Tractech’s Gearless Locker

Serious traction for serious situations, every four wheeler’s dream. I’ve personally had experience with three different models and makes of lockers in the past. With all honesty I can say the Detroit Gearless Locker has them all beat for smoothness, handling characteristics and noise reduction. The locker came well packaged and included a video, well written installation instructions with good clear illustrations and an owner’s manual. The video was excellent and informative although it was a little blurry in some places. The instructions were understandable, clear and followed the pictures from the reader’s view. All required bits and pieces were in the box including a bottle of Tractechs Gearless Locker Fluid. Overall, the instructions covered most of the necessary installation instruction and anyone who has ever done their own differential or axle work could most likely handle the install with a few additional tips.

Gripes? Yeah, we have a couple. Not included in the kit is a new split pin (retaining pin) for the center pin. Not a big deal as the old one can be re-used but it would certainly make a nice addition if, like myself, others are inclined to use the opportunity while the case is open to do some basic preventative maintenance replacing old and worn parts and pieces. We took the opportunity to replace the seals and inspect the bearings and gears for signs of wear and it sure would have been nice to pop a new split pin in at the same time. Another minor annoyance (not mentioned in the installation instructions) is the possibility of casting burrs or corrosion on the carrier interfering with the insertion of the locker into the carrier. At first glance, it just doesn’t fit the carrier. Anyone unfamiliar with this kind of install would be inclined to send the unit back assuming it is the wrong unit for the application. On second glance you’ll probably find some minor casting irregularities that may require filing. Just for interests sake we rummaged around the garage and a few friend’s garages to find some identical carriers. Sure enough all of them had casting burrs of varying degrees. A careful filing and thorough cleaning remedied the situation. Special thanks go out to Tractech for including two extra springs. It is amazing how far the compressed springs can fly and how difficult they can be to find. Overall the locker was machined beautifully, the kit was well packaged and the instructions well thought out and worded with plenty of pictures and diagrams. Of note, always have your owner’s workshop manual with you, as each installation will be as different as the 4×4 it is being installed within. In this case we opted to install the Gearless Locker in the front of a 1980 CJ7 that has had 1978 International Scout Dana 44’s swapped in front and rear and manual locking hubs. In this way we were able compare it against the Detroit Soft-Locker currently in the front differential of my 1990 YJ Dana 35 with regards to on and off-road personality. I would also like to mention that the Tractech web site is a wealth of information concerning lockers and tech. tips.

TESTING:
The Gearless locker has a much smoother operation, virtually noiseless with no tire chirping or wheel drag. The only handling changes were noted in 4wd with good positive lock up and a wider turning radius. The positive traction in low range 4wd was impressive and handling affected similarly to the Detroit Soft Locker. I believe this is a very good choice for a front diff. Installation because of its smooth operation and quietness. One must always keep in mind that any locker installed in the front differential of any vehicle will affect handling characteristics, in particular steering. Be prepared for stiff and unresponsive steering and those 60-point turns we like to call “locker corners”. For tight situations you can always unlock your hubs, or in the case of a vacuum controlled shift motor, install an in cab manual disconnect like the “Rock Lock”. Frankly, in my own experience, the gains in off road traction make it all worthwhile.

Owing to the fact that it is winter time in Canada and we now have very few visible rocks and more frozen, snow covered mud than not, it has been difficult to really put this locker to the test. The real test will come spring thaw when we all hit the trails for another season of off roading. Thus far we have been impressed with the traction gained in the snow and slush although, with the ice underneath, the Jeep tends to slide-slip and, naturally, the turning radius is slightly although almost unnoticeably wider. This is not the result of the Detroit Gearless Locker but a pretty well standard response for a front differential installed full-time locker in this climate.

Getting serious traction in snow and ice can be a challenge at the best of times. Sometimes too much traction can be as challenging as too little. We drove the CJ around town for the better part of a week with the hubs locked in 2wd. We were impressed with the smooth virtually noiseless operation and that the steering on pavement was not adversely affected. We then took the Jeep on some no winter maintenance roads to see what it could do in deep snow. The tires dug in and down until they hit the frozen mud under the mounds of snow. The front locker literally pulled the CJ up a very steep, slippery and snow covered hill. We were impressed.

