Jetboy
New member
Apparently there's some issues with the hosting that I was linking to. Let's try this:
Potential 4.10 Gearing Option
- Thread starter Jetboy
- Start date
Apparently there's some issues with the hosting that I was linking to. Let's try this:
Jetboy
New member
It's a 10% difference in gearing. It's roughly the same effect (in reverse) as going from a 32" tire to a 35" tire. Some people don't think a 35" tire would be a meaningful enough difference to regear. Some do. This is mathematically a near identical change. I suppose it just depends on what you're looking for. Going to 4.56 is equivalent to going to about 39's. For me - gearing for 39's so I can run 33's isn't quite what I'm looking for. Gearing for 35's, but running 33" tires seems more in-line with what I use it for. YMMV.
Just for reference as a comparison.
Going from 32" tires to 35" tires, the difference in effective gearing is 9.3% (going from 31.6 tire height to 34.5 is 9.2%)
Going from 32" tires to 40" tires is 25%
re-gearing from 3.73 to 4.56 is 22.5%
3.73-4.10 is 9.9%
For a stock tacoma with 4.10 to 4.56 is 11.2%
For a stock 3rd gen 4Runner or Tundra with 4.30 diffs, going to 4.56 is 6%, going from those to 4.88 is 13.4% and is pretty common. Going all the way to 5.29 is about 23%. So going from 3.73 to 4.56 is roughly the same change as 5.29's in a 3rd gen. Is that too low? It just depends on what you're wanting to do with it. I have 5.29 diffs in my FJ40 and they're just right IMO for 39" tires.
Edit: also FWIW - if we had a 6 or 8 speed transmission, the deeper gearing would be far less of an issue. The lack of a lower OD ratio resulted in pretty low MPG on the highway. What it feels like and what is efficient are often two different things. The transmission should downshift on hills. If it doesn't - the gearing probably isn't right for cruising on flat ground. What isn't ideal is running down in 3rd gear frequently. Or not being able to maintain 5th gear on flat ground at highway speeds. Too low of gears are also often slower and less efficient even when they feel faster. as an example - (skip to the end where they remove all the weight from the low gear'd one and it's still slower than the stock gearing)
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I'm almost with you - here is simple chart that sums up what is holding me up.
Maybe this oversimplifies it or maybe you don't even agree with the chart (stolen from tiresize.com/gear-ratio-calculator/).
But this amongst other things is what convinced me we should have been around 4.11 stock.
And re-gearing towards power/performance or increased tire size you'd walk up to 4.27 or maybe 4.56.
I think I'd want to keep it under 3000 RPM at 65, so I'm hesitant to embrace 4.56.
I recognize these aren't Toyota numbers and I don't know all the pinion/tooth details, but you briefly mentioned a 4.30 option.
It seems that would be the perfect re-gear.
You gain power/performance, but don't cross too far into the high RPM zone for those of us who want to drive 80mph.
4.10 with stock (but I can't imagine re-gearing yet keeping 265)
4.30 with 33
4.56+ if you go big or can embrace the RPMs
Jetboy
New member
FWIW - that gear ratio chart doesn't really have much application in modern vehicles. It's based on a 1:1 drive ratio - I don't think any current vehicles from any manufacturer still have a 1:1 ratio top gear. But it is valuable in the sense that it shows relative changes in tire and gearing and how they compare. I just wouldn't put much or any value on the colors or the representation of how they translate to performance. Other than transmissions, it also doesn't necessarily match our engine's attributes. I have no idea what engine they were using, but I'd guess an older small block chevy.
I think the 1GR has a pretty big efficiency cliff at higher rpms. But I don't know exactly what a BSFC map looks like. Just from my experience - I had a big drop in mpg going to 4.56 diffs with 33/34" tires (I have a set of both sizes that I alternate between). 2 or 3 mpg difference to me suggests that the engine is working harder to do the same thing with the 4.56 diffs. Part of my logic here is that if I'm going to accept 13 or 14mpg - I'd probably rather have a LC200 that has 400hp and gets 13mpg. So I went back to 3.73 and started planning on swapping around to a different platform. It's mostly an issue now of the market being really tight for LC200's and haven't found a decent deal on one. And I'm kinda waiting to see what the new LC300 is and/or the new Tundra hybrid.
