Best box to use to get Twin t-cases behind 3RZ-FE??

[awsumdc]

Ive been told the opposite, no disrespect guys, but Ive been told thats its better to put the front crawler case (4.7's) in LOW and the rear factory case in 4HIGH and then just shift through the auto through the gears for whatever speed you need/require....

I was doing this on the weekend in the hilux and it works fantastically for me.

I'd only need to put the factory (REAR) case into low range with the front Crawler case in low range aswell if I was going to be crawling rocks with it, but fo the majorty of the rutted and hilly tracks we do the former works best.

Max you are right.

The thought some time ago that the input shaft on these newer gear driven case's are just as weak as the input shaft on the gear driven case's has been around for awhile and nothing could be further from the truth.

These newer chain case's were designed and built for both a heavier vehicle and a vehicle with a stronger motor. And for those that say the chains are weak on these newer case's I'd love to see the pile of chain case's that have blown either a planetary gear or the chain. I myself have never seen a chain case break except for when some landed on a rock and cracked the housing, but I can show you a pile of gear case's including a couple of Atlas's that have taking a dump.

I've been running around with my front case in low and my rear case in Hi now for over three years without one problem to either the front or the rear case and I have a 6,000lb truck with Dana 60's front and rear and sitting on 40" tires. And I'm not the only one who rides around all day with their front case in low and rear case in hi. We all pretty much do it here in the states without failure.

The thought of not putting the front case in low while the rear case is in hi just doesn't even make sense. The strongest gear your going to have is the hi gear since it's smaller and the amount of torque that is applied to the rear case from the front case is going to be the same whether the rear case is in hi or low.

So max your going to be fine. Run around with your front case in low and your rear in hi. That chain case you have is one of the strongest case's Toyota has ever made and your crawler box is the strongest Toyota crawler on the planet. Your going to fine Dude. Wheel responsibly and just remember your out there to have fun. Your not in competition.

Here is my 6,000lb truck with the stock chain case and 4.70 gears in the front case crawling along with both case's in low.

There seams to be a lot of confusion in this thread. Most are talking stock 21 spline gear driven transfers not Chain drive transfers. Your currently talking the 23 spline chain drive case. HUGE difference in strength.

Yes your right. The 23 splined chain case's are a HUGE difference in strength from the 21 spline gear case's. Thats why we can run around with crawler gears in front of our transfer case's instead of putting the crawler gears in the rear case. A gear driven case from a Toyota wouldn't stand a chance in my truck, not even Marlin's upgraded lefty case. Thats why we leave the stock case in and put the crawler gears in front of the transfer case. Not worried about the input or out put shafts on these chain case's.

[awsumdc]

I can't say that you guys are correct. I'm with Ruff. You are putting crawler gears in the front box which is putting roughly 4 times the torque load on the second transfer input shaft than what it was built for.

With a standard transfer up front and crawler gears in the rear you are only putting twice the torque on the second transfer input shaft.

So I know what I would be doing. But I think running stock twins with cromo output is heaps with the 3RZ motor.

Remember the transfer input comes straight from the gearbox and this is what is was built for. Not having reduction in front of it as well.

Torque works down the drive train. So up front is effecting down to the rear.

You can believe what you may from Mathematical theories, I'm just letting you know what we have done here for years with these chain case's and crawler gears in front of them.

Infact, what we'er seeing now is that the Crawler Box is blowing before anything happens to the chain driven transfer case. They made all the internals stronger and now the case's on the crawler box's are giving ay on some of these trucks where the guys are really getting on them in the rocks out here. The theory of Down line torque multiplication is having a hard time explaining that one.

Not to mention the fact that Marlin himself along with his son big mike are running TRIPLE case's in their trucks without any issues to the very rear case and their rear case IS a gear driven case.


My final crawl ratio is 227:1 with my dual setup. Marlins is a staggering 1,372:1 with his triple case setup. Can you imagine the down line torque multiplication he's got going on in that truck. But he's not having any issues at all.

We thought outside of the box and allowed ourselves further possibilities. We just want to provide you great folks with the same possibilities.

If built right and put into the right vehicle, you can put low crawler gears in front of a gear or chain case. It's been done over and over again without the drama that some people believe will happen.

[Willy Hilux]

So how do you guys go about top shifting the chain drive transfer??

[mmaaxx]

So how do you guys go about top shifting the chain drive transfer??

we had to convert it in my hilux from a forward shift to a top shift. In the US, the FJ's and Taco's have the chain drive transfercases but they are top shift, for some reason Toyota thought the Aussie market would be better with a forward shift.

Heres a pic of my transfer with the forward shift shafts extended out the front-


We purchased an 03 V6 Hilux transfercase with right hand drop and took the shift rods out of it because the 03 uses a top shift chain drive case. We then rebuilt my 07 hilux forward shift case into a top shift case and put a cover on the opening in the transmission adaptor plate that the shifter and longer rods were in previously.

Heres a pic of the case after the conversion, you can see the shorter shafts have been fitted and a Marlin quick shift aswell-


So thats how we went about "top shifting" the chain drive transfercase.....but note, previous generation Hilux's had the top shift aswell....I beleive the single cabs with the bench seats had a forward shift because of the cab configurations but you need to double check the setup before diving in.

[awsumdc]

So how do you guys go about top shifting the chain drive transfer??

Again Max is right.

You see, here in the states the Tacoma's, FJ Cruisers, 4Runners, and Tundra's are all either top shift or electronic shift transfer case's.

Here is the completely electroninc shifting case in my 2005 Tacoma before installing the Marlin Crawler to it.
Notice that the top is covered by a plate and the front of it there are no rods coming out of it. It is shifted by a single rod from the rear by a motor much like the rear lockers are activated.



Here is the dual case setup of the same transfer case with a Marlin Crawler mated to it.


Here is an earlier model Tacoma that is top shift transfer case with a Marlin Crawler mated to it.


Here are the shifters for it.


An FJ Cruiser we did.


Then there is Max's Hilux we just did last month. We had to modify his transfer case and turn it from a forward shift case to a top shift case.