Our take on the Detroit Gearless Locker… two thumbs up! This quiet, unobtrusive, easy to install, maintenance free locker gets raves reviews from this driver. As it is time to move over and let the snow-machines have the trails for the winter I will re-review the Detroit Gearless Locker in action when we are able to hit the trails and really put it to the test. I can hardly wait for spring thaw to test it out on some serious rock and mud.

NOTE:
The gearless locker is designed specifically for light to moderate trail use and not for any hard-core or extreme usage. If you have a heavy foot or plan on doing any serious 4-wheeling, the Detroit Gearless Locker isn’t made for this and will not stand up to the punishment. 

Installation:

Editors note* This particular installation is specific to a 1980 CJ7 with manual locking hubs and swapped in front and rear Dana 44 axles from a 1978 International Scout. I have not covered removal of the locking hub assemblies and brake components in detail, as this information is available in your service manual. I do not believe that you should attempt an installation of this magnitude without at least some prior experience or knowledge of your axle and hub assemblies.

First and foremost we opened the kit and ensured that all the parts and pieces were there as listed. We then spent some time viewing the video and going over all the instructions. Armed with the installation instructions and the service manual we headed out to the garage to set up some really good lighting, as we would be working with small parts. We opted to forego the compressed air just to see how hard this would be to do with hand tools and sweat equity. After assembling an arsenal of tools we positioned the Jeep on appropriate weight rated jack stands and blocked the wheels. We removed the wheels, calipers, disc brakes and backing plates to get full access to the axle shafts.

Before removing the axles Vic and Phil loosened the differential cover bolts and started to drain the fluid into a drain pan. It was necessary to gently pry the cover loose to let the fluid escape around the gasket. The brakes and hub assemblies were then removed and set aside. We took this opportunity to inspect the ball joints, braking/steering components and axle end U-joints for wear or needed maintenance. Once the hubs had been removed we gently worked the axles back and forth to loosen them from the seals and pulled them straight out. Unfortunately the axle tubes were filled with good old Ontario mud which necessitated a thorough cleaning and replacement of the inner axle seals. The axles were in excellent shape with no scoring or bluing; they were cleaned carefully, wrapped in clean shop rags and set aside in a safe place. Just to be sure we counted the splines on the axles to ensure that they matched the splines on the locker which was probably a good idea as we didn’t want to get any farther and find out we had the wrong locker for the axle.

Turning our attention to the differential cover, we removed the remaining bolts and gently pried the cover off to allow the fluid to completely drain. We checked the condition of the gear oil watching for milkiness, sediment and pieces of metal. Milkiness or sediment should be your clue that the seals and gaskets need to be replaced and that it is likely your carrier will need to be cleaned out very well to remove any debris or corrosion. The presence of metal means you have a more serious problem that may require replacing the ring or pinion gears. Personally and most likely because I’m something of a preventative maintenance advocate, I would recommend having all new seals available as this is an excellent opportunity to replace them. While waiting for the fluid to drain I cleaned the old RTV sealant from the cover and wiped the cover clean. I guess I was lucky that day, I got all the easy jobs because I was taking notes.

As this was a front axle install and this CJ has a Spring Over Axle Conversion it was a simple matter to crank the steering hard over to the right to allow us clearance to be able to get the carrier around the drag link when we removed it. In a stock CJ or YJ it will be necessary to remove the drag link. Using a pry bar, Vic gently loosened and slid the carrier assembly out far enough to allow Phil to remove the bearing end caps. An extra pair of hands were most helpful at this point in time to remove and mark the bearing caps right and left to ensure that they would be returned to the original position. The bearing cups were removed and set down beside the corresponding end caps in a clean space (don’t forget to mark the end caps with a punch, marker or some other way so that they go in EXACTLY the way they came out).

While protecting the carrier unit with clean rags we clamped the carrier/ring gear assembly in a vise. It is important to mark the position of the ring gear in relation to the carrier to ensure proper set up when reinstalling the carrier thus avoiding added time and expense in setting up the gears, something I trust the professionals to do! In this case we used the date stamp on the ring gear as a reference point and, with a punch, marked the carrier. The carrier bolts were removed and the ring gear was gently worked away from the carrier using two equally spaced bolts and light taps with the hammer to loosen. The carrier was lifted out of the ring gear and the ring gear set to one side in a clean place. On inspection, the gear was clean and showed no signs of wear. Discolorations on the gear teeth would have indicated excessive friction causing heat to build up and blue the metal.

