Let the fun begin! (1 Viewer)

[sleeoffroad]

Yes, you can regear and also do a locker, but you have to essentially get a differential from an older truck to do so.

 

[RobW0]

Yes, you can regear and also do a locker, but you have to essentially get a differential from an older truck to do so.

Question for you. Is it the regearing, the locker or the combination of the two that needs this? Can you re-gear without the locker on the front?

 

[nor_cal_cyclist]

@RobW0 are you finding the stock gears a bit lacking after your tires, rack, sliders and tank?

Pretty sure you can regear without the locker - but if in the diff anyway - why not???

 

[RobW0]

@RobW0 are you finding the stock gears a bit lacking after your tires, rack, sliders and tank?

Pretty sure you can regear without the locker - but if in the diff anyway - why not???

I have not gotten to get it off road yet, but have put a lot of interstate miles on it the last month. I find that it does seem to shift up and down a fair amount when cruising at 75 on the interstate. I am looking at doing some towing in the future so I am thinking about doing a re-gear.

 

[sleeoffroad]

Question for you. Is it the regearing, the locker or the combination of the two that needs this? Can you re-gear without the locker on the front?

There is no gearsets for the 2016+ that fits the rear third member or front carrier in the front diff for the 2016+ truck. So if you want to regear you need a rear diff from an ealier truck as well as a carrier.

Same is for the lockers. However not sure 4.88's are a good match for the truck. I think that is way to much gear. You would be to use the old truck diffs (3.90's) that would be a better ratio than the stock 3.30's in the 16+

 

[bloc]

IF you do regear, try to shoot for OEM toyota gears. @Taco2Cruiser ran Nitro gears and said they put off a lot of metal.. said he'd run OEM in the future if possible. @bjowett managed to find quite a few ratios from toyota.. even e-locker options.

 

[nor_cal_cyclist]

There is no gearsets for the 2016+ that fits the rear third member or front carrier in the front diff for the 2016+ truck. So if you want to regear you need a rear diff from an ealier truck as well as a carrier.

Same is for the lockers. However not sure 4.88's are a good match for the truck. I think that is way to much gear. You would be to use the old truck diffs (3.90's) that would be a better ratio than the stock 3.30's in the 16+

Do you feel this way for an "overweight" 200 spending much time at elevation in the Sierra's? Sounded like the change was just a part specific to the 16+ from Nitro, but if I'm replacing the entire carrier with an earlier unit...am I truely gaining anything? Really trying to get this figured out...before creating an expensive mess I have to clean up later.

 

[slowride]

Hey nor cal,

So is your rig in Indiana already???

Jeff

 

[nor_cal_cyclist]

@slowride yes - my truck arrived at Ed Martin last Friday (I believe) and was at the tint/PPF shop this past week in Indy. Back at Ed Martin Toyota currently for the lift/bumper/tires/roof rack/LRA...and planned gears/lockers (but really questioning that decision right now). Hoping to either fly out to get it or have it shipped out west by end of Sept (LRA due to arrive from down under mid-Sept).

 

[slowride]

Hey nor cal,
Good to hear... I'm in southwest Ohio and getting organized with my list of mods and a time table to get it accomplished... My main concern is that the parts/mods are installed correctly... The last thing I want is for the new suspension mods to be clunking around because they were not properly installed and then have to guess what part is now causing the problem...

Your rig is looking good, it's fun to watch the progress...

Everyone speaks highly of Ed Martin's and Eric, so I'm looking forward to how it all goes for you...

Thanks

 

[Eric Sarjeant]

I really appreciate all the feedback on this thread. Really awesome to see the community chiming in for the betterment of the build.

We did Nitro 4.88s on a 2019 200 in April (with ARB air lockers), running 35’s (per the customer) when I drove it 500 miles at variable speed before the oil change, it didn’t have the 35’s on yet (wheels were back ordered). So my baseline is not really there on how it was “supposed” to be in relation to stock gears/tire/wheel defaults.

With that said, we did run into the issue of the gears fitting, but Nitro has the third member available and we had it overnighted and no issues past that point.

I will be the first to admit, I’m not a gearing expert, but I do agree with you guys (as the real-life experts), we jumped too quickly on the 4.88s when specing out this build. Nitro shows 4.30s on their site, but after calculating further, I’m wondering if those are too big, even if “super heavy”.

Help me think out loud here:
Calc.... 285/60-18=31.5
33.5/31.5=1.064
3.307x1.064= 3.52
Do you want basically the next gear size higher than 3.52 to stay close to stock gearing. So prob 3.70???

