always check state regulations before modifying a vehicle with pollution controls or one that will be driven on the street. We will answer as many letters as possible each month, but due to the large volume of mail we receive, we regret that we cannot reply to unpublished letters or return photos. 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.
Nuts & Bolts
4-Wheel & Off-Road
6420 Wilshire Blvd.
Los Angeles, CA 90048-5515
Jeep Code Names
Question: I know that this may seem like a stupid question, but I'll ask anyways. When I go to buy parts for my Jeep I don't know how to tell whether I have a TJ, CJ, or XJ model. It's a '99 Sahara with a 4.0L engine. I feel as lost as a 3-year-old at Wal-Mart who got separated from his parents.
Ft. Carson, CO
Answer: Your '99 Wrangler Sahara is a TJ. The previous ('86-'95) Wranglers are considered YJs. Jeep Cherokees from '84 to '01 are XJs. All Libertys are KJs and Grand Cherokees are ZJs ('93-'98), WJs ('99-'04), or WKs ('05-and-newer). A CJ can be pretty much any small Jeep built from '44 to '86.
Land Cruiser Axle Strength
Question: I am in the process of building up a '76 Toyota Land Cruiser FJ-40. I'm putting a new 5.3L Vortec powerplant along with an NV4500 transmission and an Orion HD 4:1 transfer case in the mix. My question is regarding the stock Toyota axles. I know several people with FJs, but I am getting mixed information from them. Some claim that the Toyota axles are quite stout-nearing the strength of a Dana 60 axle. Others tell me to swap them for Dana 44 axles. I have searched the Internet for answers, but all I can find is opinions. Can you tell me if my stock axles are up to the task of handling my new drivetrain? I will be running 35-inch tires and may go to 37s in the future, but no bigger.
Cedar City, UT
Answer: Daily driving and normal wheeling won't be a problem with your combination. On the other hand, if you're into extreme driving with lockers front and rear you may be pushing what the stock Toyota pieces can handle. Despite what your friends say, the Toyota axles are just as strong as Dana 44s. So if you were going to swap out what you have you'd be better off stepping up to Dana 60s.
The Dana 44 may have an advantage when it comes to parts selection and availability, but on the other hand, your Toyota axles benefit from an inch larger ring gear (911/42 vs. 811/42-inch). What's the weak link? Probably the Birfield joints in the front axleshafts and the rear axle pinion gear. Aftermarket axleshafts (with beefier Birfields) are available from Marlin Crawler (559.25.CRAWL, www.marlincrawler.com), Poly Performance (805.783.2060, www.polyperformance.com), and Longfield Super Axles (253.843.0551, www.toyotasuperaxles.com). All the aftermarket ring-and-pinion gearsets we know of use the stronger 27-spline pinion found in later-model ('78-and-newer) axles, so there's room to upgrade if you start having breakage issues.
Chevy Suspension on a Ramcharger
Question: I have an '85 Dodge Ramcharger. A friend has a 2-inch lift kit for a '76-'87 Chevy Truck. Will this kit fit my Ramcharger? I have read that early Chevy and Dodge suspensions are nearly identical. Is this true?
Answer: This is a classic case of trying to use what you have instead of the correct part for the job. Yes, we've seen this swap done, but that doesn't make it a good idea. The leaf springs are very similar between the two trucks but they're not the same. Typically for a given ride height the Dodge springs are at least an inch longer than the Chevy version. On top of that, the spring eyes are wider on the Chevy springs, and the rear spring eye is above the spring instead of below it as on the Dodge version. Using the Chevy springs could cause pinion angle problems, bushing wear issues, and a terrible ride quality just to save a few bucks. Don't waste your time. Get the correct Dodge springs.
The Best Off-Road Transmission Shifter
Question: I've been looking at ratchet shifters and gate-type automatic transmission shifters for my 4x4 project. I like the idea of a ratchet shifter, but it seems it would be difficult to shift from First gear to Reverse if I had to rock the vehicle out of a mud hole. At the same time gate shifters don't seem to give the kind of solid shifts that a ratchet would provide. I don't plan to drive my truck in any competitions, but I do plan to drive it hard. Any guidance would be appreciated.
Virginia Beach, VA
Answer: If the stock column shifter doesn't suit your needs then we'd recommend a gate-type cable shifter like the ones available from the Art Carr (888.526.5868, www.artcarr.com), ATI/Winters (800.284.3433, www.atiracing.com), and California Performance Transmission (800.278.2277, www.cpttransmission.com). They're all based on Morse Controls components originally designed for medium-duty trucks with Allison transmissions. These gate shifters give a positive shift feel and are almost jam-proof, and the shifter gate can be custom-ground to permit quick First-to-Reverse shifting.
2WD to 4WD Conversions
Question: I would like to convert my two-wheel-drive Dodge Dakota pickup to four-wheel drive. I have a fabrication shop at my disposal. Would it be better to use leaf springs or the new Dodge fullsize stock four-link arms?
Ft. Lauderdale, FL
Answer: When building a solid-axle front suspension it's almost always easiest to use leaf springs. They may not be ultimate for flex, ride, or the cool-guy factor-but they are hard to beat for their simplicity. The ideal front axle seems to be a Dana 44 or Dana 60 out of a '78 or '79 Ford F-250 that has perches for the leaf springs. It'll require you to get a matching rear axle, but they are a dime a dozen. The '73-'87 GM front leaf springs are the most common (and cheapest!) so we'd track down a set of 4-inch lift springs to do the mockup. You'll need to fabricate some sort of front spring hanger and rear shackle pivots to locate the axle. The Ford axle has approximately 3111/42-inch spring spacing, so the front hangers are going to sit outboard of the framerails and the rear shackles will need to fit inside the framerails near the transmission crossmember. Pay attention to pinion angle, as well as the shackle angle when the truck is at its final ride height. And don't forget you'll need a transfer case.
Tech Tip Of The Month
Proper Break-In Practices
Question: In my '78 Ford Bronco I have a rebuilt 14-bolt rear axle and a rebuilt Dana 60 front with 5.13 gears, lockers, a rebuilt C6 transmission, and a brand-new torque converter. While the parts were getting rebuilt, I put a 6-inch suspension lift, a 2-inch body lift, and 38-inch tires on it. Can you please tell me how to break these parts in without damaging one of them?
Mount Pleasant, NC
Answer: When we install new ring-and-pinion gears we follow the manufacturer's recommendations for proper break in. Typically that means filling the differentials with a gear lube and running the truck around town for 15-20 minutes till the differential cover feels warm to the touch. If you have manual locking hubs, go ahead and lock them so the front gears spin too. Just make sure to leave the transfer case in two-wheel drive. During the break-in process you want to go easy on your truck. Don't do any burnouts or dragstrip launches. Let the axles cool down for 30-40 minutes, and then drive it for another 15-20 minutes to heat the gears up again. Make sure to listen for any unusual noises and check for leaks. In a perfect world we'd repeat this process five times before taking the truck on the highway. And whatever you do, don't tow anything with your Bronco till you've put 500 miles on the new gears.
At around the 500-mile mark pull the differential covers, drain the gear lube, and spray the gears down with carb cleaner to make sure any junk that's in the axlehousing gets rinsed out. If everything looks good, replace the differential coves and refill the axles with new gear lube (don't reuse the old stuff)! While you're under the Bronco we'd also replace the ATF and transmission filter (or clean the screen) in the C6, and replace the gear lube in your NP205. It would also be a good idea to go around and retorque all of the lift kit hardware, and check the lug nuts to make sure everything is still tight.