The retaining pin (split pin) was gently knocked out of the cross pin and the cross pin removed The spider gears were removed taking special care that all of the shims were removed as well. This is an important step and you have to be careful to get them all as they are hard to see. Vic set about cleaning and inspecting the carrier unit for corrosion or damage while Phil finished cleaning out the now empty differential and axle tubes.

Everyone’s hands were washed to ensure that grease, oils and dirt did not contaminate the clean and new parts we’d be working with next.

With the carrier still in the vise in a vertical position we greased one hub sleeve with white lithium and fit it squarely into side gear pocket of the carrier along with the thrust washer. We then inserted one of the side gear spacers into the clutch housing and slid the assembled unit into the carrier. Following the instructions we were careful to ensure that the disc pack remained firmly engaged. This step is very well documented in the instructions with easy to read and understand illustrations. We then attempted to install the second half of the assembly only to discover that the unit wouldn’t fit. After much grumbling and measuring we realized that the carrier had a number of casting irregularities. We scuffled around in the garage and a few neighbours and friends garages to find identical carriers. Most of them also had casting burrs. We decided to remove all of the parts assembled thus far and file the burrs and corrosion off the carrier edges using a half round mill file. This done and following a very careful cleaning of the assembly we re-installed the hub sleeve, thrust washer and the first half of the locker assembly. Using the special side gear puller tool that was supplied in the kit we installed the second half of the locker without the remaining side gear spacer. Vic turned the carrier horizontally in the vise while Phil supported the components. Although the directions don’t mention this, be sure to line the halves of the locker up so that the dowel on the one half lines up with the slot on the opposite half. We weren’t smart enough to do this on our own and it took us a little while to figure out why the side gear spacer wouldn’t fit. Once we aligned the slots and dowels on the two halves of the locker we were able to slide the side gear spacer through the v-slot in the clutch housings and into place in the second clutch housing. We then used a screwdriver as a wedge to keep the two halves of the locker separated while we prepared to install the springs. Taking a set of crescent shaped pliers we compressed the springs to their solid height. Eye protection is a must at this point as those springs pack quite a punch if they slip out of the pliers. Fortunately the kit contains an extra set of springs should any of the springs make a hasty get-a-away in a crowded garage or if they get damaged during installation. (We managed to damage one of the springs in our first attempt to insert it into the slot.) The pliers, with the spring compressed, were lined up with the slot in the locker assembly and knocked into place using the old cross pin and a mallet.  It will take a good couple of hard knocks to get them properly seated in the pockets on either side of the assembly. The locker was rotated to line up the V-slots in the clutch housings with the cross pin hole in the carrier and the new cross pin through the carrier housing and secured in place with the split pin (retaining pin). This kit does not include a new split pin so be sure you salvage the old one.

The assembly was securely clamped in the vise and lining up the date stamp on the ring gear to the punch marks on the carrier the bolts were torqued to manufacturers specs. The carrier was now ready to be reinstalled.

The inner seals were replaced because of the mud and dirt accumulated in the axle tube and the carrier reinstalled ensuring that the bearing end caps and cups were re-installed in the same side that they were removed from. The recently cleaned diff cover was given a new silicone gasket and reapplied, again torqueing the bolts to manufacturer’s specs. We took the opportunity to go for lunch to allow for some set up time for the silicone. Returning from lunch we added the Detroit Gearless Locker Silencer Fluid as supplied in the kit and topped up the diff with gear oil. With the CJ up on stands we could barely contain our excitement as we performed the installation test as outlined in the Tractech instructions. Everything was working out as planned, they locker was quietly engaging and disengaging as expected virtually soundless and exceptionally smooth. It was time to roll the Jeep out of the garage and test it out in action.

The Gearless locker has a much smoother operation, virtually noiseless with no tire chirping or wheel drag. The only handling changes were noted in 4wd with good positive lock up and a wider turning radius. The positive traction in low range 4wd was impressive and handling affected similarly to the Detroit Soft Locker. I believe this is a very good choice for a front differential installation because of its smooth operation and quietness. One must always keep in mind that any locker installed in the front differential of any vehicle will affect handling characteristics, in particular steering. Be prepared for stiff and unresponsive steering and those 60-point turns we like to call “locker corners”. For tight situations you can always unlock your hubs, or in the case of a vacuum controlled shift motor, install an in cab manual disconnect like the “Rock Lock”. Frankly, in my own experience, the gains in off road traction make it all worthwhile.