When to Regear??

When do you really need to regear??

I currently have about 450 pounds of armor and winch bolted up. I’m running 33s (285/70/17 and considering 34s (285/75/17)

Will a regear really be necessary with a 34” tire? 4.56 or 4.88?

Any real world experience with this?

Edit: Real world experience would be:
-Why did you regear? Gear hunting, mileage, better crawl gearing, more torque?
-What is your comfortable cruising speed on 34s before and after a regear?
-Did fuel mileage increase or decrease. Theoretically, city would more efficient, hwy would be less efficient. Is this what you experienced after regearing?
-Include some context: Do you carry lots of gear, do you live in a mountainous area, do you tow regularly? This would change your need for a regear drastically.

Thanks guys!

 

I am running 34s, steel bumper/winch and full set of skid plates. The truck is doing perfectly fine. If I keep the speed limit, I can get 18.5 mpg on the highway.
Don't let anyone touch your diffs! Spend your money on some more cutting to improve your angles

 

Love this. Thanks man. Putting my mind at ease!

 

That is very steep, camera is lying. My truck did that with little bit of throttle. And I had some crap on top too. You'll be fine.

https://youtu.be/qlbxNb5LjO0?feature=shared

 

Very nice! Funny how pictures and video never tell the whole story when it comes to wheeling. I’ve realized that if it looks gnarly on camera, it’s 100x worse in person

 

So I saved you some money, now go and buy this with it.

 

Tbh after the tires I will be getting a storage system from Finn fab. Then a drawer system. Then C4 high clearance additions. Then I’m tubing the rear bumper. Similar to 80% off road kit. This will gain me some departure angle so I’m not ripping off the rear bumper all the time

The money you saved me has already been allocated xD ​

 

There are plenty of videos online about this topic. Suggest you get to understand the technical details on why regearing is beneficial when adding more weight and going up on tire size. I say it makes a big difference and your transmission will thank you as well. I run 456's and on 33s and plenty of other gadgets underneath.

 

Need is subjective.

I'm on 295/70/17 (33.5") MT's in the summer. 80% full armor, roof rack, etc. I tow, and off-road regularly.

It's fine if you're patient.

It's definitely slower than stock. So, if you're not thrilled with the acceleration now, you're going to hate it on 34's.

Another consideration is that our crawl gear (4lo, S1) isn't great to begin with, and bigger tires make it worse. If you do a lot of technical off-roading, and/or steep descents where you want to rely on engine braking, a regear will be beneficial here.

Also, as @ChessGuy mentioned, it will take stress off of the engine and transmission. It's definitely worth watching some videos, and reading whatever you can find on the topic to make your own decision.

 

Thanks for assuming I've done no research on this topic... I have done plenty of research and gear ratio calculations. I'm a quality engineer by trade so I'm detail oriented to the point of annoyance.... I'm asking for real world experience on this.

Did you regear because someone said you needed to? Or was it because you didn't have enough power, gear hunting, or mileage? Did you want more control while wheeling and lower gearing gave you that? After the regear what is a comfortable cruising speed? I can still cruise at 90-95mph without issue with my setup. Is that possible on 34s before and after a regear? These are the questions I wanted answers to. Gear ratio calculators will not answer these questions. Only real world experience can.

I've heard some people need regearing for 33s and in my opinion that's complete rubbish. I've run 33's with all the armor, loaded up with a passenger, and 400+ pounds of gear and the worse thing I experience is some gear hunting. Which can be solved by putting the transmission into sport mode.

I've also heard people say 34" is a sweet spot. No need to regear for that tire size.

Just wanted real world experience from someone who has done it. Give me anecdotal evidence. Pros and cons you experienced.

 

Thanks for the detail. What was the deciding factor for you personally?

Edit: I imagine towing makes a huge difference as well. I could see that being a big factor.

 

I'd sugguest try a tune first if you haven't. Hit up kdmax, yotawerx or ott.

 

I haven't re-geared, yet.

But, I'd say my biggest complaint would be the low range crawl gear. I'd love to have a little more control, and better engine braking. It's been working fine, but I think a re-gear would definitely improve the off-road experience.

Next would be the nonstop downshifting on the freeway. With the 295's on, I almost never use overdrive. I leave it in S4 and and get like 13 MPG at higher speeds. This is still nicer than having it downshift repeatedly.

Still, depending on your driving style, you might not find it necessary. You could always do the tires and just see how it performs.

I'll say that, if I were going any bigger with tires (34-35"), I'd surely want to re-gear. If it was cheap, I'd have done so already.

 

This is another good point. Some of these tunes can really wake up these engines.

 

Very fair.

I'll ask you this, even on the factory tires, the crawl gear was lack luster. When I moved up to 33s I did not notice it get much worse. Did you notice it get significantly worse?

Also, can you still cruise at 70-75mph in overdrive? Do you downshift for hills only or just run in S4 all the time?

