2005 4x4 regear questions

Hey all. I would like to start by saying I have a stock gearing in my 2005 AC V8 4x4 with no mechanical LSD

(this is due to my uncommon hydro-assist brake system that provides traction control and an “auto LSD” that instead of locking the wheels just applies the brakes to the side that is spinning. This did not come with a way to disable the system but I will wire up an “off switch” for it soon. It is disabled in 4x4.)

Lacking a mechanical LSD I feel limited off-road and I would like to install a selectable locker rather than an LSD, so I don’t run the risk of accidentally engaging the traction control brakes with the LSD engaged as that could cause some drivability issues/damage. When I install the rear locker it would be a good time to re-gear the truck.

Being a weird unicorn tundra I am not 100% on its current gearing. From what I have found on most other 05 v8 4x4 tundras it should be a 3.91:1 ratio. My current tire diameter is 33.4” and using gear calculators online I should need 4.23:1 gears to get back to a stock ratio. The closest options I have found are 4.10 and 4.30. Leaning towards the 4.30 over the 4.10 or more popular 4.56+ lower gears as I do travel long distances @70-80mph (true speed) in this truck and do not tow. For any off-road applications I also have 4Low. I have seen in other tundra forums that the T-100 came with a 4.30 that will fit into (some variation) of first gen tundras but can’t confirm if it will work for mine.

I am not knowledgeable about gearing at all, thus I seek your expert advice or non-expert first hand knowledge. My goals are to…

1. Regain close to stock gear ratios with my new tires.
2. Find a selectable locker compatible with these new gears.
3. Keep total cost low, but not at the expense of reliability. (Not looking to drop $10k in indestructible rock crawling parts)
4. Get a parts list of everything I would need to to purchase to achieve this as I just don’t know enough yet (front and rear ring and pinion gears, something about a 3rd member, and a comparable locker?)

Thanks for your opinions on companies/quality and tips about interchangeable parts and compatibility to keep the budget reasonable. Gotta pay to play, but I’m playing in city league softball - not the MLB.

 

1. Are you going to be carrying any additional weight in the bed full time? I would go for 4.56s with that size honestly. You'll be unimpressed with 4.10s with that tire size. 4LO with 4.10s and 33s is okay, but not low enough IMO
2. Eaton/ Harrop E-locker is your best option for a select-able locker. ARB air lockers are another option, but they come with their own issues and require an air compressor from the get go. (My gear installer will no longer install air lockers)
3. You can probably get the job done right for sub-$5k.
4. See below.

Front:
- 7.5" reverse IFS Clamshell ring & pinion gears in your ratio
- 7.5" reverse IFS master install kit (these are the bearings, shims, and internals the gear installer uses)
- ECGS Bushing to delete OEM driver's side needle bearing
- Solid Spacer to replace crush sleeve (optional, but recommended)
- Left and right axle seals from Toytota
- Gear Oil

Rear:
- 8.4" ring & pinion gears in your ratio
- Locker unit (e-locker or air)
- 8.4" master install kit
- 8.4" diff solid spacer (optional, but recommended)
- RTV/ paper diff gasket from Toyota
- Gear oil

The third member is slang for the full rear differential, usually gears and everything. The third member is remove-able from your axle housing and axle shafts.

Are you looking to have someone take out all the parts from your truck, install the gears and lockers in the differentials, then install everything back in the truck for you? Or are you looking to have differentials built and you throw them in the truck and do part of the work?

If you're doing part of the work yourself, you can order built units from ECGS (East Coast Gear Supply) and put them in your truck. ECGS ships you completely built differentials, then you remove your stock ones and mail them back to ECGS.

If you're not doing any of your own work, you can find a shop to remove your current differentials and add the ECGS units for you.

If you're doing part of your own work and finding an installer to set up and built the differentials themselves, you'll have two options:

• Option 1 requires multiple days of downtime for your truck. You remove the front and rear differentials from the truck and take them into the installer. The installer removes your original ring and pinion and other internals and installs all the new parts.
• Option 2 requires no downtime for your truck. You find stock front and differentials from another someone is selling or pull them from a junkyard. You take these differentials to an installer, they remove the internals and install the new parts. When the installer is done, they are built differentials. You remove your stock differentials yourself and install the built differentials in your truck, then you can sell your stock differentials for someone else to repeat this process (this is what I did).

Also look into REM polishing for your ring and pinion gear sets. If you do REM polishing, there is no break-in procedure for the differentials. You can order REM-polished gears from Revolution Gear, or find a shop that offers REM polishing.

http://gearinstalls.com/ is my gear installer's website, lots of detailed information on there. If you're able to do option 1 or 2 and travel down to AZ, I highly recommend him.

 

This is exactly what I was looking for thank you. I knew there were plenty pieces I needed but didn’t yet know about. I like the optional parts as well. I tend to research and slowly gather parts for months before pulling the trigger and installing. Getting some junkyard parts, sending it off for rebuild, and then installing at home is likely the route I will go.

