|[an error occurred while processing this directive]||Short Cuts|
|The 38.5s look huge next to the 35s.|
|The transmission adapter, the Klune V, the transfer case adapter, and the transfer case.|
|A new transfer case skid plate and cross member was built.|
|The Klune V lever and the transfer case twin stick shifters.|
|The Jeep sitting on some 38s!|
By Steve Friend: Member of West Coast 4 Wheel Drive Club, Inc. - 7/3/02
Back in Sept of 2001, my wife and I, with some friends, headed over to do the Montrose, Co. trails. We meet more friends there that were coming from Utah, Colorado, and Iowa. This was the first time that I had could see how really low gears work and the benefit of 37-38.5" tires. The Montrose trails are very different than a lot of trails. I think because they are not necessarily built like the Hammers trails, but are made by Mother Nature. The rocks are large and round. And there is water under them, at least there was for us. I am not making excuses, just comments. As you might guess, I had some difficulty. Where I normally walk over things, I struggled and was constantly hung up.
My Jeep is a '79 CJ7. I had a 4" National Spring Lift, with 1" body lift, 35" tires, 10" Steel Chrome rims, so I was up there in height, I thought. My Tcase was an IH300 from a Scout. My crawl ratio was 72:1. Well, after seeing what 100-150:1 gears can do, more lift, and the larger 38.5 tires, I was hooked. I had to do something.
So, on the way home, I stopped by Alcan Spring in Grand Junction and basically ordered my 6" lift. Then, when I got home, I visited with Jason at Tri County Gear in Pomona, Ca. Jason spent some time with me going over gear change options. I had made up my mind for a 4:1 in the Tcase, but by the time I was done, Jason had me into a Klune V under drive. He said "I know you Steve, and what you get into. Trust me on this". Gotta love him :). One thing that sold me was the option of being able to engage my low gears or not. This was going to be a big project and meant all of my custom Tcase fabrications, drive lines, shifters, and who knows what else were going to have to be changed. I was also concerned about the Dana 44 front universals. Those large tires were going to add a lot of stress to those little guys. And, I can hardly steer the rig now with the Detroit engage. I was curious if the 1" less width tires but 3" taller would be harder or easier. But I digress.
Lift and Tires
The first thing to install and try out was the lift and the tires. The new Alcan springs arrived about 2 weeks after I ordered them, and the tires about the same time. Of course, you cannot have new tires without new wheels, and my wheels were pretty well thrashed anyway. So I ventured into the unknown with aluminum wheels to try to keep the weigh down. When I went to pick up the 5 tires and wheels, they completely filled the bed of my Dodge pickup, 3/4 ton. Wow. When I got them home, I weighed them to see if I had matched the weight of my 35"s. As it turns out the 38.5"s mounted on aluminum wheels weigh the same as the 35"s on steel. Nice. Still darn heavy at 110 lbs. each though.
Installing the springs was pretty straight forward. Of course the U-bolts were too long and the nuts were trashed, but that is common with changing springs. I finished in time to do an easy run out to Morongo Valley Days, after being invited out by Harry Robinson from Link Arc and Premier Power Welder. The Jeep did really well and I was about the tallest out there. My wife and I had to learn how to get into this beast as it was tall. I never felt top heavy and the springs performed fantastic. The ride was really nice and stable. And, I only rubbed a bit on the rear quarters, so new TJ flares were going on and some cutting of the body was going to happen.
Installing the Klune V.
All of the adapters, Klune, etc arrived and was time to start. After all was said and done, the length of the drive train grew 10.5".
The installation for this phase was going to be significant with some pretty interesting re-engineering of the skid plate, rear engine (tranny) mount, anti-torque bracket, linkages, etc.
Acme and included an intermediate shaft. This adapter was a bolt up and no problem. Fitting the Klune V to the adapter is actually pretty kewl as you can use the Klune to clock the Tcase to most any angle you want. I wanted it as flat as possible. Then, I needed an adapter from the Klune to my Scout Tcase. This was provided by Klune Industries and again was a bolt up and included the intermediate shaft. Now, I had to play with various patterns of skid plate designs, starting with the obvious and trying to use my existing one. Quickly, it became obvious that this was not going to work. I worked and worried about this phase until I decided to try a little work strategy and "step out of the box" and think of some non-traditional means of protecting the Tcase as well as supporting the transmission. I ended up using some 1/4" thick, 8"wide by 2" construction channel suspended frame rail to frame rail. I then ran another section of this same channel forward to capture the transmission mount, using two 1" thick rubber pads (like body mount pads) as the cushion between the mount and the channel. This section ended up about 8" long. After welding this together, I dropped the skid plate about 2" until I had a reasonable amount of droop for the driveline. After everything was mounted, I pulled the assembly down and using my plasma cutter, I narrowed the 2" sides down to about 1". I then drilled some 2" holes in the bottom of the channel to provide drainage and to lighten it up.