As a comparison I rented a Ram 1500 with the 5.7 hemi for 2 weeks. Drove 2700 miles, of which around 1500 were towing a 24' travel trailer. I averaged almost 18mpg for the total trip. Unloaded I was getting 20+ mpg. Even towing that big trailer I got better mpg than I do towing my little teardrop with the 4Runner. And it has the same 33" tires I have on my 4Runner.
I was kinda hoping 4.10 might be a nice fit between the too high 3.73 and the too low 4.56 ratios. If the only tire options were 32 or 39" tires, that would seem like a huge gap. And the same relative difference is what we have now for gearing. Something in the middle would be a good alternative IMO.
And as a bonus - if anyone wants to compare what 4.10 gears feel like - you could just go test drive a new 4Runner. It should be really similar in net gearing to 34" tires with 4.10 gears. Almost exactly the same highway rpms.
I think the 1GR has a pretty big efficiency cliff at higher rpms. But I don't know exactly what a BSFC map looks like. Just from my experience - I had a big drop in mpg going to 4.56 diffs with 33/34" tires (I have a set of both sizes that I alternate between). 2 or 3 mpg difference to me suggests that the engine is working harder to do the same thing with the 4.56 diffs. Part of my logic here is that if I'm going to accept 13 or 14mpg - I'd probably rather have a LC200 that has 400hp and gets 13mpg. So I went back to 3.73 and started planning on swapping around to a different platform. It's mostly an issue now of the market being really tight for LC200's and haven't found a decent deal on one. And I'm kinda waiting to see what the new LC300 is and/or the new Tundra hybrid.
As a comparison I rented a Ram 1500 with the 5.7 hemi for 2 weeks. Drove 2700 miles, of which around 1500 were towing a 24' travel trailer. I averaged almost 18mpg for the total trip. Unloaded I was getting 20+ mpg. Even towing that big trailer I got better mpg than I do towing my little teardrop with the 4Runner. And it has the same 33" tires I have on my 4Runner.
I was kinda hoping 4.10 might be a nice fit between the too high 3.73 and the too low 4.56 ratios. If the only tire options were 32 or 39" tires, that would seem like a huge gap. And the same relative difference is what we have now for gearing. Something in the middle would be a good alternative IMO.
And as a bonus - if anyone wants to compare what 4.10 gears feel like - you could just go test drive a new 4Runner. It should be really similar in net gearing to 34" tires with 4.10 gears. Almost exactly the same highway rpms.
I was tracking that most sites/charts were using 1:1 as their baseline.
I wasn't sure why other than easy math-comparison.
I've been driving around in S4 to get the 1:1 feel.
It's been okay until you get a 3rd gear downshift on a big hill at speed.
I guess the BSFC is what is missing - what is the target?
And do you want max efficiency or an acceptable % with increased performance?
The colored blocks were pretty representative to my unscientific "feel and sound" - that's my <3000 RPM.
I tried to track mpg, but my driving is just too variable.
I'm thinking your 4.10 target is a little too low.
Only gets back to stock set up - so probably overly efficient-centric.
Certainly beats 3.73, but if you are going to do it, I'm thinking do what should have been done from the beginning.
So...
I think you need to spend your time & money testing 4.30 for us and getting a company to build and warranty them.
If you want to do both 4.10 and 4.30 that would be great too.
Just let us know where to send our $ once it's all worked out.
Jetboy
New member
4.30 would be a good ratio for 34" and up tire size. It would be more expensive though. There are heeps of 4.10 front OEM diffs out there from tacomas that you can find in salvage yards and could swap in easily and cheaply. I can usually buy a complete OEM front clamshell for $250. The 4.30 front 8" clamshell exists as do aftermarket thick ring gears, but more expensive.
I got lost in my own "ideal" thoughts...I re-read your original post and I get it now.
- front: Tacoma OEM 4.10 gears
- rear: vendor to carry them with full service behind it instead if they were more like $350/set
Familiar 4.10 with a lower parts cost does make sense.
