Tell me about re-gearing my 5th gen

[dhatcher]

As I'm working on things to do to my 4runner (bumpers, lift, 285s), I'm starting to come across the subject of "re-gearing" a lot more. It came up recently during a class I took for learning more about off road driving. It was recommended that for a trail like the Rubicon that you have at least a 55 crawl ratio as calculated at 4lo.com

I was playing around with the calculator a little bit and starting to understand why people go from 3.73 to 4.56 or 4.88 or even 5.29.

My questions are probably somewhat basic, is this something people do to their daily driver rigs? Once you're into re-gearing are you pretty much relegating the use of your rig to off road driving or is it still suitable to slog through bay area commute traffic at 15 mph? Can I still go 65mph on the highway without relative pain? I'm sure gas mileage suffers just wondering if it's still bearable for daily driving use.

Also, how does re-gearing affect things like the factory locker, traction control, the speedometer and how do people work around or with these factors?

Thank you for any help, as always, greatly appreciated (i did search the 5th gen forums for re-gearing and found about 3 threads which I did skim through but, they seemed centered more about someone who already made up their mind to re-gear and just wondering what they should re-gear to).

 

[BigredTEX]

Re-gearing to 4.56 was one of the best things I have done to my rig. You can see in my signature everything else I've done.

This is my daily driver. I wouldn't go deeper than 4.56 if you intend to also drive it daily on the street. You will immediately notice more pep in city driving with a slight boost in MPG to boot. 65 mph on the highway is slow in my part of the world and you won't notice any degradation in highway performance at that speed, except that your cruise control will work much better without dropping one or two gears at the slightest hill and then overspeeding before settling back down. I cruise at 75 mph with no issues other than a slight drop in mpg, but it makes up for it by being much more responsive.

I say all this with 33 inch tires in mind. I plan to go to 34's later this year (285/75), which I probably won't notice a difference in city driving but will gain some legs on the highway. If you are planning to make your rig strictly a trail rig then 4.88 would be appropriate, but I don't see that working too well on the street.

In stock trim I feel the truck is geared too high and would work better with 3.90 of 4.10 gears. With 4.56 gears and 33 inch tires it feels more like it was intended if Toyota wasn't so occupied with mpg. In addition, the transmission shift points now seem to be much better integrated to the overall performance of the vehicle.

Bottom line, if you go to 33 inch tires, lift and some armor (bumper, skids, sliders, winch, etc.) 4.56 gears are appropriate and will give you better performance than stock.

 

[dhatcher]

Re-gearing to 4.56 was one of the best things I have done to my rig. You can see in my signature everything else I've done.

This is my daily driver. I wouldn't go deeper than 4.56 if you intend to also drive it daily on the street. You will immediately notice more pep in city driving with a slight boost in MPG to boot. 65 mph on the highway is slow in my part of the world and you won't notice any degradation in highway performance at that speed, except that your cruise control will work much better without dropping one or two gears at the slightest hill and then overspeeding before settling back down. I cruise at 75 mph with no issues other than a slight drop in mpg, but it makes up for it by being much more responsive.

I say all this with 33 inch tires in mind. I plan to go to 34's later this year (285/75), which I probably won't notice a difference in city driving but will gain some legs on the highway. If you are planning to make your rig strictly a trail rig then 4.88 would be appropriate, but I don't see that working too well on the street.

In stock trim I feel the truck is geared too high and would work better with 3.90 of 4.10 gears. With 4.56 gears and 33 inch tires it feels more like it was intended if Toyota wasn't so occupied with mpg. In addition, the transmission shift points now seem to be much better integrated to the overall performance of the vehicle.

Bottom line, if you go to 33 inch tires, lift and some armor (bumper, skids, sliders, winch, etc.) 4.56 gears are appropriate and will give you better performance than stock.

Thank you, that's exactly the kind of experience I was looking for. I had read a little in the other threads that 4.56 was questionable in some regards but, seems like you didn't have trouble with it? I'm planning for 285/70 (have 275/70 right now) and all the armor you mentioned (already have the rock sliders).

How did it affect your factory locker or traction control (if it did)? Were you able to keep it or did you have to throw it out and get air locker?

 

[wfo9]

Thank you, that's exactly the kind of experience I was looking for. I had read a little in the other threads that 4.56 was questionable in some regards but, seems like you didn't have trouble with it? I'm planning for 285/70 (have 275/70 right now) and all the armor you mentioned (already have the rock sliders).

How did it affect your factory locker or traction control (if it did)? Were you able to keep it or did you have to throw it out and get air locker?

Gearing will have no impact on any of the things you mentioned. Totally unrelated. Tire size will impact ATRAC.... but not gearing.