I don’t often carry a lot of weight in the bed and my only hang up on 4.56 gears is that I drive 90% freeway miles on 8-10hour trips @70mph and then crawl around on forest service mountain roads the other 10%. I had a jeep with 35” tires that was geared really low and after just one hunting trip (10 hr drive) with the high rpm and bad mpg I decided to buy a Tundra instead. The 4.30 would still be geared a little lower (0.07) than stock, and on paper I like it more. But it’s hard to argue with people who have first hand experience. What could I expect with the 4.56 gears? We also have different transmissions and I wonder how the extra gear in mine might affect the overall ratio.

Thanks again for the detailed response and recommendations

 

A super budget option is grabbing 4.10 diffs out of an 04 DC or any year 1st gen sequoia.


With the larger tires though, 4.56 would be the jam.

 

That’s kind of the decision I need to make.

• Budget option - 4.10’s, less work, low acceleration but maybe better highway mpg, could possibly get it done under $2k.
  
• Near stock ratio- 4.30’s, just as much work and as expensive as 4.56 install, decent mpg
• Performance option- 4.56’s, accelerate faster, tow more, worse MPG, maybe extra engine wear at higher rpm on long trips? Be cooler than the first 2 options.

For the budget option I would guess that by installing a rear locker it would also be as expensive as the other two without the cost of gears themselves. Are we sure the 04 and earlier parts/gears are all compatible? No surprises on install day? Any truth to there being a compatible T100 4.30 option?

 

For differential cores:

Front
00-06 Tundra
01-07 Sequoia
96-02 4Runner
95.5-04 Tacoma

As noted, 2004 DCs and some Sequoias will have stock 4.10s. (Not sure if all 4.10 diffs are mechanical LSD, but mine was)

Rear:
00-06 Tundra
01-07 Sequoia
92-98 T100 w/o factory 3.31 gears
95.5-15 Tacoma w/o factory e-locker

With my 4.88s and 33's, I can comfortably do 70-80mph for long freeway stretches. My third is the same as your fourth gear, and our O/D are only off by 1.5%. You'll probably get some responses from folks that actually have 4.56s and a five speed. @455h0le_dachshund

Getting up to speed a little quicker, definitely less pedal effort on the forest service mountain roads.

 

2000-2003 Tundra
3.91 - V8, 4x4, auto trans
3.92 - V8, 4x2, auto trans
4.08 - V6, 4x2, auto trans or manual trans
4.10 - V6, 4x4, manual trans
4.30 - V6, 4x4, auto trans

2004, Regular Cab or Access Cab
3.91 - V8, 4x4, auto trans
3.92 - V8, 4x2, auto trans
4.08 - V6, 4x2, auto trans or manual trans
4.10 - V6, 4x4, manual trans
4.30 - V6, 4x4, auto trans

2004, Double Cab
4.08 - V8, 4x2, auto trans
4.10 - V8, 4x4, auto trans

2005-2006
3.77 - V6, 4x2, auto trans
3.91 - V8, 4x4, auto trans
3.92 - V8, 4x2, auto trans
4.08 - V6, 4x2, manual trans

I believe the manual trans T100's and first gen Tacomas and 3rd gen 4runners came with 4.30 gears, but must NOT have TRD e-locker, or the diff will be different.
But I think the T100 front diff is different from ours. So I doubt their front gearing would work for you.


I have 4.56 gears and Eaton rear e-locker in my 06 4wd, with 295/75r16 tires (33.4x11.6).
I wanted 4.30 gears, for the fuel economy as well, but at the time no one had them in stock. They seem to be harder and harder to find new. Finding em in a junkyard probably won't be any easier. But who knows, you might get lucky.

Anyways, I love my 4.56's. I get between 12-15mpg highway, depending on how flat the road is and my speed.
Sometimes I think about what it would be like if I had gone overkill will 4.88's, but I'm sure I would get like 10mpg.

 

The Sequoia I harvested a third with 4.10 gears for my 03 2wd was open diff. Not sure what year it was though.

 

I'm not 100% certain but I think the earlier tacoma/4runner/t100 diffs may use a different R&P. Less bolts for the ring gear and smaller diameter pinion spline for the flange.

 

First i want to address the elephant in the room…you said “I drive 90% freeway miles on 8-10hour trips @70mph and then crawl around on forest service mountain roads the other 10%.” And that you also “drive long distances at 70~80mph.” You also said that you’re concerned about fuel economy with the 4.56 gears. You already know that the 33.6” tall tires aren’t doing you any favors in the mpg department.

All of us here love our oversized tires (including me), but if i were pounding as many miles as you on the pavement, the first thing i would do is install smaller tires and completely forget about a gear ratio swap. There’s not too many forest roads in the US that can’t be traversed with 29~30” tall tires.

