Tell me about re-gearing my 5th gen

[BigredTEX]

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

Nitro makes 4.56 gears for the 5th Gen and 4.88's too. East Coast Gear does a core swap that's relatively reasonable. I had mine regeard for $1,700, all in. That's relatively cheap and it kind of depends on who you know. East Cost has core swap pricing on their web site, but you still need to R&R the rear 3rd member and front pumpkin. That will save on installation cost.

I paid $1,000 for the gears and master install kits and $700 for installation, but I got very good deals on both, saving at least $600 overall. My son is having his 4th Gen done as we speak (he blew his stock rear ring and pinion last weekend) for approx. $900 all in, but again, it is who he knows. If you pay retail for the gears and install it could exceed $2,000 very easily. Even at that price I feel it is worth it.

 

[wfo9]

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.

Agree, 4th gear on hwy stock gearing is equivalent to 5.18 gearing in 5th gear. 4.56 is quite a bit different. It is a 400rpm difference from stock in 5th gear.

 

[wfo9]

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.

Don't forget. These truck are not all the same. Many people package FJs and 4th gens into the same group. They are similar, but when it comes to the rear diff... big difference. The 4th gens and older FJs will break the rear diff pretty easy. The newer rear diff seems to be much stronger. I've seen many broken Toyotas.. Still have not seen a 5th gen rear diff fail.

 

[CharlestonFisher]

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.

I see two different choices, picking the right line and employing skilled two pedal driving, or taking the bypass. I won't break my rig either way. There have been very few instances in my wheeling experience where I think a front locker would have really helped.

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

True statement. Cheers! [emoji482]




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[BigredTEX]

Don't forget. These truck are not all the same. Many people package FJs and 4th gens into the same group. They are similar, but when it comes to the rear diff... big difference. The 4th gens and older FJs will break the rear diff pretty easy. The newer rear diff seems to be much stronger. I've seen many broken Toyotas.. Still have not seen a 5th gen rear diff fail.

Good point. The 4th Gen and older FJ's had the 8.0 rear, while the 5th Gen has the 8.2. I haven't seen a broken rear diff in a 5th Gen either, but I have seen broken CV axles.

 

[wfo9]

Good point. The 4th Gen and older FJ's had the 8.0 rear, while the 5th Gen has the 8.2. I haven't seen a broken rear diff in a 5th Gen either, but I have seen broken CV axles.

No doubt Cvs are the weak point, but that is somewhat a blessing as they are easy to replace on the trail..... They still seems better than the 4th gens and early FJs as there was a revision.... RCV had some at one point... but they had problems with the boots leaking. It should be pretty easy for them to make some that are bomb proof... but then the diff breaks ;-(

So it feels like SAS would be the smart option at that point. The IFS works fine for crawling... If you need to use momentum and a lot of wheel spin. Solid axle is the only way.

I think I know where you probably wheel often Barnwell? I've done every trail there (in my trail rig). even dWoody or whatever it is called. That type of terrain is very solid axle oriented.. All that loose crap that just falls apart under you... Still have red dirt in my rig....

Attached picture of my buddy going up Dwoody. I did it to, but he screwed up with my phone and I got no video or pictures ;-( Talk about a trail that has gotten harder.... Shit is scary now. We even got another friend of ours up in an FJ80 on 37s. I'm still shocked he made it.

 

[yosh2000]

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

what are your rpms at 80 mph in 4th and 5th gear?

 

[BigredTEX]

No doubt Cvs are the weak point, but that is somewhat a blessing as they are easy to replace on the trail..... They still seems better than the 4th gens and early FJs as there was a revision.... RCV had some at one point... but they had problems with the boots leaking. It should be pretty easy for them to make some that are bomb proof... but then the diff breaks ;-(

So it feels like SAS would be the smart option at that point. The IFS works fine for crawling... If you need to use momentum and a lot of wheel spin. Solid axle is the only way.