For the Anti-Torque bracket, I used some 2" angle and captured 2 of the Tcase mounting bolts and came out parallel to the skid plate. I added two more of the rubber cushions top and bottom of this angle, tightening a through bolt just enough to keep get the bracket, skid plate, and the cushions in contact.
Now for the shifting linkage. I run the Currie Twin Sticks, I had to provide shift rods from the shift levers back 10.5" to the shift rails on the Tcase. I machined two flats on one end to fit into the transfer case levers and then two more flats at the levers, only I clocked these flats to ensure that the levers were running straight up through the floor. I did the same for the primary mount for the levers.
The Klune comes with a cable shifter that can be mounted to any convenient position in the cab for shifting the Klune into or out of gear. I decided to mount it to the front of the Tuffy center console. It was strong enough and the sloped front face was perfect for this mount.
I worried about all this new torque and these large tires on the front axle universal joints. I knew I was going to break them, even though I was running the best of the best in the stock design. I finally contacted CTM about picking up a set of their new Billet Design universals. Man, these things are beefy. I installed them and have not had one bit of trouble since.
Now it was time for the trial run. We headed out to the Hammers to try a ½ day run across Aftershock. I played with all the gears and all of the shifting combinations. I had to make myself a cheat sheet to see what gear I could get into. See my options!
|T-case HIGH, Klune High||Crawl Ratio|
|T-case HIGH, Klune LOW||Crawl Ratio|
|T-case LOW, Klune HIGH||Crawl Ratio|
|T-case LOW, Klune LOW||Crawl Ratio|
I found that the 94:1 is a terrific gear, for most moderate stuff, and then shifting out into the 71:1 were my most used gears. But, there are a couple of nice obstacles on Aftershock when I dropped to the lowest ratio. The first time, my wife was watching my face and said I had the biggest smile across it. I felt like I was cheating, it was too easy to take the obstacle, and let the big tires and grip do their thing. Going very slow is great! I nary slipped a tire.
The next day, we did Outer Limits. This is one of the tougher of the tough trails at the Hammers. I had 13 rigs behind me by the time we made the trail head. I made it over the trail without a hitch, no damage, no worries. That could not be said for a lot of the rest of the group as we had broken tires, axles, birfield joints, drive lines, universals, etc. broken by the time we crawled out late at night. I, on the other hand, could not be happier.
But, with all this, and after several other trails, some hard and some not so hard, I ran into two problems. One was that I kept going through rear universals. We finally figured out the my rear end output to the driveline need to be rotated 4°. The other was that I had a heck of a time steering. Time for a long range trip. Good news, no bad universals, anywhere. Bad news, I really broke bad going across Judgment Day out of Black Canyon City, Az. I completely tore the output gear out of the top of the Transfer Case.
We finally figured out that during the process of trying to steer the Jeep, going forward and back 12" at a time, I finally locked up the rear drive shaft universal through some tremendous axle wrap, and transferred all of the available torque to the transfer case. Man, when it broke, it made quite a loud. Jason said he had seen this in the past in some of the competitions he has attended and that he is making a new Anti-wrap bar that welds to the rear end, keeping the axle inline with the drive line, while still allowing the rear end to articulate.
New and Unexpected Phase
|Seriously shattered transfer case.|
|A CV rear driveshaft was used to get the proper universal joint angles.|
|Testing on the trails.|
Well, the Tcase was toast. And the Scout cases are very hard to find, so, my friend John Brezezicki gave me his spare Jeep D300 and I had Jason go through it, sealing it and adding the newer high strength output shaft. Of course I again had to modify my skid plate, but only a little this time. The shifting rods, rails, and mounts were all reusable too.
In the mean time, I decided to step up and improve the steering. I contacted Brad Kilby of Onboard Air. He has just started working with Lee Manufacturing in Van Nuys. Lee has been building and modifying steering components since Henry Ford was in business I think. All I saw them do was steering components, from very small boxes and pumps to Semi size. They rebuilt my pump to put out 1500 psig at idle (normally 1500 at speed), rebuilt my steering box and added two -6 pressure ports, and then made me a ram of the length that I needed. I made a clevis on the axle differential cover that uses 3 of the differential cover bolts to help hold it in place. I then used the steering stabilizer bracket that secures around the tie rod for the ram portion, modifying it only to add some strength to keep it from bending. It works.
Is that enough? No, of course not.
I added the anti-wrap bar from Tri County and attached the end of it through a shackle type of arrangement to the skid plate. I then ordered a high angle drive line out of Drive Shaft Superstore, http://www.arizonadrivelines.com/. This thing is way kewl and I don't expect to see any trouble with it. Oh, I forgot, along the way, I found out that these new tires work well at about 6-7 psi. And I was worried about them falling off the wheels, so I sent the wheels through Brad Kilby again, to OMF to get bead locks installed. No more worries in that arena.
Phew, that is enough. Now, to go out and wheel and not worry, I hope.
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