As part of my preparations for the Divide Ride '98, I installed a Lockright Locker in the front differential of my '77. Two weeks earlier I had told my friends at dinner (after a pre-run for the 'Ride) that I was putting a T19 4spd in, a twin-stick'd Dana 20, and a Lockright. Apparently they didn't all fully believe me. :-)
I ordered the Lockright from Desert Rat for $250. I managed to get my hands on it Friday night. I removed the T15 that weekend, and I had to wait 'till Monday to get the clutch parts reconditioned, so I started in on the front differential.
I removed the cover and drained the gear lube. This was my first time inside a differential, so it was interesting.
I noted that the cross-shaft would NOT come out with the diff still in the housing, so it all had to come out. I jacked the front end up and removed the tires, the disc brake calipers, the locking hubs, the rotors.. and then gave a slight pull on the axle shafts and pulled them out a bit.
I then removed the main bearing cap bolts and caps, carefully make sure to note which direction and side the caps and bolts went back in.
I then had to get the differential out. At first, I tried a pry bar and gently applying pressure.. no dice. I tried two bars.. no dice. I needed a really long pry bar and/or some help on this one..
Finally, I became a bit frustrated. I had the pry bar hooked under the ring gear, and I gave it a good solid kick.. POP! Out came the differential. A little more prying and then I was snaking the diff assembly out from housing and around the drag link and tie rod. Whew.
Installation of the Lockright then required me to remove the ring gear from the carrier. I noted in my IH service manual that it calls for the ring gear bolts to be replaced any time they are removed. I asked around locally, and everyone said to simply reuse the old ones.. they didn't even have any new ring gear bolts to sell me..
I removed the ring gear, then removed the cross-shaft and the side and spider gears. I followed the Lockright installation instructions, re-using the original thrust washers, using grease to hold the pins and springs in place.. I also used a 4x4Power article for a little additional reference material.
The locker installed into the diff case easily. I then reattached the ring gear, and went back to the Scout for re-installation.
I pushed the diff back into the housing in the appropriate location, and pushed n' pried a little to get the bearings into place. Here is where things started to go wrong. I didn't read the shop manual closely enough.. you're supposed to use a housing spreader on this part, too..and you DO NOT use the main bearing caps to pull the bearings into place! Of course, I figured this out after I hit 50ft-lbs of torque with one of the cap bolts only halfway in... CROSS THREADED!! I wept. I used my hammer to pound the differential in all the way, and then double checked by installing the axle shafts.. they required a little help from my hammer, too.. it was a tight fit.
With the diff seated, I tried to torque the main bearing cap bolts down again.. no dice. I had messed up the threads. I ran to the hardware store for a couple shorter Grade 8 bolts, hoping there was enough good thread to torque it down.. nope.
I wept.
I stopped for the night, and turned to my friends on the IHC Digest for help. Several scenarios came up at work Monday.. try re-tapping the hole and see if it works. Drill it out and Heli-coil it. Have the housing welded up and re-drilled. Or scrap it all. I priced out the availability and $$$ of my various scenarios.. hoping the re-thread would do it.
I got home from work with a new 1/2" 13tpi tap, and ran it through the bolt hole.. carefully cleaning out the material that came out with the tap. Then the moment of truth.. I put some red Loctite on the bolt, and carefully torqued it all the way in and to the necessary 50ft-lbs. YEE-HAW!
I did the Lockright test to make sure it was locking and unlocking properly.. yup. Put it all back together and fill with gear lube.
I, naturally, had to test my modifications before I headed out for the Divide Ride.. so Wednesday night, after the stock transfer case was finally reinstalled, I took my 4spd and locker for a test drive over Mount Ascension.. the locker was definitely noticeable on the steering and in traction. The 4spd helped out with lower gearing that made some previously unscalable trails easy. I quickly turned around, headed for home, and then off to the Divide Ride!
The locker came in handy a few times on the 'Ride.. it made things a bit easier.. particularly the deep mud pieces. In one location, I had rammed the front diff against a big rock in a mud pit. I got strapped rearward, and then tried again, but I was off to the side of the rock and ready to hit it again.. I turned my wheel hard to the left, and asked my spotters if I could get on it.. they didn't think so.. but the locker put that tire right onto the rock and I was up and over it.
It also helped out while driving Holy Cross City during the '98 Rocky Mountain IH Rendezvous.
Back to the locker install.. I was telling my friend Mike Kelly about my ordeal when I got the Divide Ride.. and I mentioned torquing to 50ft-lbs.. Mike said, "50? You want more like 80 buddy." HUH??? A quick check of my IH Shop manual's REAR END section, and yep..80 for a '44.. I was reading the front axle section, and since my service manual is for a '72-75, it lists the Dana 30 front axle.. oops.
After the Divide Ride, I had to open the differential back up, remove the bolts, and re-torque to 80ft-lbs.. I reapplied red loctite.. and you can't imagine how much I was dreading each 5lb increment click on the torque wrench.. just waiting for the threads to strip.. but they didn't. I managed to get my full 80ft-lbs of torque, and all was well.
-Tom