4x4 Icon - Detroit Lockers, Superior Axles and Gears

Background
I would like to say that I planned a major change to my axles, differentials and gears. The fact of the matter is that I wanted to make some changes but I had restrained myself, due largely to cost. I was beginning to attempt more difficult terrain, and with the addition of the winch, was more willing to place myself in positions that would lead to difficult recovery, were I to rely on straps and Hi-Lifts alone.
This of course meant putting more stress on my drive train. Somewhere along the way, it happened: I knocked off a couple of spider gear teeth. I noticed it after my Oak Ridge trip with the VA4WDA in October 2002. While conducting my ritual cleaning of the Jeep, I noticed a small leak in the rear cover. I was quick to assume that this was caused by peeling back the diff cover on a rock. I thought I would be fixing the cover and putting it back together. I was wrong. When I removed the cover I discovered a hole punched from inside, looked up and saw the spider gears... Crap! This was not on my list of things to do...
Still thinking I was going to get off cheap, I took it to the dealer for a second opinion. Not good. They told me that the entire contents of the axle housing would need to be replaced, axles, differential, ring and pinion, and of course all the bearings, seals, etc. They quoted me a price and my jaw hit the floor. I opted to pay them their minimum fee for the estimate, have the diff cover hole brazed closed, and take the Jeep home for some contemplation. Fortunately it still worked and I was able to drive it for several weeks while I decided what to do, and then assembled the parts to execute my plan.
Based on the price quote from the dealer, I determined that I could do more for less. I priced lockers, axles and gears - got the best price from Quadratec, and found a mechanic that would do the work for a price that I could handle, and still less than what the dealer wanted to do just my Trac-Lok. The plan was put in place. I would install a Superior "Super 35" kit with the Detroit NoSPIN locker in the rear Superior Ring and Pinion gearing to 4.56's Detroit TrueTrac up front while I was in there... At the same time that this was going on, one of my friends was installing ARB's front and rear, and my other friend was installing a Currie/Ford 9" rear with the same Detroit NoSPIN. Both did Slip-Yoke eliminator kits and 4.11 gears. Our little stocker clique had morphed practically over night!
Detroit TrueTrac
That seemed simple enough. I shopped price hard for several days and then found the most flexible price-matching place (Quadratec) and placed my order for a ton of stuff. Then I started to wait. After a few days the Super 35 kit, gears and rebuild kits arrived. It took another two weeks before I called to find out what had happened to the TrueTrac. It turned out that the order had gotten mixed up and it was on back order - the wrong unit on back order! Well the good news is that they fixed the mix-up and a week later (Arrrghhh!) the correct unit arrived on my doorstep. It was an agonizing wait, especially since the rear end was making loud metal crunching noises!
So off to the shop it went. I know my limits. I have done entire chassis, comprehensive restoration of body work, painting, and even glass replacement. My interior reupholstery skills are good but I would not do a full interior for a show car. I have also done fairly complex engine work. My understanding of differentials is sufficient to know what the parts are, how they work, and what the symptoms of component failure are. But I do not have the tools and experience to rebuild them. I rented a super cheap car and started my wait. I didn't have to wait long. I called a couple days in to my wait and got some bad news: the axle housing had been damaged where the differential bearings support the carrier in the case. I would have to replace my otherwise straight axle housing with another. My friend with the Ford/Currie 9-inch had left his behind in case I needed it, and soon my Super 35 kit was assembled inside his old rear end and bolted back up to my Jeep. I also had to do some foot work on the ABS tone rings. They are not sold separately, and had to be pressed off the old factory axles and pressed on to the new Superior axles. The mechanic told me that the removal from the factory axles cost him an attachment on one of his presses, but the installation onto the new axles was easy.
My friend with the ARB's drove me over to pick up the Jeep. We hung around for a while watching the little details be finished up and then I got my Jeep back. First of all, anyone contemplating a Detroit Locker needs to get a ride in a Jeep that already has them. I don't mind the quirky behavior that my Jeep now has, but it sure isn't for everyone. The rear end wiggles around and the wheels do all sorts of things when the diff is adjusting itself. I am quickly getting used to it but do not cherish my first couple of snow or ice storms... My ABS light came on right away and is still indicating some sort of malfunction. I am hoping to troubleshoot that very quickly and pray it is not something that will require messing around with the axles...
