Regearing 6MT to 5.29 Revolution Gears

Long post alert - put on your reading glasses. I wanted to share my experiences three weeks after regearing my truck to 5.29. I am at about 1800 miles with no leaks, gear noises, or issues in general.


Parts Used:

• Revolution 5.29 gears F/R
• Revolution Minimum Install Kits F/R
• OEM E-Locker Connector - 82824-0K060
• ECGS Diff Bushing
• ECGS Crush Sleeve Eliminators

OEM carrier/side bearings:

• Front L&R - 90366-53004 (so 2 total)
• Rear Left (large) - 90366-T0068
• Rear Right (small) - 90366-T0071

OEM Pinion Bearings:

• Front Outer - 90366-30067
• Front Inner - 90366-35087
• Rear Outer - 90366-T0062
• Rear Inner - 90366-T0065

OEM Seals (pinion and left front CV):

• Front Left CV Seal - 90311-47027
• Front Pinion Seal- 90311-41015
• Rear Pinion Seal - 90311-T0065

Fluids and Pumps:

• Torco RGO Mineral/Conventional 85W-140 GL5/6 (12 Liters - Used 11 for initial fill and the 500 mile fluid change)
• MityVac MVA6851 Syringe-style fluid pump

Truck Stats:

2021 TRD Off-Road
6-Speed Manual
Factory 4.30 Ratio
265/65R17 (30.6") Toyo ATIII (Stock TRD Sport size)


Why I regeared

When I got my Tacoma, I knew I wanted to regear it. I've owned a Jeep and several trucks over the years now and I've regeared more of them than not. The stock 4.30 gears did work pretty well, and I liked how they cruised the highway at 2450-2850 rpm (70-80), but I didn't really like the low end performance from 1st-5th gears.

I scheduled for my gear install somewhere back around mid-June 2022. I utilized Chris from Triple C Chop Shop (@Texoma) down in Lago Vista, TX. A lot of people have him do gears so he was booked out a while. This gave me a lot of time to think and go back and forth on my decisions. At first, I decided I was going to stick to the stock size tire forever, which would be the 30.6" 265/65R17s I'm running. That is a TRD Sport tire size, but is equivalent to the 265/70R16 that came on my truck originally and the other TRD Pros and Off-Roads. The plan to accomodate that tire size was to regear to 4.88, which is what I originally purchased. The idea here was I would cruise 70 mph at around 2800 rpm, which would be a significant boost to performance without being over the top on cruising rpm.

The downside to 4.88 is that it's really only a 13.5% gear reduction. Not that that is necessarily bad, but it's not a huge change when you're spending roughly $3K to gear swap. Many folks want to get the best bang for their buck, meaning the most change they can get without going over the top. 4.30 to 5.29 is a 23% change, which helps support the bang for buck goal.

I started thinking about possibly running larger tires, like 265/70R17 (31.6"), 235/80R17 (31.8"), or 255/75R17 (32.05"). I've never really wanted "large" tires, but none of these are that large either. They are a slight improvement in looks and offroad clearance, while not adversely affecting handling or needing any suspension modifications. I started running the numbers on these tires and knew that larger tires, combined with the small gear reduction of 4.88 gearing, just wouldn't be worth the money to me. As such, I ordered 5.29 gears as well (I had already ordered 4.88 previously). The plan was now the larger tires and 5.29.

I went back and forth in my plans, day by day, changing my mind. Once I finally got close to my regear day, I finally said screw it, going with 5.29s, tire size be damned. The truth is that no matter what tire I run, I can live with the 5.29s. If that means stock tires for a while, that's fine, I'll just drive a bit slower on the highway and enjoy the increased performance in all other conditions. I did end up going with 5.29s, with which I am on stock tires for the time being.

The thing drives like a beast! 1st gear is pretty short, but I can still wind it out to 25 mph or so before I hit redline. The middle gears (2-5) are all MUCH improved, there's just a lot more get up and go when I want it. 6th is decently low....it cruises 70 mph at about 3000 rpm, and addtional 5 mph increments bring the rpm up by about 200 each. It is not as bad as it sounds, the motor really just sings there and moves down the road effortlessly.


