4.88 or 5.29 gears for my situation? (1 Viewer)

Joe Link

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Some of you are following my work in this thread. I'm realizing that if I'm going to re-gear, now is the time while I have everything apart. Not sure which ratio to go with and I could really use some advice!

- While I'd prefer a rig that can do it all (who doesn't??), I do more overlanding than hard wheeling.
- It's my daily driver in the winter.
- Vehicle is heavy (ARB bumper with winch, rear tire carrier, sliders, and a bunch of gear), and it'll get heavier as I add more (rear bumper, roof rack, etc).
- Currently running 33" BFG KO2's with around 60% tread left. If I can suffer through it I'd like to run them until they wear out, but this is a dumb reason to go with one ratio over another. Once these wear out I'm planning on going with either 35's or 37's (90% sure it'll be 37's, you only live once).
- Vehicle has factory lockers.
- I'm at sea level here in PDX.
- I'm collecting parts for a 5.3 swap and I don't want to have to regear again.

Questions
- Is there a preferred gear brand these days?
- Does anyone know of a competent gear shop in or around Portland, OR?
- Do the lockers and/or ratio choice require specialized expertise, or is it something any gear shop can do?
- Is the 37"+ and factory locker combo something I should be overly concerned with?
 

Heckraiser

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I wold go 4.88 if you're realistically getting the 5.3 swap done. Some people just dream about these things and never accomplish them.

I wouldn't be overly concerned about running 37s with stock axles and locker, lots of guys do. As long as you're not an overly hamfisted driver, should be OK.
 
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You will get both answers. Main difference is on a stock motor the 5.29 will be running about 3500 RPM on the freeway, limiting you to 65 MPH or under.

This is the reason I choose 4.88. There is another member who went 5.29 and their 80 and enjoy driving it so much they just listed it for sale.
 

80t0ylc

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NitroGears is a good choice. I've heard a lot of noise lately that the 5.29's are weaker than the 4.88's. I'd go with the 4.88's if you're serious about the 5.3 swap. I went with 5.29's because I tow an off road trailer and am keeping the 1FZ.
 
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5.29's with 37's = 9.1% actual real-world GPS verified gear/tire reduction from stock. This in no way limits your highway speeds. For instance, my rig does 70 mph (per GPS, not the speedometer) at 2700 rpm, and 90 mph at 3400 rpm. If you want to go faster, it's available.

After the lift and 37's, this is the best mod I've done. I'd be crying if I had done 4.88's.
 
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I run 5.29's and love them w/ my 37's.
I'm also on the down hill side of doing a 5.3 swap. Will see how it goes w/ the 5.3, but I know when tuning the 5.3 computer you can play w/ shift points, program the gear ratio, etc....
 
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Greetings Joe, from a NWFA member here in Oregon.
My personal opinion (I also had a heavy, armored jf80, with 35’s and 4.56 gears) is that your eventual tire size should dictate your choice.
If you think 35’s, I wouldn’t personally go higher than 4.88, specially considering your description as an over lander.
If 37’s, then *maybe* 5.29, but they still might get tiring if you’re loading up the highway miles.
Just my opinion...
 

Road Apple

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With 5.29’s, the pinion gear has 1 less tooth and is a bit smaller. There are plenty of people running 5.29’s without any problems.

Another option is to regear the transfer case with 10% high range underdrive and 25% low range gear reduction. The 10% high range give the same gearing as 4.56’s in the diffs, which is good for 35’s.

Since I’m running 37’s, I went a step further with 4.88’s in the diffs and regeared the t-case, for a bit lower gearing, but my truck is 80% off road.
 
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I run 5.29s and 35's and I see about 2800-3k rpm on the highway at 70 and 75 mph respectively. It's definitely a bit louder since the engine's spinning pretty fast. Also, you have to make sure your drive line is dialed in, since the driveshafts are spinning faster. Any problems are exacerbated by the higher rpm. That being said, it's definitely doable, and if you do end up getting 37s, you'd be even closer to ideal.

