i know....another re-gear post. 4.56 vs 4.88 on 34s

have already read through others posts on the topic, there's not a ton of feedback/agreement though on which ratio for 34's. Everyone seems to think 4.88 for sure on 35s, runnin 33's then go 4.56 (or just stay stock).

looking for anyone with actual experience re-gearing on 34's. Currently running the Toyo R/T Trails in 285/75r17. Deff not stock weight, but I wouldn't call it heavy either since I try to keep weight to a minimum. I am running dual batteries/compressor/fridge/awning/shower enclosure/RTT (although its a GFC superlite), and then when underload waterports, rotopax, gazelle tent, etc. No steel bumbers, skids or anything thats adding a TON of weight.

I'm in the southeast, offroad is strictly mountains and alot of sand.....no rock climbing. daily drive is a mix of highway and local roads.

anyone here do 4.56 on 34s and really wish they had gone higher? anyone go 4.88 on 34's and hate life on the interstate?

 

I have 4.56 and it increased my highway RPM 400. If I was on 34s going 4.88 would have been my decision.

Best mod I have done improving driveability. I can increase speeds going up inclines now staying in 5 not downshifting.

 

I've owned vehicles with 3.07, 3.55, 3.73, 4.10, 4.88 running between 29" and 35" tires. For me, the deeper (lower gearing, numerically higher) the better. I realize there is a tradeoff, but I really think the increase in torque that lower gearing provides is worth the loss of mileage, if there is any. In some cases, lower gearing, while obviously raising RPM, is more efficient. There is less downshifting, or hunting for gears (in the transmission) and this may lead to no, or little, loss in mileage. The reality is you'll probably see a decrease, but it may be lower than you think, especially dependent on where you drive.

The other part to consider if off road. Yeah, lower gears are better in rocks, but it's also better on steep inclines/declines. The torque multiplication is pretty small between 4.56 and 4.88, but it helps, especially considering the transfer case gearing is high in 4Runners.

Although I don't have experience with that gearing in a 4Runner, based on my experience with a handful of other rigs, if I had the choice, I'd run 4.88 with 33" tires (I have run this combination by the way and it was great).

 

thanks....so you are on currently running 33's with the 4.56? 285/70/r17?

 

I am the only 4r owner regeared on 265s to my knowledge. Started out my build anticipating the regear would be needed. With weight savings in mind every mod and keeping 265s it didn't work for me. Interstate speeds, crosswinds, mountain inclines downshifting drove me nuts. Going to 33s next now that I bit the bullet on regear.

 

I chatted with the guys at a shop and the first questions they asked were:
Towing?
Roof top tent?
Cabinets?
-no
Daily driver?
- yes and I drive the freeways a lot over long distances

felt I should try a tune first and see if that solved my issues and if not talk through it again.

btw, tire diameter for me is 34.7

 

Here's the thing about a tune...how do you get that performance, and how much performance is it?

The mechanical advantage of a re-gear is 22% more torque with 4.56 gearing, or 30% more torque with 4.88 gearing. That's like getting 340 - 360 lb-ft out of a tune. Can you get that from a tune?

 

While I can't say I went to 34" I did Regear to 4.88 with stock tire size (Falken AT 3). I tow a small travel trailer in the Arizona Mountains frequently and average around 15.5 mpg. I tend to drive in S mode in the mountains to lower the chance of shifting so often.
The system seems to work well for me.

 

For a 4Runner it's pretty much this if you don't commute at 80 all the time. That much extra gear is more efficient around town, far better off road, and the extra kick for passing is fantastic. It's just not great for mileage above 70.

If we had better/more gearing like the Tacos and Jeeps, you can go even deeper. There were some of the Jeep guys running 5.13 and 5.38 on 35s with the 8-speed.

 

On my last 4Runner I ran 295's with 4.56's. Full front bumper, skids, sliders, roof rack.. no real additional cargo weight. I wished I went with 4.88's. If I go past the 285's I'm running on my current 4Runner, I will for sure go with the 4.88's.

 

I think a tune would be more about tweaking where the power comes in/ fuel delivery and adjusting shift points so the truck wouldn't feel as lazy. I've always had good results getting motorcycles tuned, and would be curious about getting my 4Runner tuned. But that will probably never happen, because if something goes wrong, that's a lot more out of the wallet than a bike engine, lol. But yes, you are absolutely correct.. those numbers would never happen with a tune.

 

For those who have had their 4Runners re-geared, what kind of costs were involved (all in)?

I have a 2022 ORP on 33s. I do not do a lot of off-roading and it is usually only driven on weekends. I’ve had it almost 2 1/2 years and only have 9K miles on it (have company car for work) so I am not really concerned with fuel mileage.

 

I run 456 on 33s, been super happy with it and also have the OTT, if you go to 34s and have a bunch of weight just go 488s. You might end up on 35s one day so your there on gears anyway. I didn't go with 488 because I have a Maggie SC so no need to screw anymore with RPM.

 

I have 295s mainly on highway speeds and when I asked about re gearing at a shop, they said a good tune would be fine for me since I have no extra weight or aren’t towing anything.

im planning to upgrade to 35s and the shop owner had a 4runner on stock gears with 35s and all he did was a tune as well since it’s his daily.

 

265/70/17 = 31.6"

A jump to 35" tires is a 10% difference, so you're essentially adding a taller gear (the tire) by 10%. Overcoming that with a tune, not sure that's gonna happen. Add the additional tire weight into the equation and I would do at least a 15% increase in gearing to get the lost torque back. 3.73 (stock gearing) * 1.15 = 4.29. You'll 4.29 to just to be at stock power with 35" tires. The 4Runner already has anemic power with stock gearing, and the crawl ratio is way to high. I don't think the shop owner wheels his rig much. A 4Runner with stock sized tires should have at least 4.10/4.11, and I'd go with 4.56 gearing at minimum for 33" - 35" tires; better yet 4.88.

If you are doing differential/gears anyway, you should consider a limited slip/locker since the diffs will be apart anyway. Only really helps off road, but if you ever think you'll spend more time off road, now is the time.

 

North of 3K at a minimum. All in.