Your Tech Questions Answered
Scout Out a Transfer Case
Q: I picked up a ’73 Jeep Commando a few months back, and the guy I bought it from knew very little about it. He said that the transfer case was a Dana 20 out of a Scout. I want to swap in a Dana 300 so I can do 4:1 low range gears. Is there a difference between the Dana 20s/Dana 300s from Scouts and the ones that came in Jeeps?
A: The Scout/Jeep Dana 20 has what is known as the Texas bolt pattern because it sort of look like the shape of Texas; this is shared with the earlier Jeep Dana 18 and only the Scout Dana 300, not the Jeep Dana 300. As such, the Scout Dana 300 should bolt up where your Dana 20 currently is. However, you will need the proper input splines. If you have an automatic the input will have fine splines, a manual will have coarse splines. The problem arises in that the Scout Dana 300s are getting harder and harder to find because they were only made for one year, 1980.
If you have a manual transmission then you could use a 3.15:1 low range gearset from Teraflex (www.teraflex.biz) for your Dana 20 and not even go looking for the Scout Dana 300. If you can’t find the Scout 300 you can use an adapter kit from the Texas bolt pattern to the circular Jeep Dana 300 bolt pattern, but you may need to change the output shaft of your transmission and change your driveshaft lengths.
Q: I recently had to have the rearend rebuilt in my ’98 Dodge 1⁄2-ton. I was almost enraged at the price. It seemed to me that two-grand is too much to spend on nothing more than a new ring-and-pinion. I was wondering if I could do that repair myself, as I have had some automotive schooling, but we never covered axles. I was just wondering if there are any special tools needed since I have seen some guys rebuild axle gears on the trail.
A: Sorry, Nathan, if you have to ask then you’re not smart enough to do a ring-and-pinion.
Just kidding. We know how you feel. Setting up ring-and-pinions is akin to automatic transmission rebuilds when it comes to a feeling of black magic, but the fact is you can do your own ring-and-pinion. The trick, just as with basketball and ballroom dancing, is practice. The guy who gets paid to set up ring-and-pinions has (hopefully) the experience to set them up and get a perfect gear mesh after years of practice and hundreds of installs.
The problem is you want to set up your gears, you have never done it before, and you don’t have the years to dedicate to learning the details of a gear install that axles guys get from days upon days of rebuilding rearends. Don’t fret. First read the book Differentials by Jim Allen and Randy Lyman. It’s available from Randy’s Ring & Pinion (www.ringpinion.com), which also sells a complete line of tools and gauges to set up your ring-and-pinion, such as pinion depth tools, dial indicators, bearing pullers, and setup bearings.
If you take your time, follow the instructions, and double-check everything, you can set up your own gears, but the cost of the tools, parts, and install kits as well as the time to get it done right may make you reexamine the “expense” of having a shop do it for you.
30 Low-Budget Issues
Q: I’m a low budget Jeeper and I have been breaking my YJ front axles regularly and wearing out unit bearings frequently. I’ve done some searching on the web and found that I could put XJ or TJ axles in my housing to get the larger 760 size U-joints, but I would still have the unit bearings. I was looking for a better answer, bigger U-joints, bigger ball joints, rebuildabe bearings, and lockout hubs. Is it possible to put Dana 44 outers onto my Dana 30? I know lots of people would say to just put a Dana 44 under the Jeep, but I already have a locker in my Dana 30 and I don’t want to lose ground clearance.
Grant & Lisa Brower
A: Yes and no. You can put a Dana 44 knuckle on a Dana 30, but not your Dana 30, only those in CJ-era Jeeps with open knuckles, not the newer YJ and TJ-era Dana 30s. However, you can get these Dana 30 knuckles from Reid Racing Inc. (www.reid-racing.com/DANA30).
These allow you to upgrade to a removable spindle/rebuildable bearing hub setup from an earlier Jeep or Chevy with a six-bolt spindle, but this means you can only get 5-on-51⁄2, 6-on-51⁄2, and 8-on-61⁄2 bolt patterns. Your YJ is 5-on-41⁄2, and you’ll need different wheels for the front, and then your rear axle will not match the front. Cost is $260 per knuckle plus all the spindle, hub, brakes, stub shaft, and so on, meaning it is not a low-budget Jeeper upgrade.
Q: I have an ’02 Nissan Xterra, standard shift, four-wheel drive with auto hubs. I would like to tow it using front wheel dollies. I have asked the dealership and others about this and am getting different answers. It has the VG33 engine, five-speed tranny, and the box that is 2H, 4H, N, 4L. The front wheels will be about 12 inches off the ground when on the dolly. The owner’s book says I need to leave the transmission in N and the transfer case in 2H. Do I need a driveshaft-disconnect to keep miles off the odometer and keep the gears from spinning? I was also told to put the box in N and all would be good, however that’s not what the manual says. Will I need some kind of auxiliary oil pump to the transfer case and transmission as it is being towed to keep the gears lubed?
A: Follow the owner’s manual. If you put the transmission in neutral and the transfer case in 2-Hi, this will keep the transfer case gears spinning and throwing oil to lubricate the case. If you are worried about miles then you should probably pull the rear driveshaft altogether, but following the owner’s manual should be sufficient.