I think I know where you probably wheel often Barnwell? I've done every trail there (in my trail rig). even dWoody or whatever it is called. That type of terrain is very solid axle oriented.. All that loose crap that just falls apart under you... Still have red dirt in my rig....

Attached picture of my buddy going up Dwoody. I did it to, but he screwed up with my phone and I got no video or pictures ;-( Talk about a trail that has gotten harder.... Shit is scary now. We even got another friend of ours up in an FJ80 on 37s. I'm still shocked he made it.

Yep, Barnwell is the home park, but I hit Bridgeport just as often and spend a few weeks each year is SW Colorado.

I've done most of the trails out there, either in my rig or as a passenger. Majority of those trails can be done by a lifted 4Runner on 33's and a rear locker as long as you don't mind body damage. Lots of off-camber. I've done D'Woody a few times as a passenger in a buggy and have seen a lot of built, early pickups do it, but all on straight axles and at least 37's. My son is about 75% complete on an '89 SAS'd 1st gen. It's sitting on 35's now, but will end up on 37's by the time it's running.

 

[BigredTEX]

what are your rpms at 80 mph in 4th and 5th gear?

Follow the link I provided in one of the above posts.

 

[yosh2000]

Follow the link I provided in one of the above posts.

I have down that. I was asking for real world rpms, not calculated ones.

 

[fattire]

I have down that. I was asking for real world rpms, not calculated ones.

The calculators don't lie but since you don't believe in math...

I run (roughly) 2800 RPM in 5th at 83 mph on worn 33s. Sometimes higher RPMs. Sometimes lower RPMs. Depends which way the wind is blowing. Literally. There's also no such thing as a flat road which will impact it as well even with the torque converter locked there will be variations.


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[yosh2000]

The calculators don't lie but since you don't believe in math...

I believe in math, but I also know the difference between published (calulated) values and real world values...as you pointed out

 

[fattire]

I believe in math, but I also know the difference between published (calulated) values and real world values...as you pointed out

Weird....calculator puts me at 2759. Glad I double checked that.


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[yosh2000]

Almost 2%, huge difference! This is why I asked.

 

[fattire]

Almost 2%, huge difference! This is why I asked.

Okay. I'll admit I LOL'd at this


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[BlackWorksInc]

I believe in math, but I also know the difference between published (calulated) values and real world values...as you pointed out

Yes, but there's more variables to account for if you're trying for "Real World" values. The only way you'd get accurate, repeatable real world results is to set up a couple test vehicles and consistently drive them the same way every time for a set period. That is of course you've controlled all other variables that could influence and exceed your error margins.

 

[wfo9]

It's just the tire size that make a difference. The calculator can't know the exact diameter... When I put in the exact measured dimensions of my tires... it matches my gps perfectly. Don't forget your spedo might be off . Speed is overstated from the factory in my experience. 33s usually make it match real world. But we are taking about very minor differences here... 34s and 4.56 seem like a perfect match to me.

 

[fattire]

It's just the tire size that make a difference.
...
Speed is overstated from the factory in my experience. 33s usually make it match real world. But we are splitting hairs here for no good reason...

Absolutely correct on both accounts.

...but the RPM difference will have a big impact on highway fuel economy. My personal experience after the regear is a slight improvement in town and a slight drop on the highway.

That's exactly what you'd expect as well.



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[BigredTEX]

I have down that. I was asking for real world rpms, not calculated ones.

It is very accurate to real world. Calculator says 74 mph at 2500 rpm and I show 75 mph with GPS. Speedo is showing approx. 71 mph, which I know is indicating slow due to tire size.

 

[MarcWithFatbobs]

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

Did you end up getting yours done?

I work at @Fat Bobs Garage and am probably going to do mine in my 4runner this spring before I start hauling my trailer.

I am interested in seeing if you ended up doing this, or if we can help you get it done.

Let me know!