Your Tech Questions Answered
Nuts, I’m Confused
Escape the Inner Circle
Q I have a question about U-joint repair. In the Nov. ’10 story “Universal How-To” you show how to repair U-joints with external snap rings. I have an ’01 Dodge 2500 with a Cummins diesel. I am trying to install a “Spyn Tec “ unit bearing replacement kit on the front axle. The stub shafts have internal snap rings, so how do you remove the bearings?
A The inner snap ring on an axle U-joint cap isn’t too hard to remove, but it depends on the type of snap ring you have.
Most factory joints have a C-clip. This is a snap ring that isn’t a complete circle, but just a “C.” Often these have the outer edge of the axle joint yoke machined so that the clip doesn’t go all the way around the U-joint cap. I have found that removing these is done with a pick, small strong flathead screwdriver, or small punch or chisel.
Most of the aftermarket steering axles have “full circle C-clips” for the U-joint caps. These will require snap ring pliers to spread the clip and then slide it down toward the cross of the U-joint. As you spread the snap ring you may also need to get that small flathead screwdriver under it to help get it away from the axle yoke.
Once the snap rings are off you can press or tap the U-joints out. One method is to hit the one yoke while the other is secured in a vise. I have also used a socket the size of the U-joint cap to hit against with a good sized hammer. Care should be taken to keep all the needle bearings within the cap during disassembly and reassembly.
Finally, there may come a point where the cap is sticking out and you need to grab it with a set of Channel Lock pliers to twist it out the last little bit. Be careful not to scar the cap or else you won’t be able to reuse it.
This is a good question and only really requires simple handtools to do the job, but it may seem daunting if you’ve never done it before. I’m awarding you a gift certificate from Off-Road Power Products for sending in the Nut’s, I’m Confused letter of the month. Off-Road Power Products has an online store with a variety of great truck and 4x4 products from Jeep stuff to fullsize off-roaders. Check it out at www.offroadpowerproducts.com.
Q I am interested in installing an overdrive in my truck. I am currently building a ’70 Chevy K10. It has a well-built 327, a four-speed manual, an NP205, a Dana 60 front with a 14-bolt out back with a disc brake conversion, 35-inch BFG MTs, and crossover steering. I’m building it into a basic do-everything-well trail truck. It will be about a 50/50 split for on- and off-road use. Some 4.56 gears and lockers are in the works as well. I want to keep the four-speed for its simplicity and strength.
I am interested in the Gear Vendors overdrive or the Advance Adapters Ranger overdrive unit. I want to know which one would be the better choice for my setup and intended use. I drive pretty hard and don’t want something that will puke its guts out on the trail. I also intend on towing trailers. Now I know that you guys might recommend just doing an NV4500 conversion, but I want to be able to split gears and basically have an eight-speed.
A I have personal experience with the Ranger overdrive, and I like it for a few reasons. You can use it while the vehicle is in four-wheel drive, unlike the Gear Vendors. It is compact and proven with nearly 50 years of use. It is simple to install with a GM four-speed—I assume you are using the SM465. It does have one major downfall and that is gear whine. I can hear it spinning while driving my open-top M-37, so be warned that if you are annoyed by the sound of your truck doing cool stuff like cruising down the highway then you may not like this gearbox. Advance Adapters (www.advanceadapters.com) does only rate it to 420 lb-ft also, so keep that in mind if you are building a big engine. I assume your 327 would be fine.
The Gear Vendors (www.gearvendors.com) unit bolts onto the back of the 205 so it can only be used in two-wheel drive. It cost twice as much as the Ranger. Gear Vendors claims that its overdrive has lived behind 850hp desert racing trucks.
A third option you may want to consider is raising your axle gears to a numerically lower number like 4.10. You’ll have the granny First gear to help get moving on the street, and when matched with the 35s you shouldn’t be winding up the rpm’s on the highway. Then add a doubler like a 203/205 to your transfer case, and this will give you lower gears for when you need it off-road. Of course, this doesn’t help when you want to split gears, but it is another option to consider.
16.5 Dead or Alive?
Q I am building a ’91 GMC 1-ton Crew Cab 4x4 V3500 (square body) single-rear-wheel truck. It has a factory 454, a 4L80E, a Dana 60 front, and a 14-bolt rear. A 12-inch lift and crossover steering are being installed, and it’s time to find some wheels and tires. I wanted to run 16.5x14 rims with 40-inch tires, but it looks like 16.5 rims and tires are going the way of the dinosaur. I like the look of the 17- to 22-inch wheels, but I don’t want to spend $3,000 on tires every time I need a new set. Are 16.5 tires going to be available for the next 20 years? Should I step down to 15x14s? Or should I just suck it up and get some dubs so I have more tire options in the future?
A Sorry, Mike, I would suggest you get a set of 17-inch wheels. The 15s and 16.5s are slowly disappearing. I’m not saying they won’t be around for 20 more years, but 17s are much easier to find and offer a greater selection of tires. If you find a set of 16.5s cheap I’d run ’em, but 17s and larger are definitely the future. Don’t waste your time trying to fit the 15s over your big brakes; it’s not worth it. I don’t care for the look of 20s or 22s, but that’s just me. I think the selection of off-road tires is larger in 17s or 20s.
I also don’t think you need a 14-inch-wide wheel for 40-inch tires. Most 40s are a 13.50 or 14.50 wide, and these are fine on a 10- to 12-inch wheel per most manufacturers. I run 40s on a 17x8.5 beadlock all the time with no issues.
One suggestion I would recommend is find a wheel with about 5 inches of backspacing. This will help reduce the stress on your bearings by reducing your scrub radius.