 

[BigredTEX]

Thank you, that's exactly the kind of experience I was looking for. I had read a little in the other threads that 4.56 was questionable in some regards but, seems like you didn't have trouble with it? I'm planning for 285/70 (have 275/70 right now) and all the armor you mentioned (already have the rock sliders).

How did it affect your factory locker or traction control (if it did)? Were you able to keep it or did you have to throw it out and get air locker?

What wfo9 said. No effect whatsoever on locker, speedo or ATRAC.

 

[lmturne1]

Silly question but i have to ask for clarity. When one regears their rig, are they regearing all 3 differentials (Front, transfercase, and rear), only the front and rear, or only the rear?

Where can the gears be found, who can perform the service, and how much is someone looking at for the whole process?


*Crawls back underneath rock*

 

[Engineer]

Silly question but i have to ask for clarity. When one regears their rig, are they regearing all 3 differentials (Front, transfercase, and rear), only the front and rear, or only the rear?

Where can the gears be found, who can perform the service, and how much is someone looking at for the whole process?


*Crawls back underneath rock*

Only the front and rear, the center differential (does not exist on SR5 and Trail/TRD models - only limited) is not something you change gears in like a ring and pinion gears in the diffs. while it is called a differential same as front and rear the similarities really end there. Google Torsen T3 if you want to know more.

Nitto makes the gears or Toyota( only offered in 4.56 and going to be $$$). East Coast Gear supply is a reputable shop where you can see pricing for just the parts or completed thirds and front clamshells to do the swap yourself.

A lot of folks go ahead and add an ARB front Air locker while they are at it which adds cost (~$800-1000) + compressor cost

IMHO if you have to ask 4.56 is likely the right choice and 4.88 you need to understand what you are getting if you go that route (not directed at you, just a general statement)

 

[wfo9]

Silly question but i have to ask for clarity. When one regears their rig, are they regearing all 3 differentials (Front, transfercase, and rear), only the front and rear, or only the rear?

Where can the gears be found, who can perform the service, and how much is someone looking at for the whole process?


*Crawls back underneath rock*

We are talking about ring and pinion in the front and rear differentials...

There is a low range reduction gear in the transfer case... but there is currently no option to run a higher reduction gear. I really wish there was...... I don't think there is enough room...

Cost is going to vary greatly based on who does the install. The ring and pinions are not that much 500-750... but it typically gets up pretty high 1500+ with labor.

 

[lmturne1]

We are talking about ring and pinion in the front and rear differentials...

There is a low range reduction gear in the transfer case... but there is currently no option to run a higher reduction gear. I really wish there was...... I don't think there is enough room...

Cost is going to vary greatly based on who does the install. The ring and pinions are not that much 500-750... but it typically gets up pretty high 1500+ with labor.

So regear with installation along with an airlocker, probably being from ARB, will yield a locked front end with a better power curve for daily driving with a fully loaded rig for roughly $2500.

Any hesitation to lock the front as the CV axles are exposed and would be prone to break? I would lock a straight axle if, for some reason, it wasn't already. Just a little skeptical on locking IFS...

 

[CharlestonFisher]

So regear with installation along with an airlocker, probably being from ARB, will yield a locked front end with a better power curve for daily driving with a fully loaded rig for roughly $2500.



Any hesitation to lock the front as the CV axles are exposed and would be prone to break? I would lock a straight axle if, for some reason, it wasn't already. Just a little skeptical on locking IFS...

I wouldn't add a locker to the front, quickest way to have a catastrophic failure on the trails. Too much for IFS.


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[ToyoT4R]

It would be interesting if Gear Vendors developed an under/overdrive setup for the 4Runner. Then you could go to a 4.88:1 with an overdrive or use an under drive for off-road only.

https://www.gearvendors.com/4x4.html

 

[willie2323]

It would be interesting if Gear Vendors developed an under/overdrive setup for the 4Runner. Then you could go to a 4.88:1 with an overdrive or use an under drive for off-road only.

https://www.gearvendors.com/4x4.html

Ah for the good ol days...back in 1970 I purchased my first 4WD (and still own it), a 1971 CJ5 Jeep. Before purchase I was pleasantly surprised when I took a look at the rear diff and saw the 4.89 posi tag. I knew immediately what I was going to do and did so within the week...purchased a 0.7 to 1 Warn overdrive that slapped right on the end of the offset transfer case (last year you could do this as in 72 the jeep line went to AMC but that's a story for another time...). These gears were perfect for off road and the overdrive made the V6 manageable on the highway. It is also a lot of fun to shift the fully syncro OD as you walk up thru the gears, still do it to this day!
cheers,
willie

 

[Jeremy556]

I wouldn't add a locker to the front, quickest way to have a catastrophic failure on the trails. Too much for IFS.

