INSTALLED! 4.10 gears, ARB Locker, Detroit TrueTrac

Wasatch15 · **Joined:** Wed Jul 13, 2005 7:52 am **Posts:** 242

Could you tell me more about where you picked up the trutrac and 4.10 gears. I'd like prices too if you wouldn't mind.

Thanks
Ron

Skyjump136 · **Joined:** Tue Jul 05, 2005 6:50 pm **Posts:** 1633

www.drivetrainspecialists.com - TrueTrac $356.92
www.rustysoffroad.com - 8.25 4.10 gears $159 (I believe you have to call him to get that price)
www.newmoparparts.com - D30a 4.10 gears $359.20

Sport · **Posted:** Fri Oct 06, 2006 2:09 pm

If you installed those gears yourself, would you mind doing a write up and placing it in the tech section?

I want to try this in the near future and any references would be helpful. thanks.

Skyjump136 · **Joined:** Tue Jul 05, 2005 6:50 pm **Posts:** 1633

I've done some gear work, but for this I went straight to the pros. For all the $$$ I shelled out for parts I wanted it done perfectly. You can see my write up for the auburn limited slip diff in the tech section though...and you'll see why I didn't want to tackle this.

MILEAGE - I've gotten a couple PMs asking what change in mileage I've seen. After running one tank of gas through it I have seen a 2+ mpg increase with a mix of city and highway. I am used to seeing 16-17.5 mpg depending on conditions. With my last fill I calculated 19.52 mpg. It could get better though because I was doing a lot of hard accelerating since the 4.10s make me smile. :twisted:

Also, I would assume the transmission will need to re-calculate shift points over time and that sort of stuff. But yes, I've already seen a marked increase.

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

I definately recommend doing the 4.10 gears. Howerver, even a mechanic that has worked on transmissions and diffs for decades may redo the gears a couple times before they are completely happy with them. I don't know that a tech article would be very helpful. Part of it is experience. I take my Jeep to one person for this type of work. He did my gears, converter, and shift kit. He fixed the damage that the dealership did to it also.

Now that you've gone to 4.10's, you need a Fastman throttle body and a B&G flash. You will be pleasantly surprised. My Fastman throttle body made the most seat of the pants difference for the money out of all my modifications. The B&G flash is worth it for the torque management deletion alone.

If you've got the 42RLE, you should really start talking to people about a better torque converter. You're loosing a ton of power there. You will also need to try to find a shift kit so it will shift quicker, and it will increase the line pressure and help it lock up better and slip less.

If you're lucky enough to have the 45RFE, just call APS and get the torque converter and performance shift kit.

Everyone will swear you have a V8 in it.

Edit
Almost forgot, your computer won't completely figure it out with resetting it. You need to disconnect the POSITIVE cable from the battery. Turn the ignition to ON. Do not try to start it. After 15 seconds turn it back to OFF. Then reconnect the POSITIVE cable. Over the next 50 warm up cycles it will retrain the computers.

Edit
Make sure you have the NEGATIVE cable disconnected from the battery prior to doing anything with the electrical system. Reconnect the NEGATIVE as the last step.

Skyjump136 · **Joined:** Tue Jul 05, 2005 6:50 pm **Posts:** 1633

Good info...

One question though...a few years back I had the speedo recalibrated for the larger tires. Will performing the steps above delete that information from the computer as well? I'd rather hang on to that...

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

Resetting or reprogramming your PCM isn't going to delete info like that. It just resets the adaptive sections. No worries.

Skyjump136 · **Joined:** Tue Jul 05, 2005 6:50 pm **Posts:** 1633

Thanks...I'm all reset now. I guess.

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

After reseting the PCM, it will usually take it from a few seconds to a minute to idle smoothly. It may bog down a little if you stomp on it at first since it will be running really rich at first. During the next couple days of learning, it will lean out the afr and you should feel it start performing a lot better.

Skyjump136 · **Joined:** Tue Jul 05, 2005 6:50 pm **Posts:** 1633

Yeah, it stalled first time I fired it up this morning, but now things seem to be running smooth again.

OzLtd · **Posted:** Sun Oct 08, 2006 9:30 pm

KJ Liberty, I assume you're referring to the petrol KJ's ? What about the CRD's, will they have the same perameters ?

Regards
Stu

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

Once it drives well under normal situations, drive it aggressively some also. You want to make sure it knows exactly what to do under full throttle too. If you tow, make sure you tow something during it's learning phase. Then drive the way you normally do for the rest of the learning phase and it should set itself up according to your driving habits and the configuration of your Jeep. This method has always worked well for me.

I've never dealt with the CRD, but I know that the Dodge and Jeep gas motors computers are like this. I would really think the CRD would be the same.

INSTALLED! 4.10 gears, ARB Locker, Detroit TrueTrac

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