Inchworm Gear Crawler with Triple Sticks (1 Viewer)

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Joined
Jan 26, 2006
Threads
13
Messages
396
Location
CA
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 while back with Jim at Inchworm to have it slowed down a little... :) I wanted to have a crawler box installed and Jim needed a donor vehicle to do some testing/prototyping with his new gear driven transfer case and V6 adapters. Jim installed his new driver side drop geared transfer case (a.k.a. Lefty) along with a crawler box. The front reduction box has 2.28:1 gears and the transfer case has a 5:1 gear set. 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 transfer case lever position, so no floor board 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. Some shifter modifications are required. The geared transfer case is a great solution for folks that want to run lower gears (3.0:1,4.0:1, 4.7:1, 5.0:1, 5.7:1), but don't want/need a crawler. If you want a crawler box you can install Inchworm's crawler with their gear driven transfer case or your stock FJC transfer case.

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. Click on a thumbnail to enlarge the image.

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. My FJC has a nice flat belly now. I will be removing the factory cross member in the future and adding a flat belly pan.



The gas tank in the FJC's is very close to the stock transfer case 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. You only need to modify the gas tank if you plan to install a crawler. You don't need to modify the gas tank to install just the geared transfer case with lower gears.



Then there is the triple sticks, which I think are just cool. The left stick controls the H/L range gears in the reduction (crawler) box. The center stick controls the gears in the transfer case and the right stick controls 2WD and 4WD. Nice thing about the triple sticks is I now have the low gears in 2WD as well as about 15 different gear selections with the transmission gears.



If you are interested in getting a crawler or lower gears for your FJ Cruiser, Inchworm has them available. Here is the contact information for Inchworm Rock Walkin' Gear.

www.inchwormgear.com 1-530-677-8111

This has absolutely been the best modification that I've done to date. The control that a crawler gives you when wheeling is amazing. The lower gears are much improved over the stock transfer case gears.
 
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There's only one word for that mod - Cool !

When you get it off road get some pics etc. Maybe you could YouTube a video or whatever.

:beer:
 
You worried about your front CV's??? That's a lot of torque multiplication.

Will this work with the 6sp as well?
 
Just checked out the website. Will work with the manual tranny but obviously you will no longer be full-time 4wd.
 
thats pretty sick. i like the direction fj cruisers are heading
 
You worried about your front CV's??? That's a lot of torque multiplication.

Will this work with the 6sp as well?

Yes I am worried about breaking a front CV's, but I was worried about them prior to installing the crawler. I always carry a spare CV when wheeling. Yes it will work with the 6spd MT.
 
Just checked out the website. Will work with the manual tranny but obviously you will no longer be full-time 4wd.

There are two options:

Install Lefty the geared transfer case and a crawler box and yes you will lose all-wheel-drive.

Install only the crawler box with your existing transfer case and no you will not lose all-wheel-drive.
 
So if you add the crawler box to the stock t-case, you gain 8-8.5" in drivetrain length. At that point you would need to do the gas tank mod and floorboard mod, or can you fab up some linkage to keep the stock t-case shifter in the stock location? Sorry for the questions, I'm not familiar with the underside of the FJC.
 
Yes you are correct in terms of the drive train length and gas tanks mods. However, the floor board mods are not required if you go with the triple stick setup that I installed. With the triple sticks, all of the shifters come up through the stock hole in the floor. The triple sticks are connected to each of the shift rails in the transfer case and the reduction (crawler) box via a linkage system.
 
I'm looking ahead for t/c gearing options. Is Inchworm the only one so far in this market - offering a t/c replacement? Am I right in reading their website saying that no gearing options can be made for the stock FJC t/c? I'm not looking to go bigger than 33s, but would definitely like to improve my crawl ratio (maybe the 4.0 or 4.7 range).
 
I'm looking ahead for t/c gearing options. Is Inchworm the only one so far in this market - offering a t/c replacement? Am I right in reading their website saying that no gearing options can be made for the stock FJC t/c? I'm not looking to go bigger than 33s, but would definitely like to improve my crawl ratio (maybe the 4.0 or 4.7 range).

The existing tcase in your FJC (4Runner's and Tacoma's) uses a planetary gear and is chain driven. No one has made replacement gears for the planetary setup. The main reasons are that there is not enough room in the case and two the cost would be outrageous. So yes you are correct that you cannot re-gear your existing tcase.

You should call and talk to Jim about the Lefty transfer case. Lefty is a tcase swap for your existing tcase. Lefty is a gear driven tcase so you can have any gear ratio (3:1, 4:1, 4.7:1, 5:1, 5.7:1) installed that you want.
 
Hmmm,,, so if a person installs only the Lefty t/c, do you still gain the clearance to push up the exhaust and have the flat belly? Suppose I should call Inchworm and ask them. This could prove to be the best mod going in the market today. Although, I bet it would negate all of the factory driveline warranty..?
 
Lefty was designed with clocking built-into the transfer case, so you will get a flat belly with just the tcase swap. As for the best mod going, I have to agree. The control that you gain from a crawler is priceless.
 
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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