The Install

Not a lot to say here, mostly just wanted to share the notes and pictures from the install. I will say Toyota diffs need a lot of tools to get the job done easily. Chris has fabricated himself up a few nice helper tools that hold the diff or allow him to take measurements to get the job done right. Essentially it's the same gear job as any other diff as far as backlash, pinion depth, pattern, and pinion bearing preload go, but how you go about measuring and securing the diff so you can work on it is a different story than other vehicles.

Chris's Notes from Install:



Front Diff Drive Side Pattern:



Front Diff Coast Side Pattern:



Rear Diff Drive Side Pattern:



Rear Diff Coast Side Pattern:




Install Issues

Even with Revolution, there was some heartache. In the middle of the job, we found out the hard way that they sent the wrong pinion nut. That is disappointing because you're not supposed to reuse pinion nuts. It's not the end of the world, my old nut wasn't that old and it was still in fine shape, but paying $3k for this, you want it to be right. Neither I nor the gear installer had a spare nut, so we went on our way reusing the old, only choice we had.

The Revolution shim kit for the rear also did not give us enough of or the correct size pinion shims. Chris ended up having to dig into his shim collection to find something that would work. Ultimately not the end of the world, but if he wasn't prepared, we would have been a bit screwed.

Lastly, ECGS caused a hiccup as well. I ordered crush sleeve eliminators for both front and rear, and they sent me the wrong one for the rear. We figured that out as well mid-install. So, I did not get the rear crush sleeve eliminator installed like I wanted. Not the end of the world either, but I paid the money and didn't get what I paid for. Mistakes happen, but to find them mid install and having to improvise and settle for things I wanted to avoid, kind of sucks.

I guess, in the future, I would try to visually inspect every part and make sure it's all correct. I should have verified the pinion nut, the crush sleeve eliminator I would have had trouble with. I received a crush sleeve eliminator, but it was incorrect. That is not immediately apparent if you aren't personally familiar with the diff. I would have had to research and get pics of others to compare with. Oh well, hindsight is 20/20.

The Break-In and 500 Mile Fluid Change

As with most regears, break-in is something you need to do. Mostly driving easy for a few warm up cool down cycles, and then just driving normally with no spirited driving until roughly 500 miles. Obviously, the 500 mile is just a number, not super critical because 500 miles means a different amount of usage depending on the tire size and ring and pinion ratio you chose. For me with tiny tires, 500 miles is a lot more rotations of the gears than it would have been on larger tires. Anyways, 500 miles is a safe number that basically proves the gears are running fine. Put it into 4WD some to break in the front as well.

Another reason for the break-in is to get the coating off of the gears so that they are finally meshing on their normal surface. This is easily seen on a used set of gears where you see the shiny metal showing the pattern where the gears have been meshing. The break-in process and initial use of the gears creates that visible pattern.

I was halfway done with the break-in by the time I got home...roughly 220 miles. During the ride home, I varied my speed, I did lots of 5-10 mile stretches at 60, 65, or 70 miles per hour. I stopped every 50 miles for 30 minutes. It was a long ride home to end a really long day. I got home at 1AM. For the following 4 days until I reached 500 miles, I drove easy although I did take it up to 80 mph a few times just to see how it did. No issues to report.

At 500 miles, I drained both diffs and refilled with the Torco RGO 85W-140 conventional mentioned above in the parts list. I like this fluid because it comes highly recommended by axle builders and is known to be thick so it doesn't shear down and provides solid protection. I'm sure most anything would be fine but I like this stuff as a known good choice.

I highly recommend getting a

$26 Mityvac MVA6851 7oz Fluid Evacuator Extractor and Dispensing Syringe, Lightweight, Easy to Clean, 7-1/2" Flexible Tube, Non-drip Cap, for Master Cylinders, Transaxles, Power Steering and Coolant

syringe pump for faster filling. There is one caveat....cold thicker fluid does not play nicely with the syringe pump. Putting the bottles in front of a space heater for 30 minutes or so warms them up enough to get the job done. If it's sunny out, you won't have a problem and if you set the bottles in the sun, even less of a problem. Overall this is a much less messy way to fill the diffs compared to using a bottle pump that requires you to pump 300 times to get through 4.5 quarts. I also like to drop the spare tire so I can sit under the truck for filling.

I needed 12L worth of bottles to do both diffs twice. I will change every 25K here on out.


