UPDATED 05-22-07:
For those that have followed this thread you are aware that I originally had the gas tank chopped in order to accommodate the additional length of the double transfer cases. The process of modifying the gas tank resulted in a loss of ~1.0+ gallon of fuel capacity. Well I'm glad to say that we figured out an easier way to modify the gas tank and the resulting fuel capacity loss is negligible.
After installing and running the Inchworm doubler and Lefty transfer case for a few months I decided to see if there was a way to recover the lost capacity. I talked with a number of plastic fab shops and decided that the HDPE tank could be heated up and reshaped. I purchased a new gas tank and some heat guns and went for it. The result is that I was able to push the front corner of the tank in about 1.5" so that it would clear the transfer case housing. It worked like a charm and I now have relatively normal fuel capacity. I estimate that I have lost a little capacity, but nothing noticeable.
This method of modification will only work with the Inchworm Lefty transfer case and doubler and not your stock transfer case and a doubler. The stock transfer case is longer than the Lefty transfer case and would require the tank be severely deformed in order to fit. even then I doubt you could reshape the tank enough to make the stock case fit. The Lefty case only requires about "1 more room to fit.
For those of you contemplating a crawler, but concerned about the gas tank mods, this is much easier to do then chopping and welding the tank. However, yes you are still playing with the gas tank and if that make you uncomfortable, then this mods not for you.
BEGIN ORIGINAL THREAD:
I dropped off my FJ Cruiser a few weeks ago with Jim at Inchworm to have it slowed down a little...
Jim wanted to do some testing/prototyping on an FJC with his new gear driven tcase and adapters and I wanted lower gears. I had their new driver side drop geared transfer case (a.k.a. Lefty) along with a crawl box installed. The front reduction box has 2.28:1 gears and the tcase has 5:1 gears. The AT FJC's stock crawl ratio is 33:1, with the Inchworm setup I am now at 168:1. Also installed are a set of triple sticks that come up through the floor in the original tcase lever position, so no cutting was necessary. Jim also did a test fit of just the geared transfer case and it will install without modifying the gas tank or drive lines. The geared tcase is a great solution for folks that want to run lower gears, but don't want/need double tcases.
And lastly, but certainly not least, Jim and him team are great to work with... I am very pleased with my experience and will do more business with them in the future.
Here are a few pictures of the setup as it was being installed. I will post more information and pictures once I get my FJC back this weekend.
Gear driven transfer case plus the reduction box and adapters:
In the picture below you can see the FJC exhaust cross-over pipe and how flat it comes from the factory. I will be moving the cross-over pipe now that I have more room.
The belly of my FJC is now just about completely flat. Remove the factory cross-member and re-route the exhaust cross-over pipe and it will be flat:
The gas tank in the FJC's is very close to the stock tcase and must be shortened to install double cases. A plastic welding company was able to shorten the gas tank by 3". The 3" is equates to 1 gallon less capacity, which to me is worth it for the lower gears.
Chopped gas tank:
Clearance between tcase and gas tank after install:
Re: FJ Cruiser geared tcase & crawl box by Inchworm
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