 

I can't say for sure, because I was very new to off-roading when I got the 4Runner. So, I have progressively attempted more difficult and complicated obstacles as I was also adding weight and bigger tires.

I can say for sure that I would like a better crawl gear, whether it's through a re-gear or a crawl box.

I can actually cruise in overdrive, at lower speeds. If it's fairly flat, it's not bad at 55-65 on 2 lane highways. It still downshifts, but not as bad. It's the hills, and higher cruising speeds that really make it suck.

 

I like to recommend them. As it worked for me. Really helps in the lower rpm range(2500ish rpm). The price of a tunes is like $500 compared to $3000(regear).

Also weight is a huge factor. Keeping your wheel/tire weight down. Really helps move these sluggish 4runners.

 

Which tune do you have? I've been kicking the idea around for awhile.

 

I'm running kdmax 9.0(which the have a updated 10.0 now)

But from what I heard and discussed with others. They are all very similar. So which ever tuner is local to you go with them. That way if they update or you want them to adjust something you don't have to drive far.

For the money its worth it imo.

 

So try out some 34s. If needed, get a tune first to address the lack of power.

Have a regear in the cards if it's unbearable.

Any other advice, opinions, experiences?

 

Stick with skinny 34s to save your power steering pump, but I’d still regear. A tune will help with the throttle delay

 

285/75/17 skinny enough? I was thinking of sticking with Nitto Ridge Grapplers.

 

285/75's aren't skinny no, more like 255/80 or so.

Power steering pump definitely a consideration when moving up to 33.5" or true 34's.
But I'm more in the do it now and ask the 4R for permission later camp haha
@1SilverRunner you got a solid list of mods on your build and coming up next. I too am eyeing 34's, actually even 35's. Not needed yet, but it will be the next (second) tire purchase.
I say have a pedal commander device, get a legit tune, go big on the tires like 295/70 or 285/75, leave the gears Toyota OE. I'm considering saying yolo after 1" body lift and running 35"s, then drop back to 33 in the future.

For ppl running 34-35's what do ya'll think about going the route of a Marlin Crawler Tacobox instead of regearing both axles?

 

I say save the regear when you go with 37s eventually. Not worth it with 34s. Regear is not going to make your 4Lo/1st as slow as Wrangler Rubicon's, so don't sweat it. The biggest hurdle in your way on the trail is your truck's body angles, they will stop you, not your gear ratio.

 

^ tacobox slows to near Wrangler range ?

 

Typed that out on my phone too fast. I meant skinny 34s to save the steering rack. I’ve heard more regrets from people moving to 35s than anything else

 

This is terrible advice.

Almost nobody here is going to "37's eventually."

It's not just about the crawl gear. It's about lightening the load on the engine and transmission, improving fuel economy, and overall performance.

More. It is essentially 4lo/lo. It brings the total gear reduction to ~6.6:1.

 

Dude lol. 34s are nothing, engine and transmission will be fine.

 

By far, quality engineers different than mechanical engineers, but let’s leave the math alone for now and focus on the real-life examples.

1. Imagine going uphill in your bicycle, you have a certain cadence and good ability of how much energy your legs need to put out in performance so you get over the top. Now, imagine you go up the same hill but on larger (heavier) tires, on the same bicycle. You could still go up and probably complete the distance, but your legs and heart rate would have a different profile (performance) than on the stock base example. Third test, now add a bookbag to your back and a water bottle up front, go up the same hill and see. You get the point on this exercise.
2. The 4R was designed out of the factory with certain specs so that it meets emissions, mpg, torque, transmission, engine, and others. When you start going up on tire size these specs and strains alter the baseline. A good quality guy will see this, something will change on the base if there is a change.

Your questions:

Did I regear because someone said you needed to? No. I did the math and validated later with the before and after tests. It is all about understanding your baseline, and then benchmarking this when you add/remove components from the rig.

More control while wheeling? Yes, most definitely, regearing gives you the ability to slowly go thru an obstacle where you are not on/off the gas all the time. You are not jerking the system at all times; the low-end torque profile is completely different than stock.

Cruising at high speeds after regearing is possible, a tune can remove the constraints of the upper limits, but why are you trying to go so fast on a 4R. If you need to go faster, you need a different vehicle then.

I respect your experience on 33s, that works for you, it wasn’t rubbish to me, it actually restored my setup, as I also have a supercharger, but that adds another set of complexity to the math.

Look, the ultimate test for me was this. I ran the ScanGauge-2 tool to monitor the transmission temperatures for a 10hr trip I took, on average, my trans temperatures were 215 to 220F, I took the same trip with after regearing, and the range went down to 208 to 215F, a pretty good reduction in temp, I downloaded the data and plotted it againts mpg and others, I was sold then.

I think I have raised my case – good luck to your setup on 34’s. If you are ever in the Houston area, hit me up and I can let you borrow mine to compare performance.

 

5 degrees, I wouldn't lose my sleep over it