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AW-4 Transmission Swap

This page contains those odds and ends comments, photos, and miscellaneous changes for the project.  In other words, I either forgot to include something in an earlier page (20 of them as I write this) or something came along that caused me to change the way I had previously set up something.  So, it gets added here so you get to see it. 


I realized that I didn't have a picture of the center console with the shift indicator installed.  So this is what it looks like when it is all back together. 



I believe I mentioned that my long arm lift makes for a cramped exhaust system along the passenger side of the center skid.  A trip to the local performance shop (same place I got the Parker hose, -AN fittings, etc.) provided the same heat shield covering that Troy had used on a recent V-8 swap.  It comes in a variety of sizes to slide over regular hose.  I picked up the -10 size since I had to get it over the already installed fittings (one would normally slide this onto the hose prior to attaching the fittings) and around a 90 degree fitting.  This heat shield is being used on the fluid hoses for the AW4.  They are close to the exhaust system and the IR heat gun shows that the material does a pretty good job in reflecting away the heat.  The real test will be during the summer when rock crawling.  Price is about $4 per foot (varies with the size of the covering). 



I had a little time today and so I took care of the brake pedal.  ScottK used a stock auto tranny brake pedal on his and it sure made it look factory.  I opted to weld my clutch and brake pedals together.  A good friend said he runs his this way and found it to work better than the factory auto brake pedal.  It was easy to shape the bracket and since I put racing holes in it, I know my TJ will go faster just because of that.   Troy was kind enough to tig it in place for me.  (Did I mention that I suck at welding?)  If you go this route, don't forget to remove the rubber pads prior to welding....else you will have a gooey mess on your hands by the time you are done. 


That is about it for this write-up.  I hope you have found it helpful.  I tried to cover a number of different issues that I ran across and some of the more common ones that most folks usually ask about.


Comments from 1/7/2006:

I sooooooo enjoyed trying out my TJ on the trail today. It was everything I was hoping for and just a bit more.

It was the first shakedown run for me since installing the AW4. While I have rolled several hundred city/highway miles since the install, this was the first day when the t-case was put into 4HI and 4LO and the lockers were fired up.

We ran an easy wash for the first part of the outing. I wanted to make sure my front locker was behaving correctly after having repaired it, installing new axles, and setting up the gears.

The next trail started out with a water fall that is done in two stages. I played on the lower section with the new tranny....basically getting the feel for it with the weight transferred to the rear axle. The top half of the water fall found me on a line that I'd avoided before....hey, the bottom half was a blast so why not push it a little more. I managed 3 tires on the rock and carried one several feet in the air....felt very comfortable doing so. My buddy got nervous and was  volunteering for ballast duty, but I declined....gotta learn where the edge of the envelope is, right? I crested the top and gently laid the carried tire back down onto the rock. Mission accomplished.

Some observations from my first trip out:

#1. I DO NOT regret leaving the 4:1 t-case in the TJ. My buddy has the 3 spd TJ auto in his and he rode the brakes dropping down into the washes while I let the engine braking take care of it for me. I was totally impressed with just how steep a descent one can make with my setup when the engine is holding at 1250 RPM on the steep down-hills. I would not have been happy with stock low range gears.

#2. Not as much heat is generated by the torque converter when those 4:1 gears are doing their job. When I was playing on the water fall, the cooling fan cycled on and off and the temp maxed out at 180F. (mind you, there is no tranny cooler catching air from the radiator fan) When I was just crawling through the wash (no waterfalls), the temp was usually about 150~165F. When the fan did kick on, it only ran for about 20 seconds. The freeway ride, home, with about 80F ambient air temp, had the tranny temp sitting just under 150F.

#3. I had more than enough brake performance to stop myself when in LO range. The 1 ton hydroboost did an outstanding job and I am confident that having it made the trail all that more enjoyable. There is absolutely no feeling of overdriving your brakes.

#4. I didn't drive nearly as much with both feet as I expected I might. Where I was expecting the 4:1 gears to pretty much make forward progress a continuous thing, I found that a medium size rock in front of the front tire left the torque converter just sitting there, waiting for me to give it more gas.

#5. I miss my hand throttle. I felt somewhat lost without it and found myself on numerous occasions searching for it with my finger. Yes, I know it is not nearly as important as it was before, but all those trails with such a good friend will take me a while to adapt to its absence.


Comments from 4/9/2006:

With the tranny pan extending forward of the t-case skid, I needed something in place to protect it from rocks and other things likely to punch a hole in it. 

I finished my new aluminum engine & tranny pan skid this weekend.  It turned out quite well, in my opinion.  Hopefully it will give you some ideas if you decide to make your own skid.

I believe I mentioned that the grommet on the XJ shifter cable was undersized for the hole in my TJ's firewall.  For he past 3 months, it really hasn't been much of an issue....up until spring finally arrived that is.  Now, with day time temps hitting in the low 80s, I can feel the heat from the engine compartment flowing around the grommet.  It makes for a warm right ankle.



Using some thin aluminum flashing, the kind you can get at the local hardware store for roofing work, I cut a hole in it to fit around the rubber grommet.  A slit cut to the center allows one to slip it over the cable.  From there, I worked the edge of the grommet through the hole until I had it all the way through as shown in the above photo.



A view of the firewall hole from the inside of the vehicle.  As you can see, the grommet is undersized.  The aluminum flashing seals the hole very nicely.

To keep everything in place and to make things a bit more waterproof, I applied a generous amount of RTV to the flashing (on both sides of the firewall) to help seal everything. 


Enjoy and remember to TREADLightly! 




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