Another 2011 w/ 4.56s!!!

Picked my truck up from the shop today after having Nitro 4.56s installed. I have a 500-mile break-in per the manufacturer, so I haven't been able to really test them out yet; however, the shop is 65 miles away from where I live and on the drive back, my truck averaged 18.6 MPG @ 50 MPH. I drive the same route several times a month and there are several large hills that my truck ALWAYS downshifts two gears on, but today my truck didn't downshift out of overdrive one time!! I also noticed the MDS stayed on the majority of the trip home, which it never did before.

For those of you that don't know, I started with 3.55s. I'm sorry if I offend those of you that like the 3.55s, but IMO, those gears are good for nothing!! I can't believe 3.55s are even an option with the stock 20s and 33" tires. The 3.55s are bad enough with stock 265/70R17s!! Anyways, I'm so glad to be rid of those terrible gears.

The shop said the gear install went very smooth. I used master install kits on both front and rear, as well as, new inner axles seals. After the 500-mile break-in period, the shop is going to change the gear oil in both ends and make sure that everything is OK. After that I'm going to give it HELL!!

Now that my gear install is complete, I now have an open differential for sale for $150 + shipping for anyone wanting to go the same route I did.

Nice and congrats! I'm about to pull the trigger on 4.56s myself just as soon as the tax return goes into my back account.

Congrats! Mind if I ask what this set you back - just to see if its in the cards for me?

Nitro Gears? Never heard of em. They have 4.56s for the ZF rear end?!

I need some!

Ok, so I have a question, if I go from 3.92 to 4.56 would that help or hurt my MPG? I take this hill coming home from work everyday and my truck always downshifts on it and bugs the hell out of me....should this be something I should be considering? I would not want to hurt my MPG but don't know a lot about gears in general.

HEY HEY!! Glad to see the install went well. You going to do the 500 break-in rule?? Thought it was just for towing.........better safe than sorry I guess. The power is nice for sure, I cant imagine it with 35s. I bet you can light em up at will! Enjoy em and keep us posted afteer the break-in period.

Nitro Gears? Never heard of em. They have 4.56s for the ZF rear end?!

I need some!

No Nitro doesnt make any for the ZF axles. He had his carrier modded and used gears for the pre '11 non ZF rearends

Awesome bro!

You guys most have some crazy hills!! Drove across thae states from top to bottom and not one time my truck downshifted on it's own? Would the 3.73s make that much diff?

Originally Posted by Musclemckeester

Nice and congrats! I'm about to pull the trigger on 4.56s myself just as soon as the tax return goes into my back account.

Thanks man! Now it's your turn!

Originally Posted by tadamson

Congrats! Mind if I ask what this set you back - just to see if its in the cards for me?

Gears, master install kits, used open diff., machine work to diff., inner axle seals, gear oil, lots of shipping expenses, and labor = $2400

Originally Posted by JJP71584

Ok, so I have a question, if I go from 3.92 to 4.56 would that help or hurt my MPG? I take this hill coming home from work everyday and my truck always downshifts on it and bugs the hell out of me....should this be something I should be considering? I would not want to hurt my MPG but don't know a lot about gears in general.

If you're sticking with stock size tires or something close, IMO the 3.92s are good enough. If you plan on running 35s or bigger in the future, then I would definitely do 4.56s.

Originally Posted by candy08

HEY HEY!! Glad to see the install went well. You going to do the 500 break-in rule?? Thought it was just for towing.........better safe than sorry I guess. The power is nice for sure, I cant imagine it with 35s. I bet you can light em up at will! Enjoy em and keep us posted afteer the break-in period.

Yeah, I think I'm going to do the whole 500 mile break-in. The manufacturer and my installer highly recommends it whether towing or not.

let us know about hwy. mpg when you can. tks

Originally Posted by huntergreen

let us know about hwy. mpg when you can. tks

Will do!

My break-in period and post break-in inspection/gear oil change will be done on Friday and then I really get to try them out. A few WOT pulls should do the trick!

Whats the name of the shop you had it done at?

the hemi and 4.7 must be way diffrent when i set the cruze at 50 i get 24.5 with my chip on 91 tune with 87 gas and i have 3.55 but want to go steeper

Originally Posted by BGRTHNURHEMI

Whats the name of the shop you had it done at?

Baertrax in Dallas. I highly recommend this shop. Josh (the owner) is really a stand up guy.

Originally Posted by HollaifyaHEMI!!

Thanks man! Now it's your turn!

Gears, master install kits, used open diff., machine work to diff., inner axle seals, gear oil, lots of shipping expenses, and labor = $2400

Agreed! That's not a bad price at all. To use the stock LSD it's going to run me $1800 that's just for gears, other parts, and labor.

Originally Posted by Musclemckeester

Agreed! That's not a bad price at all. To use the stock LSD it's going to run me $1800 that's just for gears, other parts, and labor.

That's the only thing holding me back as well. Apparently it's a lot harder to machine the stock LSD than the open carrier. But I can't be without my truck, so its looking like a new LSD, i.e. candy. Just gotta save the $!

Originally Posted by kauffman_c

That's the only thing holding me back as well. Apparently it's a lot harder to machine the stock LSD than the open carrier. But I can't be without my truck, so its looking like a new LSD, i.e. candy. Just gotta save the $!

Have you talked to any shops around here about it yet?

Originally Posted by Musclemckeester

Have you talked to any shops around here about it yet?

I have talked to 2 diff shops around town, and neither have been helpful. One said he would get with a machine shop and get me some pricing, but nobody has bothered to follow up with me. I have pricing for the gear swap, but the machining is the kicker that I'm waiting for answers on.

You could probably talk to the shop that candy and hollaifyahemi used, but that's a lot of shipping charges (VA i think), and a lot of down time for the truck (unless you buy the new LSD).

Originally Posted by kauffman_c

I have talked to 2 diff shops around town, and neither have been helpful. One said he would get with a machine shop and get me some pricing, but nobody has bothered to follow up with me. I have pricing for the gear swap, but the machining is the kicker that I'm waiting for answers on.

You could probably talk to the shop that candy and hollaifyahemi used, but that's a lot of shipping charges (VA i think), and a lot of down time for the truck (unless you buy the new LSD).

Mine is a 2010...I don't need anything modified thankfully. I was just asking out of curiosity. Did you talk to Northwest (290) Drive Train?

Originally Posted by Musclemckeester

Mine is a 2010...I don't need anything modified thankfully. I was just asking out of curiosity. Did you talk to Northwest (290) Drive Train?

First place I called. Luckily they are just down the street from my shop, so I'm going to see them at lunch today.