On-road Impressions Dry Pavement: I had read about all the special considerations that must be taken into account when driving a vehicle that is equipped with a locker such as this. The Super 35 kit came with a sticker that lays it out in plain English -see the information printed in the manual or click the image to the right: All of this makes it pretty clear that things will be different. So I am not surprised to feel the rear end shimmying, and to hear clicking and popping. None of it is as bad as I would have expected from the stories I have heard. I played around with it quite a bit and quickly got the feel of it, and learned what to expect in various conditions, and how to respond. In many cases, you can actually make the locker behave a certain way, and use that to your advantage. For example, on turns, the locker has a tendency to create understeer if you press the gas, and quickly changes to oversteer if you let off the gas. With this knowledge, you can make steering corrections with the gas (on dry pavement at reasonable speeds). I would not attempt to use this quirk on snow or ice. Speaking of that...
With snow and ice on the road, things change a little. If there isn't enough traction to keep the wheels from slipping, the locker will not be able to unlock normally. This is supposed to lead to a loss of traction. And indeed it does. I think that people (like me) who are accustomed to driving on snow and ice, will find that they simply have to be even more gentle with the gas and brake than usual, in order to prevent a loss of traction. I am sure that eventually I will encounter a situation where no amount of TLC is going to prevent a loss of traction, but driving it in the snow, I didn't experience any problems.
Off-road impressions... First of all, I still have not had a great deal of opportunity to try them out. But from the first few outings, here are some observations.
	On the German River run, I found there were some things I could do that my friend Hugh with GS/A's and a Trac-Lok could not. However, Carl left his ARB's off and climbed the same obstacle so I think in that case, it was more about tires (TrXuS for me and Carl) than lockers. There were a couple opportunities to try some more aggressive routes and I found that I was able to get through with little or no trouble. I think in those circumstances, the lockers played a part. One was a vertical climb out of a stream crossing. I was able to place one wheel on the vertical edge of the climb-out, and drive up without any wheel slip. As I got to the top, the rear wheels sort of hung up on the rim, but the front wheels continued to pull me up and over. It was interesting to see the Jeep crab side-ways in response to steering inputs, while the rear kind of hopped as the tires rotated. I don't have any pictures but the one of the left shows the general theme of the day - rain, leaves, and cold.
We went out to the wood lot again. Once again, I didn't get any pictures of my Jeep.... Carl, you need to get a digital camera, bud! (Maybe if I stop taking pictures of Carl, he will...? :) The photo to the right shows a stream crossing that ends in a climb-out that is strewn with fairly large boulders. I tried this obstacle before I got the lockers. It took some thrashing and go-pedal to get over it. This time, with the lockers and gears, I walked up and out of the crossing with almost no gas pedal at all - just idle speed crawl in 4-LO-1st! I did have to give it some gas to keep the revs up, but it was really easy to get out. Here, Carl climbs out with the ARB's engaged.
	I finally got a chance to go back home to Massachusetts. While I was there, I took a ride to a popular trail. It took some planning because the local wheelers don't like to give out location info. But I found it anyway, and planned well so that I would be able to get there and back. When we reached the trail, there was four inches of snow on the ground, with an ice base on the rocky trail. It looked pretty intimidating. Click the picture to the left and you will see the rock garden of small and moderately large boulders on the trail to the right and behind the Jeep (and what looks like my Dad zipping his fly...). We crawled it in both directions and had zero problems. This picture does not really show how rough and slippery that trail was. Not a problem - I left it in 4-LO 1st and idled through. I had to work hard to pick my line, but of course, there are some things that lockers just won't do... We didn't tackle the obstacles that day because they were sheer ice - something else a locker isn't going to mitigate.
Bottom Line If you don't have lockers, you may some day want them. If you're just banging around trails once in a while, it might not be worth the money and time you will spend installing them. And if you mainly drive on pavement, you may want to get something like the OX or ARB's. But for the combination of strength, reliability, price and performance, I am very happy with the Detroits that I installed. I am looking forward to more outings where I can experience the benefits of these devices! Update: 8/12/06