No More Lugging — Re-Gear to 4.88’s and Front ARB Locker
No More Lugging — Re-Gear to 4.88’s and Front ARB Locker
December 6, 2017.
Over the last 17 years, the truck has been amazing. Truly a joy every time I get in it, work on it, or even just get all googly-eyed looking at it.
But, as we’ve started bigger and longer adventures, and turned it into an adventure truck as much as an around-town-mobile, the truck has slowly gotten to a point where it was time to do something about the drive train.
Big Tires = Big Problem
…and by slowly, I mean it was about like this:
And that cliff, right there at the edge, was the installation of bigger tires. See, before that, even with all the extra weight from bumpers and sliders and bed racks and CVTs, the gearing was OK — so I could get rolling easily in first gear, climb up a rocky road without going into 4L, and my gas mileage was still pretty reasonable.
But those tires screwed all that up. I was lugging as I’d start from a stop light, and simple hills would require downshifting to third gear, from fifth. And my gas mileage dropped from ~19 to 14 mpg.
Such is the slippery slope of vehicle modifications, I guess. To more easily go on the adventures, you need the bigger tires, so those weren’t going away. Instead, the discussion of what gears to get, and how to get them began.
There were really two choices I had to make:
- What gear ratio to go to?
- How to get those new gears installed on the truck.
Choice 1: Gear Ratio
From the factory, the truck came with a 4.10 gear ratio. Of course putting on larger tires meant that the gears were pushing the truck further down the road (since one rotation of the wheel is now a larger circumference), and so at any given speed, my RPMs were lower by about 6–7%.
To bring those RPMs back up into the power zone (between 2500–3000 RPM on a 1st Gen, V6 Tacoma), I’d need to change the gearing. My choices: 4.56, 4.88, or 5.29 ratios.
5.29’s were out — that would be too much gearing for my 33" tires, especially since the truck is still my primary vehicle. Driving around in town would feel like being in 4L, and I didn’t want that.
4.56 vs. 4.88 was a tougher decision. For “around-town,” 4.56 might be better — it’d get me back to (essentially) stock gearing, but when the truck was loaded for adventure, it might still require downshifting into 4th on hill climbs, and there might be places where I’d have to go into 4L that I may not otherwise. For adventuring, 4.88’s would provide that lower gearing and power, at the expense of some “around-town” efficiency of 4.56’s. In the end, I decided that the direction the truck is going is towards adventure — and so 4.88’s would be the best fit.
Along with that decision, everyone I talked to recommended that I get a front locker as well. I already had the OEM rear locker, and putting an ARB air locker in the front at the same time would be the obvious, economical choice. And of course, it wasn’t their money! Lucky for me, I already have an ARB compressor, so much of the work was already done.
Choice 2: How to Install?
In the early days of the truck, the only real work it needed was “regular maintenance” — which for me meant an annual oil change since I drove it so infrequently. With a coupon from the dealer, it made little sense to do any of this myself. But now, I try to do most of the modifications and maintenance myself — both so I can learn more about the truck and so that should something break on the trail, I have a better sense of how to fix it or what it “should” look like.
So, I initially thought I’d partially install the new gears and locker myself. Really, I had several options:
- Order some gears (perhaps through a group buy) and install them myself.
- Order some new, assembled differentials with the gears already installed, and replace the diffs myself.
- Pay a shop to install new gears in my existing differentials.
As I researched thought about it more however, I very quickly realized that #1 was way out of my league. Being one of the more finicky items on the truck, I knew that I didn’t have the tools or the know-how to do the actual gear install myself. I also talked to some guys who did have the know-how and did install their own gears, only to hear them say that they wouldn’t do it again — they’d pay someone.
Well, hearing that also made me question #2. There are really two reputable places to get gears — ECGS (East Coast Gear Supply) and Zuk in Arizona (Toyota Gear Installs). I liked the Zuk was using Nitro gears, and a quick email exchange with him netted a lot that I liked hearing — he was happy to do both the gears and the locker, and he’d do it for a totally reasonable price. But, there was a problem — he didn’t do the actual install on the truck, so I couldn’t drive it down for a couple days and “be done.” Instead, I’d have to take out my diffs, ship them down, get them rebuilt, and then wait for them to get shipped back so I could reinstall them.
That would mean two weeks of “truck on jack stands” — longer than I wanted (or could really pull off given the lack of a shop). I was also unsure that the front diff removal/install was in my wheelhouse — at least alone.
So that left option #3. It was the most expensive option, but it was also the one with the highest success rate, and the shortest timeframe. I had a great recommendation from Mike (@Digiratus) for a semi-local shop — JT’s Parts and Accessories — and so I gave them a call.
Communication was great with Carl and we worked out a mutually agreeable time and price — I’d bring my truck in when the shop opened on December 6, and I’d drive it home when they were done the evening of December 7. Not too bad, especially since it meant a night in Leavenworth with @mrs.turbodb while we waited. Win win.
Install Day
I was up early on install day, leaving Seattle by 4:15 am. With a fuel stop, that got me to JT’s Parts & Accessories just before they opened at 7:00am — perfect timing. I headed in to say hello.
A couple guys were there and let me know that Jared and Chris, who would be doing the work would get started around 8:00 am or so. They suggested I take the short walk into town and grab some breakfast, and then that I was welcome to hang out and take pictures of the work once it got started. Sweet.
At 8:00 sharp, Chris and Jared arrived, and it was time to get started. Into the shop we went, and as they got the truck up onto the lift, I was immediately jealous. I need a shop like this.
Not losing any time, the wheels came off first, and then the truck went higher.
Next, out came the rear diff oil (apparently “weird” on my truck because the drain plug is on the wrong side), as well as the rear axles. Watching Jared work, it was clear to me within the first 15 minutes that I’d made the right call — while I could have wrestled these things myself (though much harder without a lift), it was great watching an expert do it the first time.
It’s not every day you see your drive shaft up between the gas tank and exhaust…
As the rear diff was disassembled and drained, Chris got to work opening the new parts to be installed, and doing the final machining on a solid spacer for the rear diff. Even though these guys do this all the time, it was nice to see Chris excited to open everything in the same way I’d have been — “Oooo, a new ARB!”
In the end, the newly installed parts were a Nitro 4.88 front and rear gear package (with Nitro rear ring & pinion, Nitro front Master Install Kit, Nitro rear ring & pinion, Nitro rear Master Install Kit, Front pinion pre-load solid spacer, Rear pinion pre-load solid spacer, and Front Yoke) and an ARB 7.5" RD90 air locker for the front diff.
Little did I know what the rest of the day would hold — it was amazing! You can read about the rest in New Gears for AdventureTaco at adventuretaco.com.
Originally published at adventuretaco.com.