Gas Mileage

My gas mileage was never good on stock gears. I drive with a lead foot and cruising the highway at 75-80 isn't conducive to achieving good mpg no matter what rpm you're taching. I bought the truck knowing that and don't really care. The gears lowered my mpg a bit. My all-time average mpg on the truck is 15.8. Obviously not much time has gone by for that to drop from the gears yet. However, my tanks since I did the swap have been 17.9, 14.7, and 16.1. This is 1200 miles worth of road trip back home, putting around town, and commuting to work.

If you take my previous gears and my current setup and set them both to 70 or 75 mph, in the exact same wind/road conditions, I would expect the stock gears to make about 1 more mpg. However, that's not always the case and it's just not that simple to say "more rpm = more mpg". Sometimes the extra rpm works to help you with volumetric efficiency from the engine which can be more efficient despite spinning higher rpm. Really, all this just means that while my mpg may be worse, it isn't 23% worse, and I'd much rather the performance for the mpg tradeoff because my mpg was never good to begin with.

If I had to sum it up quickly, I would say lifetime mpg was 15.8 before, and will be around 15.0 now.


Noise

One of the biggest conversation starters for regears is the added noise they bring. I seriously considered buying an assembled 3rd member rear and a front clamshell from East Coast Gear Supply. They would be already assembled and ready to just bolt in, which would have been fantastic and I could have been done 6 months ago. The reason I didn't do that, is because of all the noise complaints.

Revolution ONLY uses gears from the Circle K foundry in South Korea, and they have a good track record. Jeep guys have great results with them, so I chose to use those and forego the ECGS assembled diffs route. This isn't to say that Revolution/Circle K gears are better than Yukon or Nitro, just that I always know what I'm getting when I order from there. Yukon switched to Chinese manufacturing over the last few years and many gears, if not all, come from China. That is not necessarily a problem, but I have seen several gear setters express disappointment at the more recent Yukon R&P sets. So, I chose Revolution.

I have zero noise complaints from the gears themselves. Chris set them up well and they make no noise other than typical very slight coasting whine. Definitely no worse than stock was. I am happy with the Revolution choice for noise.

I did, however achieve more noise in one way…the manual transmission. Ever since the swap, around 70-80 mph in 6th gear, there is a slight ringing noise. The noise goes away when I put it in 4th gear which is when the transmission gears are bypassed and the input shaft is simply locked to the output. As soon as I'm in 5th or 6th, the noise is back. It's not the end of the world and nothing is wrong, it's just the transmission is spinning quickly from the regear. It is what it is. Radio drowns it out and I'm not concerned about it being a problem or anything. When I eventually step up my tires a bit, that will help.


Final Thoughts

I don't regret the gear swap at all. The performance is awesome, mpg is not bad, and the truck's performance suits me better now than it did before. The plan is to step up the tires when these tires run down, so in a year or so. I want to do some Colorado or Tennessee trails in the summer, if that happens I'll probably step up my tires before the trip. We'll see. Overall I really like the gear swap even on stock tires, I don't at all wish I went to 4.88. Obviously, many people will have different opinions, but I am of the opinion that if you're not paying attention to the rpm on the tach, then it's easy to forget about revs and just enjoy the new driving experience.

Lastly, just sharing a "flex" shot that Triple C does with each customer. Normally I'm not into these, but Chris does have a cool house on a hill with a steep driveway which naturally creates a neat shot, especially at sunset.

 

Great info!

 

Nice info!! I’m running 4.88’s with a tune 255’s full armor etc .. 70 mph 2k rpm’s

 

Also running Revolution Gears great company to deal with

 

I like them because if you follow the setup specs and set them up accordingly, they seem to always be quiet. I've been in the Jeep world a lot longer than the Toyota world and over there, they are the best option so that's why I went with them this time.

The only problem is, their install kits were a bit subpar. Their install kits are a lot better on the Jeep applications.

 

Thanks for the detailed write up! I don't know if I'll ever re-gear, but it was a fun read.
How does it feel starting in 2nd gear? Can you skip first entirely or is 2nd still too tall?

 

It is still quite tall....can do it significantly better than before, but it still bogs down bad. A lot of people think a drastic gear ratio change like this will shift all the transmission gears 1 gear over, but not really. 6th is about where 5th was before and same for new 5th vs old 4th, but otherwise all of the other gears are still not as low as the old one before them was.

