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Discussion Starter #1 (Edited)
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:
 

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sbechtold said:
The AT FJC's stock crawl ratio is 33:1, with the Inchworm setup I am now at 168:1.
Great info about installing the gear case by itself for lower gears!!!

Gas tank mod didn't look too painful... new tank...now you can mod the old one and sell it to the next guy!


LOOKS AWESOME... Pic of the triple stick inside?

so... how does she crawl?
 

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Discussion Starter #3
MrSammi said:
Great info about installing the gear case by itself for lower gears!!!

Gas tank mod didn't look too painful... new tank...now you can mod the old one and sell it to the next guy!

LOOKS AWESOME... Pic of the triple stick inside?

so... how does she crawl?
Thanks! I get my FJC this weekend, so I haven't even driven it yet, but Jim said it goes REALLY slow now... :cool:
I will post more pics of the triple sticks and linkage setup over the weekend.
 

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sbechtold said:
Thanks! I get my FJC this weekend, so I haven't even driven it yet, but Jim said it goes REALLY slow now... :cool:
I will post more pics of the triple sticks and linkage setup over the weekend.

time to buy an extra 'spare' CV shaft! :D


Congrats... Even I have a bit of FJ envy on ya! My sammi crawls at 114:1 or so right now (low enough for it)... it's fun to go slow! Just watch the gear changing and engine revving... LOT O TORQUE!!!
 

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Discussion Starter #5
MrSammi said:
time to buy an extra 'spare' CV shaft! :D


Congrats... Even I have a bit of FJ envy on ya! My sammi crawls at 114:1 or so right now (low enough for it)... it's fun to go slow! Just watch the gear changing and engine revving... LOT O TORQUE!!!
I already have a spare CV shaft, boots, grease, right and left seals, tools, yada yada... :) I know I will break one eventually (probably sooner than later). :)

I've actually thought about getting a manual shifter for the AT so I can control the shifting. I will just wheel it for a while and learn how it's going to react before changing anything.
 

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sbechtold said:
I already have a spare CV shaft, boots, grease, right and left seals, tools, yada yada... :) I know I will break one eventually (probably sooner than later). :)

I've actually thought about getting a manual shifter for the AT so I can control the shifting. I will just wheel it for a while and learn how it's going to react before changing anything.

I was saying an EXTRA spare... LOL!!

yeah... wheeling with the Taco guys that have crawlers... when the put in the clutch while there's pressure on the driveline... you hear the reverse backlash running through the gearboxes... the auto makes it even that much easier to put additional stress FWD to REV etc... you'll get a feel! I think it's great that you've got this done!! It's also really cool of Jim to do all that R&D so that you all now know you can swap out to the geared cases and get a 5:1 (4.7 might be stronger?) for a low range without the fuel tank issue...


Now you get to learn even more your level of pain... how tippy to get, how steep to climb... yehaw! lot's of new fun!
 

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Discussion Starter #8
MrSammi said:
I was saying an EXTRA spare... LOL!!

yeah... wheeling with the Taco guys that have crawlers... when the put in the clutch while there's pressure on the driveline... you hear the reverse backlash running through the gearboxes... the auto makes it even that much easier to put additional stress FWD to REV etc... you'll get a feel! I think it's great that you've got this done!! It's also really cool of Jim to do all that R&D so that you all now know you can swap out to the geared cases and get a 5:1 (4.7 might be stronger?) for a low range without the fuel tank issue...


Now you get to learn even more your level of pain... how tippy to get, how steep to climb... yehaw! lot's of new fun!
ha ha - I was apparently more dense then normal last night! LOL!

Part of our deal was to let him play with the truck for a while to make sure the geared tcase would fit w/o mods. It's actually great for all of us (FJC, 4Runner, Tacoma) that have the chain driven driver side drop cases. We can swap the stock tcase for the Inchworm driver side drop geared tcase and get better gears. IMO it's a great option and easy to do. I actually think Jim liked having the FJC in his shop to play with... it sounds like he's going to get one for himself eventually.

BTW, thanks for the information on how it will react and what to keep my eye open for. I appreciate it. I was hoping to make it to Moonrocks, but unfortunately I won't have the FJC back in time. Next run I'll go and see how much pucker factor I can stand.
 

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Discussion Starter #13
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.
 

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Discussion Starter #15
Do you think the stock case and a crawl box would fit if you cut 3 1/2" off the tank like you did originally?
Yes the stock tcase and a crawler would fit with the chopped tank.
 

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I just got in after driving the FJC back from Inchworm. Now with the lefty, crawler, and regeared axles. 247:1, baby, 247:1 ! :) :) :) Had some fun playing with it all over some bumps and hills with Jim near the Inchworm shop. Freekin' hillarious: An MT that I cannot stall with the foot on the break! Sorry for the giddiness - the first rig I've ever driven with even close to this crawl ratio. Unbe-freekin-lievable...
 

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Discussion Starter #17
Ahhh, the illustrious Inchworm testing bumps. I think everyone that has had a crawler installed by Jim drives over those dirt piles around the corner. Just wait until you get it on some rocks... that when the fun begins. Congrats on the install.
 

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That setup is the Shi*t , but I like the idea of Modding the
gas tank , Maybe if you're not doing the Inch worm setup, You could
INCREASE the gas tank capacity :) ,Well maybe on a Taco , the FJ has
less room under there from the looks of it.
 
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