Gear change question

[WU7X]

I have a 2011 T4R with 3" OME med. duty springs front and rear paired with OME shocks. My tires are Cooper ST/Maxx's which I have run for almost two years now. I tow a small RTT/trailer that loaded weighs under 1,500 lbs.

I am thinking of replacing the stock 3.73 gears with a set of Nitro 4.56's. The reasoning is that with the larger than stock tires, if feels like the vehicle just doesn't have the power it originally did. Also the Nitro rep I spoke with said that the 5th gens are geared pretty high from the factory.

Does anyone have experience with a conversion like this? Has it changed power? Gas mileage? I will not be including locker btw.

 

[Ol'Baditude]

I have a 2011 T4R with 3" OME med. duty springs front and rear paired with OME shocks. My tires are Cooper ST/Maxx's which I have run for almost two years now. I tow a small RTT/trailer that loaded weighs under 1,500 lbs.

I am thinking of replacing the stock 3.73 gears with a set of Nitro 4.56's. The reasoning is that with the larger than stock tires, if feels like the vehicle just doesn't have the power it originally did. Also the Nitro rep I spoke with said that the 5th gens are geared pretty high from the factory.

Does anyone have experience with a conversion like this? Has it changed power? Gas mileage? I will not be including locker btw.

Lots of people on this forum have made the jump from stock to 4.56 gears.
From their reports you'll notice the following:
1. The vehicle will rev a bit higher: say 2200rpm at 65mph rather than 1900rpm at stock. ymmv
2. In terms of acceleration, the vehicle will feel more like it did before you put the bigger tires and all the armor and gear on there.
3. The vehicle will shift differently(some say it fixes the shift points) i.e. the vehicle does not automatically downshift at the mere sight of an incline in the highway.
4. The vehicle will perform noticeably better offroad, particularly when you're crawling or climbing steep inclines.

As far as mileage goes, I would guess that there's not going to be a huge difference and that the higher revs would be somewhat canceled out by the fact that the vehicle isn't laboring nearly as much during your trip. And yes, the gears and the transmissions on our 5th gens are definitely focused more towards mileage than offroad capability.


I haven't done the gear swap in mine yet(parts are on order), however, I have driven a heavily modified FJ on 35's that had 4:88's. A bit much imo, but I could not believe the getup and go in that thing! It was like I was driving a Camry. That said, top speed was limited to ~60mph.

 

[delloro]

OP if you normally turn 2000 rpm at 70 mph, then you will turn (2000x4.56)/3.73=2445 rpm at 70.

Your mileage will suffer, there is a reason modern cars have tall gearing. For the mpg.

Whether or not the mpg hit is worth it, whatever it is, will be up to you.

 

[mikey's2010SR5]

I have yet to do my gears but it's in the batters box now.

For me I want to change gears because my truck (rolling 34s and a ton of weight) just can't seem to find a gear it likes, especially up hill. I am not worried about gas mileage since it's not my daily but I look forward to having the advantage of slower crawling on trails.

I eventually want to get a teardrop down the road so the gears will definitely be needed by then. Shooting for summer then give you a versus comparison.


Sent from my iPhone using Tapatalk

 

[LawnDart]

I'll say this, if you have any intention of towing, get 4.88s. Everyone I've ever talked with who went 4.56s always wishes they'd gone a step up to 4.88s.

My truck feels about as peppy on 35s as it did on 31s.

 

[fourwd1]

I have a 2011 T4R with 3" OME med. duty springs front and rear paired with OME shocks. My tires are Cooper ST/Maxx's which I have run for almost two years now. I tow a small RTT/trailer that loaded weighs under 1,500 lbs.

I am thinking of replacing the stock 3.73 gears with a set of Nitro 4.56's. The reasoning is that with the larger than stock tires, if feels like the vehicle just doesn't have the power it originally did. Also the Nitro rep I spoke with said that the 5th gens are geared pretty high from the factory.

Does anyone have experience with a conversion like this? Has it changed power? Gas mileage? I will not be including locker btw.

You've left out a crucial factor, what size tires do you have now and what size are you going to?
3.73 is a pretty high ratio, and 4.56 is a big jump.
Another important factor is what trans, manual or auto?
That is a big factor in gear selection.

 

[fourwd1]

And the next thing your not including a locker.
If you ever thought about it now is the time to do it.
The cost savings in labor hours to do it all at once is huge .

 

[WU7X]

Boy, great replies everyone! Thank you.