My stock CVs are close to 100K miles with a locker (190k total) and I spend a lot of time on difficult trails.

4.56 gears are my favorite mod.

 

[wfo9]

I wouldn't add a locker to the front, quickest way to have a catastrophic failure on the trails. Too much for IFS.


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Nope, not too much for IFS. I do way less damage to my rig on a given trail due to the front locker. I've watched others destroy their CVs with intense shock loads trying to momentum up an obstacle or with ATRAC jerking all over the place like a bucking bronco. I just crawl right up without any drama or parts flying...

Now... you can put more stress with a locker, since one wheel can take all the torque... and you can clearly bind things up. And if you don't know what you are doing...bad things can happen. It takes some skill and practice to know how and when to use it.. I just totally disagree that it is too much for IFS. I'm mostly silky smooth with mine now, but I have screwed up with it a few times and it held up fine.

 

[CharlestonFisher]

Nope, not too much for IFS. I do way less damage to my rig on a given trail due to the front locker. I've watched others destroy their CVs with intense shock loads trying to momentum up an obstacle or with ATRAC jerking all over the place like a bucking bronco. I just crawl right up without any drama or parts flying...

Now... you can put more stress with a locker, since one wheel can take all the torque... and you can clearly bind things up. And if you don't know what you are doing...bad things can happen. It takes some skill and practice to know how and when to use it.. I just totally disagree that it is too much for IFS. I'm mostly silky smooth with mine now, but I have screwed up with it a few times and it held up fine.

No doubt wild driving will lead to CV failures. Your description is spot on. I'm maintaining my opinion that locking the front is asking for trouble, but you make some good points.


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[Off2Mtns]

Go drive down the interstate in S4 to give yourself a real good idea what regeared topend will look like in D/5th. Your final drive ratio will still be geared lower than where you would actually be but sure put me at ease about turning too many RPM on the highway. S4 on stock size tires is turning 2700 rpm at 70mph. Regeared in 5th would be turning slightly less.

 

[Dimhof]

Any advice where to buy or who to do install on 4.56 in UT? A local shop quoted me around 1400 and also stated nobody made 4:56 for the late model 5th gens. I didn't bother to pry deeper because I swear several members on here have had theirs done

 

[wfo9]

No doubt wild driving will lead to CV failures. Your description is spot on. I'm maintaining my opinion that locking the front is asking for trouble, but you make some good points.


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The problem is.. when it comes to truly difficult high traction obstacles... You have two choices. Wild driving (with body damage and parts on the ground) or lockers. I choose lockers, but to each his own style.

If you are not doing really difficult stuff, well then no need for lockers at all. Most 5th gens don't need them as you can do quite a bit without them.

I maintain that it is not asking for trouble... Going out and wheeling your rig in difficult terrain... is asking for trouble. So stay home or just don't worry about it...

 

[BigredTEX]

Go drive down the interstate in S4 to give yourself a real good idea what regeared topend will look like in D/5th. Your final drive ratio will still be geared lower than where you would actually be but sure put me at ease about turning too many RPM on the highway. S4 on stock size tires is turning 2700 rpm at 70mph. Regeared in 5th would be turning slightly less.

That's not really true. According to this gear calculator http://http://www.grimmjeeper.com/gears.html you are 1,998 rpm at 70 mph with stock (3.73) gears and tire size while turning 2,361 rpm at 70 mph with 285/70 tires and 4.56 gears. You would be turning 2,775 rpm in 4th gear with stock setup.

You really don't lose too much running at highway speeds and pick up so much responsiveness and driveability.

 

[BigredTEX]

The problem is.. when it comes to truly difficult high traction obstacles... You have two choices. Wild driving (with body damage and parts on the ground) or lockers. I choose lockers, but to each his own style.

If you are not doing really difficult stuff, well then no need for lockers at all. Most 5th gens don't need them.

Lockers really do make a difference. My experience is driving style and tire size make much more difference when it comes to broken parts. My observations say once you go to 35" tires on these trucks things start breaking. In the past 30 days I've seen a broken CV axle and a broken rear ring and pinion on two different trucks with 35" tires. Both cases where not due to wild driving and both did not have front lockers, though the rears were locked in both. I have seen similar broken parts on trucks with 33" tires, but driving style was the main cause - blasting up rocky hills while wildly spinning the tires, some locked at both ends and some not.

If you need a front locker you are most likely in some very technical terrain and slowly picking your line through, not blasting through.