If I was starting over, I'd definitely be looking at those transfer case gears pretty hard. Maybe not enough reduction for 37's, but seems like there are some advantages over regearing the diffs.
 

baldilocks

Battle Ground, WA
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5.29=weaker pinion due to only one tooth being engaged at a time. 4.88 is the mathematically correct ratio for 37’s and 4.56 for 35’s meaning speedo and odometer will be accurate. If you want more torque to the ground for all that over landing you are planning, a set of 10% under drive gears for the transfer case will give you that and keep you away from the 5.29 pinion. And while the case is open you can install the 3.12 low range gear set.

I run 4:88 and 37’s. Acceleration is noticeable slower than with 35’s but, as said before, the Speedo is dead on and I can do 55mph in second gear with the tach up where the engine is making power all day long if necessary.
 
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I just did 4:88 on 315 tires and I would not have wanted to go any more, we do a bit of highway driving and at 65-70mpr its about as high as I would like to see the rpms. I did do underdrive low gears and that got me the low gear grunt I was looking for.
 

MoJ

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4.88 with 315’s is just below 3k rpms at 80 mph. It’s also geared slightly more aggressive/lower than stock. Combined with a yellow box speedo correction it’s a very drive able combo. I don’t have any experience with 5.29 but also have no desire to try it.
 
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I’ve had 5.29 nitros for 10 years on 37s, Toyota engines are meant to rev. I have no issues doing 80 in the mtns or pulling passes at 4krpm hasn’t hurt the engine one bit. You can pop the front gears in these trucks on stock gears with the front locked and going up stuff in reverse. Learn the weakness of the drive train and you’ll be fine.
on another note I’d skip the 5.3 and go bigger. When I was looking at Ls swaps each person I talked to told me don’t bother with 5.3 go5.7 or the 6.
 

80t0ylc

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My earlier post where I mentioned that I've heard that the 5.29 was weaker than the 4.88 was explained by @baldilocks & @Road Apple and now remember why - thanks guys for the info! I also forgot to mention the tire size I was running with my choice of 5.29's. It's 315/75/16. When regearing, I went with Zuk at Toyota Gear Installs, I initially chose 4.88. Zuk suggested 5.29's if I was going to be towing. I'm glad I did and I'll just have to keep it in mind about the weaker pinion when stabbing the skinny pedal, when I have a choice.:hmm:
 

80t0ylc

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I’ve had 5.29 nitros for 10 years on 37s, Toyota engines are meant to rev. I have no issues doing 80 in the mtns or pulling passes at 4krpm hasn’t hurt the engine one bit. You can pop the front gears in these trucks on stock gears with the front locked and going up stuff in reverse. Learn the weakness of the drive train and you’ll be fine..........................

You bring up a good point. The hypoid gears in our diffs have a weak side and a strong side. The weak side is used in reverse, so if you're tugging someone or something and you have the choice - make sure you're "applying the coal" in 'D" not "R"! In the attached image (left side diagram), you can see the "drive" side and the "coast" side. In drive, power is applied on the "drive" side. And in reverse it's on the coast side. When power is applied on the "drive" side, the ring and pinion gears basically transfer power through meshing vertical surfaces. But while in reverse, power applied on the angled "coast" side, under extreme torque stress the pinion could slip up the slope of the "coast" side and gear damage would result. One can see that the 5.29's, with fewer pinion teeth engaged in the ring gear are more susceptible to gear damage in high stress situations.

GearInfo.GIF
 

Joe Link

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I'm still conflicted, but I'm leaning toward 4.88's. If I think I need to go lower I can re-gear the transfer case and it'll be the same (or close) as having 5.29's in high, right?
 
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I'm still conflicted, but I'm leaning toward 4.88's. If I think I need to go lower I can re-gear the transfer case and it'll be the same (or close) as having 5.29's in high, right?
Yes, as long as you're not paranoid about the t-case gears not meshing quite right.
 
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- Currently running 33" BFG KO2's with around 60% tread left. If I can suffer through it I'd like to run them until they wear out, but this is a dumb reason to go with one ratio over another. Once these wear out I'm planning on going with either 35's or 37's (90% sure it'll be 37's, you only live once).

So, if you don't do a lot of hard core rock crawling, why do you need 35s or 37s? I've done some of the more hardcore stuff around here, Imogene Pass and Engineer Pass, with 255/85/16 KM3s on an IFS Tacoma. If you're already heavy, then a 35 or 37 will make it even heavier and slower even with the regear.

What rock crawling have you not been able to do with your current 33s?
 

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