Right now I am running Cooper Discoverer ST/Maxx tires 255/80R17. This is about a 31.5" tire.

I tow a lightweight Freespirit Recreation Basecamp XL RTT/trailer. It is one of their original versions with 28" BFG's. I love it but like their newer version better. I've got about 15,000 miles on it, including several trips to the midwest and back and a couple trips to SE Utah.

In the future I'll probably be going to a teardrop, primarily because we are looking at a trip up to Alaska and my wife wants a hard shell surrounding us at night. The one I am interested in right now is the Inka Venture OHV. So my towing weight will also be going up.

The vehicle sees a lot of dirt and gravel roads, including some two track. I don't do rock crawling.

Does this info help with the gear swap questions I posted?

 

[rochmpr]

With larger tires and armor, it's a huge improvement. Even with larger tires, overall gearing will be lower than stock, with the exception of 35" - 36" tires. I am currently 7.07% lower than stock with 4.56 gears and 34" tires and average about 15 mpg.

 

[weeeee]

I'll say this, if you have any intention of towing, get 4.88s. Everyone I've ever talked with who went 4.56s always wishes they'd gone a step up to 4.88s.

My truck feels about as peppy on 35s as it did on 31s.

OP is running 32". I would not go above 4.56 in his application.

 

[BigredTEX]

I just pulled the trigger on 4.56 gears today and will be installing within the next 30 days. If you have questions about tire size and RPM, check out this web site:

Gear Ratio Calculator

You can play "what if" all day long on this site. I'm currently running 285/70's and will be going to 285/75's this summer. I know how the truck struggles on 33" tires and it will only get worse with 34" tires.

Looking forward to the change.

 

[jrob]

You've left out a crucial factor, what size tires do you have now and what size are you going to?
3.73 is a pretty high ratio, and 4.56 is a big jump.
Another important factor is what trans, manual or auto?
That is a big factor in gear selection.

Considering this a 5th gen, there isn't an option between stock 3.73 and 4.56.
Edit: Auto trans only.

Boy, great replies everyone! Thank you.

Right now I am running Cooper Discoverer ST/Maxx tires 255/80R17. This is about a 31.5" tire.

Actually that's a 33" tire. 32.8" according to Cooper but a member here pulled actual measurements at just a touch over 33". [MENTION=64685]TOY2G[/MENTION] I think.
I can verify they are a fair amount taller than my 285/70 17 Duratracs, granted they are heavily worn.


Here is another good thread with some more input from other guys that have done it:

http://www.toyota-4runner.org/5th-gen-t4rs/187545-5th-gen-gear-swaps.html

Gears were on the short list when I lived in Colorado, but living in Texas they have been back burnered. I did just get a wake boat though, so they climbed back up the list a bit.
Going 4.56 when the time comes through ecgs as is a popular option.
Toyota 8.2 Elocker 3rd member- FJ Cruiser / 4runner

Good luck!

 

[CF_Machete]

before you regear, which could get costly, why not install a TRD CAI http://www.toyota-4runner.org/5th-gen-t4rs/85960-how-guide-trd-cai-installation.html

Buying the part separately cost around $200 and with a K&N air filter, my truck feels more peppy with 285/70/17s that with the stockers. Install shou take about an hour.

 

[wfo9]

456 is what you want. 488 would not be good at all unless you went to at least 35s and even then the motor is spinning a little too high to even be close to the efficiency range hwy wise. 488 would be perfect or 36-37" tires.

Expect a drop in mpg and improvement in tq and shifting with better gearing. If you currently hunt for gears constantly, you may see a slight improvement in mpg. I cold still squeeze 18mpg on trips with 34" MTs and 456s for a while. I doubt I could still do that with an aftermarket bumper. The aerodynamics take a big hit....

As far as a locker goes. Really worth doing at the same time. ARBs add strength also, It is an entire billet carrier with stronger side and spider gears. It basically will not fail and shifts the weak point to the ring, pinion, and housing itself (those already may be the weak link, but the arb carrier is basically indestructible unless metal chunks from other bind it up). Also, the arb front carrier is fully machined vs cast it also uses an oil impregnated bushing vs the needle bearings that tend to wear out and cause slop and noise (very common problem with the 5th gen front diff). Just some things to consider. But if you don't need a locker ever, just skip it. They are not cheap at all, so it would be a waste of money if you never used it.

 

[WU7X]

Hey guys. Thanks so much for the information. it is great to hear from you folks with experience and know-how. I'll let you know what happens with this. Still willing to hear more from those who know.

Dale