Does the two overdrive gears/ECT help compensate for the RPM while cruising?

We could go up in tire size too still, we’re sticking with 18” (TRD PRO BBS) wheels.

As Nor_Cal mentioned, we’re slow walking right now because the LRA is on a boat still. So we have time to correct. I truly appreciate the insight/concern.

Advise welcome.

 

[Eric Sarjeant]

Reference materials:

 

[Eric Sarjeant]

Reference photos:

 

[bloc]

One thing to consider is that with larger tires and especially armor, not to mention all the extra weight.. lower effective gearing often works out better. Said another way, the engine turning more RPMS in a given gear at a given speed helps produce some more HP, which helps deal with all the extra drag from the tires/lift/armor/rack/etc.

Toyota designs even these big things to have a relatively low drag coefficient, and to make fuel efficiency as ideal as possible they gear the truck to make just enough RPMS to make just enough horsepower to push it through the air at that speed, plus a small margin.

So I wouldn't be looking for gears that exactly compensate for the tire size. I'd look for gears that go a step or two beyond that, to keep the transmission happy on the highway (stay in torque converter lockup in tallest gear, etc).

Edit: but you can definitely go too far. Working up the math to see what RPMs you'd be turning on the freeway at a specific speed with different ratios can help out. I'll find a calculator and post it.

 

[bloc]

Also, I'd refrain from just using larger tires to correct a gearing issue. You can start to run into clearance issues, and possibly be stuck with them, unless you want to pay to regear it again.

With a gear calculator and the numbers published above..

Stock tires/gear RPM in 8th
70mph: 2017
80mph: 2306

Stock gears, 33.5 tires
70mph: 1897
80mph: 2168

3.52, 33.5
70: 2019
80: 2308

3.7, 33.5
70: 2122
80: 2426

3.909 (stock 08-15), 33.5
70: 2242
80: 2563

4.33, 33.5
70: 2484
80: 2839

4.56, 33.5
70: 2616
80: 2989

4.88. 33.5
70: 2799
80: 3199

The reason 4.88s work well in the earlier 200s is 6th gear is very tall at 0.588:1. Compare that to the 8th gear of a 16+ at 0.817:1.. very large difference.

Personally, I'd be looking at stock gears from a 08-15. 200rpms extra on the freeway to help deal with the increased drag, but not 1000 extra that will be wringing the engine's neck all the time.. and huge on my mind: OEM toyota quality. Or possibly the 4.33s if I lived at altitude.

you can play with your own combinations with the "find RPM" section of this site: 4x4 related Calculators, Crawl Ratio, Gears Tires Sizes, etc..

Edit: it's interesting to me that an 08-15 is so much lower RPMs at 70 when stock: 1716. Even with 3.90s. Shows how dramatic that top gear difference is.

Edit2: added 4.33

 

[bloc]

I don’t know if they are even available, possibly from a tundra, but just to fill out the chart..

4.1 and 33.5
70: 2352
80: 2688

 

[Eric Sarjeant]

Quick follow up. I talked to Al at Nitro today. He said 4.30 would be correct for that tire size with weight and altitude. Mathematically still seems too much, from @bloc's math which is correct. Carl (also from Nitro) advised @benc that 4.30 would be correct on a similar build we are collaborating on in October. Sure they are selling the gears (and they don't offer 3.9s), but I don't think they would lead anyone down the wrong road with their reputation.

As Christo @sleeoffroad mentioned, you have the fitting issues. Nitro does sell the referb (2008-2015) third member and you can have them build it if you exchange cores. I wasn't aware that you have to do the same with the front carrier (a detail that passed me from the March build), but we did in-fact need the T9R replacement carrier in the front, which Nitro also sells.

I threw out an option that we could "upgrade tire sizes" but forgot that the 12.5gal LRA would probably not really allow for anything bigger our 305/65/18s, so that was a dumb statement in hindsight as this build does not call for a rear bumper.

The 3.90 in the pre-2016 LC or 4.6L V8 Tundra could be an option still. If 3.90s become the best viable option/solution, keep in mind the cost would probably (significantly) exceed the Nitro's even me buying them at cost from my parts dept.

Wouldn't mind hearing a little more feedback if anyone has anything else to add.
Again, thank you to everyone for their input.

