Can someone explain to me how this all works? I have been doing some research on Detroit Truetrac, and Detroit lockers for my 2003 DII. And am curious how the installing the 4:11 gears work. So do you buy the Truetrac diff and have the 4:11 spline gears installed on it? Is that where the gear reduction takes place or is there work done to the transfer case? Looks like for about $950 and some gear oil you could have a set of Truetracs and upgraded HD axles are not required immediately if you are not rock crawling and hard on things.

Also would these 4:11 gears be necessary for running 265/75/16 Duratracs tires. Would I gain that much mpg back or would it not matter until I went to a 285 tire. Just curious. I love these Duratracs and have not seen my MPG's go down much from switching from a 245/75/16

My research so far has been of off Great Basin Rovers site.
gbrutah.com/cs_drivetrain diff carriers.html

Someone take me to school on this.

Dave

 

I would suggest you send me your number so I can call you, cause you are so completely lost with this one.

 

Amazon.com: How To Win Friends and Influence People (9781439167342): Dale Carnegie: Books

 

Go ahead and call Mike but the Tru Trac is where the new ring and pinion will attach to and it is done in the diff on the axle, you do not need to touch teh tranfer case. One cool thing about our trucks is that the carrier drops out and can be worked on. Plus you do not want one in the front axle. It would cost more but maybe look at the ARB instead and if cost is an issue just get one in the rear.

 

Thanks hansome rob,
That is what I was thinking, but did not know. I dont have the cash for this right now but was curious. After reading on GBR's site. Its sounds like at Detroit locker in the rear and a Truetrac in the front would be a good combination.

Does anyone know if the 4:11 gears are necessary for 265/75/16 tire diameter? Will it improve your MPG enough over time to get have a little return on investment?

 

Yeah you can run it the front, but for me it depends on what you use the vehicle for the most. You cannot beat the ARB for open diff and then locking it up allt he way, the Tru Trac will not be as efficient.

The return on the investment is not really going to happen. You can use it to justify your purchase if you want but do not place too much faith in it since it will take years to pay off. You can probably count on 3.5+ MPG drop over stock for that tire size, but I do not know what your current tire already dropped.

You will get some of your torque back though with the gears so that is always good. Good luck and keep asking questions.

 

why don't you put the CDL guts in your transfer case and get that working first? Then if you think you need more put a detroit in the rear. the traction control and a CDL are pretty amazing combo.

 

The CDL is being installed by me tonight tomorrow and Wednesday how ever long it takes! I run 265/75/16's and use Gas Book to track my fuel and MPG for the last two years on the iPhone. Looks like I am still averging 13.5mpg with the Duratracks and Volo chip, b/t highway and city. I dont have the money for this expensive gearing project but was just curious as to how it all works. I've talk with the guy at Great Basin Rovers and he is a great help. It looks like the price breakdown would be about like this:

4:11 ring gears $250 needed for both front and rear. GBR
Detroit Locker rear $585 eBay
+ HD rear axles for rear. $?

The front I would leave alone till I felt I needed more.
Just going up a step rutted and soft dried soft clay or mudded logging road this weekend was awesome with the Duratracs and traction control. They would slip a little then the T/C would figure it out and keep going. If I had a CDL it might have been 50% better. I like the slipping and taking it easy. If you have full traction all the time, where is the fun in that. Gotta let the Rover figure it out. + I have a winch I have not used yet

THis is the best video I have seen on youtube to date explaining a CDL.

http://www.youtube.com/watch?v=6H0AM...eature=related

 

you putting a d1 setup in? the hardest part is taking the console apart for the first time. i have done it literally 20-30 times. i can do it in like 15 minutes now. use sheet metal screws instead of rivets when putting it back together.

i think you will be very happy with the cdl and TC.

I don't have a desire to put lockers in my d2, would rather import a defender and make something that will really melt my heart (and my wallet)

 

Yes a D1 shifter with a D1 hi/lo selector and a 2004 Output. Then I will sell the whole T/c with my 03 output and get my $350 back.

I think the rear locking diff might be nice. Depends if I move to Colorado in the Spring and get in some crazy trails. I am new to all this stuff so I just need some good time and teaching on some intermediate trails.

I know about the sheet metal screws. I take my time go slow and dont break stuff so with the Josh's instructions I think it should go OK. Plus I just dropped my Y pipe for an exhaust gasket replacement and refitted with antisieze...so I know those studs should not give me hell. I'm going to cut the two rear bolts and replace them with stainless bolts. removal should go faster that way.