Particularly since I lack the experience, space, and patience to do this myself and will have to hire a pro.
And bonus $ - add a locker since I have a SR5
2021nightshade4x4
New member
“I’ve been driving around in S4 to get the 1:1 feel.”
I love when people really get down into the nitty gritty of the driving experience (sometimes even, but not necessarily the technical side of things, too).
Some drivers put serious time into designing their vehicle and making it their own. Maybe you have “THAT hill” on your commute where the 4Runner downshifts, seemingly unnecessarily.
Take control, increase your ratios. The supercharger for 2020+ model years doesn’t have a timeline for release. Toyota will not be putting a V8 in the 4Runner any time soon. The only thing that I foresee happening is a turbo 4 and a 9 speed made by ZF [emoji1785]
Since the ECM on these is locked down, we only have control over the physical things not part of the feedback loop reporting to the system. Gear sizing is one of those few things. Heck I’ve seen posts from people installing 4.56 that wish they did 4.88.
Go all the way! LOL
Sent from my iPhone using Tapatalk
Jetboy
New member
I'll send you a PM later when I have a little more time. The short answer is that I didn't want to buy 200 sets. But they'll make em for anyone who wants to put in a minimum order. There's no meaningful tooling fees or design costs since the forgings for existing ratios are useable. They confirmed that. It's all automated from there. Software generates the tool paths. Just the minimum order to do a production run.
FloridaUnderground
Junior Member
Good Info
So I'm running a 33" now, 255/80-17, so the 3.73 is fine, but my next tire will likely be a 255/85-17 if I stay skinny or a 285/75-17 if I don't which are close to or above the 34" mark, so considered the 4.10 option. I'd want to do the front air locker at the same time, but where would you find both the front and rear re-gears for 4.10's, I see tons of 4.56's and 4.88's but hardly any info on the net about 4.10's. I know it's not a huge jump but it's still 9-10% and should that that larger size tire.
So I'm running a 33" now, 255/80-17, so the 3.73 is fine, but my next tire will likely be a 255/85-17 if I stay skinny or a 285/75-17 if I don't which are close to or above the 34" mark, so considered the 4.10 option. I'd want to do the front air locker at the same time, but where would you find both the front and rear re-gears for 4.10's, I see tons of 4.56's and 4.88's but hardly any info on the net about 4.10's. I know it's not a huge jump but it's still 9-10% and should that that larger size tire.
mrblah
Senior Member
none that i am aware of for 4runners, but that was a few years ago. I dont think anythings changed.
I ran 4.88's w/ 34's just fyi.
FloridaUnderground
Junior Member
Where does one buy either 4.10 or 4.30 gears for the current 4Runner or GX?
FloridaUnderground
Junior Member
How are your highway rpms at say 65 or 70?
This is an interesting discussion. I found this thread after searching for mild regear options on 5th gens. This sudden interest of mine is peaked after finally getting our bone-stock 2024 Pro out on the interstate to stretch it's legs.
I was surprised to see how much the 4Runner struggles and downshifts on subtle hills at 70-75mph even at sub 1000ft elevation. Granted, I know these things are like bricks going down the road, and wind resistance is exponential, but I feel like my 4.30 gear ratio 3rd gen takes hills better at speed.
Even though I have zero intentions of modifying our Pro with larger tires or heavy gear, I would still consider a 4.10 regear simply for drivability. Moral of the story is, I think the 5th gens should have came with 4.10 as stock gearing.
Are there any updates to the lack of 4.10 gear suppliers?
I was surprised to see how much the 4Runner struggles and downshifts on subtle hills at 70-75mph even at sub 1000ft elevation. Granted, I know these things are like bricks going down the road, and wind resistance is exponential, but I feel like my 4.30 gear ratio 3rd gen takes hills better at speed.
Even though I have zero intentions of modifying our Pro with larger tires or heavy gear, I would still consider a 4.10 regear simply for drivability. Moral of the story is, I think the 5th gens should have came with 4.10 as stock gearing.
Are there any updates to the lack of 4.10 gear suppliers?