Eric

 

[indycole]

Quick follow up. I talked to Al at Nitro today. He said 4.30 would be correct for that tire size with weight and altitude. Mathematically still seems too much, from @bloc's math which is correct. Carl (also from Nitro) advised @benc that 4.30 would be correct on a similar build we are collaborating on in October. Sure they are selling the gears (and they don't offer 3.9s), but I don't think they would lead anyone down the wrong road with their reputation.

As Christo @sleeoffroad mentioned, you have the fitting issues. Nitro does sell the referb (2008-2015) third member and you can have them build it if you exchange cores. I wasn't aware that you have to do the same with the front carrier (a detail that passed me from the March build), but we did in-fact need the T9R replacement carrier in the front, which Nitro also sells.

I threw out an option that we could "upgrade tire sizes" but forgot that the 12.5gal LRA would probably not really allow for anything bigger our 305/65/18s, so that was a dumb statement in hindsight as this build does not call for a rear bumper.

The 3.90 in the pre-2016 LC or 4.6L V8 Tundra could be an option still. If 3.90s become the best viable option/solution, keep in mind the cost would probably (significantly) exceed the Nitro's even me buying them at cost from my parts dept.

Wouldn't mind hearing a little more feedback if anyone has anything else to add.
Again, thank you to everyone for their input.

Eric

I'll add an observation. I have 4.88s on my 2016 which overall is a heavy build running between 7500-9000 lbs depending on the trip. While I can't compare to 3.90 or 4.30 in my truck, I'm quite happy with the 4.88s. Low-range, 1st gear is ridiculously low and provides a lot of control on steep declines with 34 inch tires. I can understand how taller gears would be a better fit for lighter builds / smaller tires.

All that said, the truck is enormously capable without gears and lockers and I'm not sure if there's any logistical benefit to doing them at the same time as the rest of the build especially when you may as well get the hardware installed directly in the replacement carriers at your vendor of choice for an install down the road. In the meantime, enjoy the truck and determine if you really want to modify your drivetrain. But, if it's a foregone conclusion and you want it all done at once, go for it! The truck is even better with gears and lockers

Edited to add that if I had to do over again I'd probably look for the 4.30s but I wasn't aware those were an option when I did my gears. Still, no complaints with the 4.88s.

 

[bloc]

Quick follow up. I talked to Al at Nitro today. He said 4.30 would be correct for that tire size with weight and altitude. Mathematically still seems too much, from @bloc's math which is correct. Carl (also from Nitro) advised @benc that 4.30 would be correct on a similar build we are collaborating on in October. Sure they are selling the gears (and they don't offer 3.9s), but I don't think they would lead anyone down the wrong road with their reputation.

As Christo @sleeoffroad mentioned, you have the fitting issues. Nitro does sell the referb (2008-2015) third member and you can have them build it if you exchange cores. I wasn't aware that you have to do the same with the front carrier (a detail that passed me from the March build), but we did in-fact need the T9R replacement carrier in the front, which Nitro also sells.

I threw out an option that we could "upgrade tire sizes" but forgot that the 12.5gal LRA would probably not really allow for anything bigger our 305/65/18s, so that was a dumb statement in hindsight as this build does not call for a rear bumper.

The 3.90 in the pre-2016 LC or 4.6L V8 Tundra could be an option still. If 3.90s become the best viable option/solution, keep in mind the cost would probably (significantly) exceed the Nitro's even me buying them at cost from my parts dept.

Wouldn't mind hearing a little more feedback if anyone has anything else to add.
Again, thank you to everyone for their input.

Eric

From the numbers I worked up I’d be comfortable with the freeway RPMs of 4.30s. That said, Cole is a smart dude with a lot of overland experience. I personally don’t like the idea of those RPMs long term, (not so much for reliability as fuel efficiency, which I do consider for my build) but then I wouldn’t likely end up nearly that heavy either.

He does make a good point about just doing it later as the owner gathers more information about what works. Ie driving other people’s rigs to see how they perform.

 

[sleeoffroad]

Do you feel this way for an "overweight" 200 spending much time at elevation in the Sierra's? Sounded like the change was just a part specific to the 16+ from Nitro, but if I'm replacing the entire carrier with an earlier unit...am I truely gaining anything? Really trying to get this figured out...before creating an expensive mess I have to clean up later.

I had 35's on my previous 08 200 and regeared to 4.30's and never felt I needed more gear. I think the 200 can pull off larger tires better and I am not a huge fan to overgear for weight. Gears does not make power, just change RPM range and different speeds.