33" w/ 4.56 Gears - Your Experience?

So I recently put 33" 255/85/16 Cooper ST Maxx on my Taco. I can tell there is at least a 300RPM difference in where it shifts now in order to compensate for the bigger tires. Less pep and it won't use 5th gear on the highway at 75 very easily.

So...I'm asking my local shop to quote me on a regear. Considering 4.56 gears and hoping to get input from those with 4.56 & 33's! I'm hoping to regear so the motor doesn't work as hard (saving wear and tear) and possibly helping me compensate for loss of fuel economy due to running higher RPMs now.

Most of my daily commute is 60-70mph and not much stop and go. I drive like grandpa because it's better for gas!

Planning for Moab this June so if I regear at all I want to do it soon.

Am I looking at the right gear ratio? And what is your feedback based on real experience? Thx!!

EDIT/Update: I ultimately ordered Front & Rear diffs from East Coast Gear & Supply (ECGS) with 4.56 Gears and ARB Air Lockers.

 

A gear ratio of 4.30 would put you back to stock perfectly. But nobody makes a 4.30 for our front diffs. So only option would be to go 4.56. And you'll be over geared. But that said, lots of folks have done it.

I have not regeared yet and have gotten used to it.

My wheel tire combo is 84 lbs. And 33.5" Toyo's.

When my truck gets some armor, it'll probably push me to regrear.

I'm gonna do the ECGS diff swap program with Nitro gears.

There's a really good thread around here for 33 inch tires and gears, if I can find it I will link it to this thread.

 

I've got armor on already so I guess I've got you there. LoL

I also want to do ARB air lockers too. Not sure if that impacts things.

I saw the Nitro Gear kit for like $1200 online to do front and rear.

 

That price probably included the RP gears and master install kits.

If you haven't already, check out East Coast gear supply.

Theyll warranty the gears for 5 years. You'll never ever see that from another vendor. Amazing!

http://eastcoastgearsupply.com

I got quotes from three local gear shops. Comparing all of my quotes I'll still be doing the differential swap from ECGS.

 

Google found me their site earlier. But I don't know enough about this to even price it out. No idea what pieces I actually need. At the same time I want to make sure my local shop gives me a fair quote.

The 1,235 included the master kits though. Found that here:
http://www.justdifferentials.com/GPTACO05PLUS-4-56-p/gptaco05plus-4.56.htm

Kit includes:
Nitro front ring & pinion
Nitro front Master Install Kit
Nitro rear ring & pinion
Nitro rear Master Install Kit
front pinion pre-load spacer
rear pinion pre-load spacer

 

I just swapped out front and back with ECGS and added a Detroit truetrac as well. ECGS will add the ARBs as well. I'm sure I could have taken my diffs to a local shop and saved a few bucks, but probably wouldn't have the confidence I do with having ECGS do it. It really is not that hard to swap the diffs out and just couldn't see paying someone to do that.

 

4:10s all the way. I run them with 35s due to how much highway/ freeway i drive and i wheel just fine. Ps I'm on really heavy tires as well. The red letters

 

So you found 4.10 gears for the front diff?

 

yeah ecg has em

 

I'm confused as hell. LoL

Obviously 4.88 makes no sense.

So it's either 4.56 to over gear or 4.10 to mimick stock setup. Reading another thread on 33's with 4.10 and its mostly bickering.

Would love some facts.

 

Just plug the numbers and see what each gear does to your RPMS and decide from there. I read all about how I was going too low and too high with the same gears. I decided where I wanted to be RPM wise at certain speeds and got what got me closest to it.
http://www.grimmjeeper.com/gears.html

 

Ok cool. So pretend I have no idea what numbers to plug in and don't know what the code number is for my transmission, etc....

 

What motor and transmission do you have?

 

4.0 & Auto (5speed)
4x4 obviously.

If I'm understanding other stuff I'm reading 4.10 puts me back to stock type ratios over all.

4.56 nets more torque but over gears me. That's great for offroad but bad for highway speeds.

 

I think that is an A750F, but hoping someone who knows will chime in. I have a different one so I can't say for sure. The http://www.grimmjeeper.com/gears.html calculator helps to see what RPMs you are currently running verses what you will be running at any speed in any gear.

 

Might play with that later then. Too complicated for this late at night.

Wondering if 4.10 is the way to go. Going to talk to my local shop.

 

OK. The calculator looks complicated but it's not. You basically put in your transmission, transfer case, tire size, and current gears on one side. On the other side you just change the gear ratio to whatever you want. You can compare your current RPMs to the new RPMs at any speed you want to plug in. Or you can compare different tire sizes to see how that changed things and more.

What I did was figure out what RPM my motor ran best at and what speed that currently was at. Then I decided what speed I would rather have that range at and changed gear ratios until one gave me that number. It's hard for someone else to tell you what is best for how you drive.

 

I am only a few mph off - 4.56 with 285/75/16 BFG MTs

 

Using the calculator, 4.10s and 33s will be slightly lower than your 3.73 gears were with the factory tires around 31.5 inches. Probably not even low enough to tell, but still slightly lower. Compared to 3.73 gears with 33s, the 4.10s will give you almost 200 more RPMs at 70MPH and 150 more RPMS at 55MPH. 4.56s will give you more than 300RPMS at 70MPH than the factory 31.5in tires and over 400 more RPMS at 70MPH with the 33in tires.

So really, you are deciding between 200 and 400 more RPMS at 70mph. See where that puts your motor at that speed and which one you prefer to be at.

4.10s are going to put things how it was with factory tires. That may be great if you liked how it drove then. If that was still too high geared, 4.56s will probably get you where you want to be.

 

This is what is confusing me. I'm at HIGHER RPMs now with 3.73 and 33s than I was with 3.73 and 30.5s. It's as if the motor has to push higher RPMs to achieve the same speeds. It seems to me regearing should allow the same speed at LOWER rpm since the motor doesn't work as hard.

But maybe that's only true at lower speeds. As it is now it wants to stay in 4th gear on the interstate to keep power.