As such, 2nd is still tall. I use 1st all the time. If I did the Hilux transmission, then 2nd might finally be good enough to start in full time. At that point, 1st is annoyingly low for using all the time, which is why I'm hesitant to swap to that transmission (plus the cost factor and the fact that you have to immediately tear the entire thing down to swap the input shaft to a usable one for our engine). Overall my situation is pretty good on the stock trans and 5.29s, reverse could be lower but it's fully livable at this point.

I'm kind of leaning 255/75s, supercharger, and stock trans for long term.

 

Appreciate the write up. Nice to know reverse gets a bit better. 5.29s are definitely on the short list - With the Premier West Gear groupbuy going on I am definitely tempted. I believe Yukon is the only option for gears though.

 

I don't think you'll regret it. Yukon will be fine. All of them are fine, seems like Nitro is the noisiest. I think a good portion of it has to do with setup and luck. Mine were setup very well, and are quiet. I've seen others say Revolution are noisy and quiet. The only variable really comes down to setup at that point. I also default to the thicker fluid simply to help mask the noise. I've only seen one person say that thinner fluid quieted their diff.

Good luck!

 

OP, did you install a speedo calibration unit to get more accurate mpg calculations?

 

No need, gears don’t affect it. Only tire size affects it. When I get larger tires I will get a calibrator.

 

My bad, you're right. I forgot you stayed with stock tire size.

That thing must be a tractor in 1st gear.

 

it is pretty torquey in 1st. 2/4LOW are.....low

 

I have a 6M '17 OR and went with Yukon 4:88's and 255/85R16 (33.1") BFG KM3's.

Also, a Rough Country speed calibration unit.

This combo is very comfortable in most situations I drive. Towing, highway, city, trail, desert, etc.

Having the max torque higher in the rpm range limits my "crawling" some, but I don't do those kinds of trails much. If down the road I find myself wanting to do real crawling, a modded Tundra R/P steering, a Marlin TacoBox, and RCV axles might be in the build.

Sounds like your rig could easily take some body armor and not flinch, all while climbing a tree.

 

Yeah, you ended up with more of a stock type of setup. Nothing wrong with that if you like it. I wanted a bit more than stock and I really don't go crazy with my plans, no 33's or armor or anything. I really just like a spirited-driving daily driver. I like to cruise around 2800 rpm at 70, and my future 255/75/17 tires will accomplish that on these gears.

Really though, even the 5.29s aren't as drastic as they sound. It seems pretty crazy but other than the 3000-3200 highway rpm, people could totally drive this and believe it was just a good performing stock vehicle. It is not at all like a wheeling buggy or anything like that. My driving style is winding out the gears much of the time. Highway merges, I'm pretty much never shifting below 5000 rpm. The regear helps with that a lot because it winds out the gears faster which keeps me in the high end like I like to be for accelerating.

The only thing I wish was better really was 2nd gear. 2nd gear still has no balls at all until I'm at 10 mph or more. It is much improved over stock but it could still be so much better.

 

Couldn’t you have just shifted later and accomplished basically the same thing? The only real improvement I can imagine is a slightly improved ability to keep the engine in a tight power band, but I don’t race my truck often so I don’t much worry about it.

 

eh...not really. I already did shift late on stock gears. The whole experience of all gears is just significantly better across the board. It's also difficult to envision the affect until you see it firsthand after the swap is done. Tons and tons of speculation out there about gears and what it will be like after it's done and 95% of it is wrong.

I don't race my truck, I just like better performance.

 

I don’t need to speculate that much. I have tons of experience tuning gears on bicycles, shifting into 4lo on the truck, and driving vehicles with different gear ratios. They don’t increase performance per se, but they can improve drivability/rideability by giving you proper gear ratios for the type of speeds you are planing to encounter. I think much of it comes down to personal preference.

 

When I shift into 4lo, I don’t think my truck’s performance has increased, but I definitely appreciate having more useful gears to play with under 30 mph. I guess maybe it depends on the definition of performance.

 

The crush sleeve eliminator is a solid spacer, it would look like 3/4" long piece of pipe with thick walls. Thats probably the easiest way to describe. First think I did when I removed the pinion was slide the spacer on to see if it fit.

The crush sleeve looks similar but has a rib in the middle of it designed to be crushed to size as your torque it to spec