Now let’s say you were to scoff at all of what i just said and you still want to proceed with you plans…
4.30 gears will get you back to being close to equal with the 33.6” tire….BUT then you’ll definitely need to make up the additional weight of the tire mass themselves, which means you should go one gear ratio lower, which would put you right about a 4.56.

Having a 5 speedo transmission over the 4 speed won’t make much difference at your cruising speed. I don’t know what rhe final gear ratios are for the 4 and 5 speeds, but that additional 5th gear doesn’t give you a double overdrive. All it does is provide a closer ratio shifting in the transmission (which of course is a good thing).

I’m not trying to rip on you for pounding pavement miles on large tires, and i’m not judging either. But tires and gas ain’t cheap and you’d be burning both of them up.

ARB is probably the strongest locker out there. As to most reliable?…well the ARB can be very reliable IF the installer goes above and beyond to be careful when it comes to fitting the O rings. Also the included plastic air lines are another fail point. Swap it out with the braided stainless -03 PTFE (same hose for brake lines) and you won’t ever have hose leaks…like ever. I have ARBs in two different jeeps. If i ever install a locker in my tundra i plan to go ARB as well. The Eaton E locker will also work great as well. It’s a literal coin toss, but with $100 bills and not coins.

 

Thanks for your input, I appreciate it. The primary purpose of this truck for me is an adventure/hunting/camping vehicle. All of my favorite hunting locations are at high elevation on some nasty sharp rocked unmaintained roads in Idaho and Montana. When I was a hunting guide I shuttled clients into the wilderness over snow covered roads 10’+ deep. I did this with an 80’s 4Runner that had onboard air, arb lockers front and rear, 38” beadlock tires aired down to 5 psi, and a marlin crawler dual transfer case - all of that was completely necessary to be able to travel where we did. When I moved 8-10 hours from my favorite spots I bought a lifted jeep on 35”s locked front and rear but averaged around 8-10mpg and could not fit a whole dead elk inside without first completely processing it in the field. The next year I used my wife’s rav4 for better mpg but 8” of ground clearance and I overheated the transmission, shredded a P load Toyo at3 sidewall, ripped off the muffler, and nearly punctured the gas tank as I found once I was in the muffler shop paying for my sins haha. I decided the AC Tundra is a great truck for what I do as I can still get turned around on tight roads and in stock form has 11.2” of clearance - but it isn’t enough to avoid scraping on rocks in all places. In October during hunting season at 9,000ft it is not uncommon to receive 2’+ of snow overnight and the trip back out is very dangerous. The skinny E load 33.6x10” tires I have are a compromise between mpg and ground clearance/rock puncture protection. I am trying to get the tundra to a happy medium between the fully off road capable rigs and my wife’s on road efficiency. It’s not easy to find the perfect solutions because you can’t improve one aspect without sacrificing another. I have tired hard to keep it fuel efficient and am amazingly averaging 15-16mpg on the 33s now, but I would significantly reduce the amount of trips I make in a season if I went back to 8-10mpg. This is both because of the $$ for gas and because the nearest gas station is 90 miles or a 6.5 hour/180 mile round trip away if my tank is running low. I bring extra gas cans of course, but they add weight and slosh around violently/leak (expand with elevation change) on the trails. The tundra has to both make the highway trip there, and safely get me through difficult and isolated terrain.

I didn’t think about the 4.56 gearing helping with the added weight of the tires, and I should try to calculate what the actual difference in mileage/$ would be between the 4.30/4.56. A secondary gas tank would also help with my fear of running out of gas. Maybe I should just instal the locker (which I feel is very necessary from experience on these trails) and save the money I would spend on a re-gear for more hunting trips. That’s the whole point of the Tundra after all, more time in the mountains.

 

I had no idea you used to have a built wheeler. Since you had a Runner like that, then you know exactly what you’re after for your needs.

 

What size is your wheel? I didn't know there were 33.6x10's


Regear and locker at the same time, hands down.

 

Sorry, I couldn't remember the decimal place after the 10. Whatever tire website I looked at last said the Toyo M/T 255/85r16 was 33.6", but on the Toyo website they are listed as 33.5x10.2"

 

Taller gears don't mean better gas mileage necessarily.

My mileage went up going from 3.91's to 4.10's. The difference in higher rom is offset by lower engine load due to mechanical advantage. Sure the motor spins a couple hundred rpm faster, but at less throttle input.

With 33-35" tires I'd go 4.56.

 

You want 4.56. For sure this the current tire set up. Now if your looking to go on the cheap. Pull it yard , i used sequoia front, some 4- runner parts and a salvaged tundra that had 4.30. Add a grand for my ARB Rear locker ( i have had no issues). But i run a 31 or 32" tire and i really dont think any of us 14mm lbj guys should go bigger than a 32. Unless you enjoy wrenching ( which i did...10+ years ago) . Gents above are giving u good info. You would be upset w lack of change w a 4.10/30 swap for $ invested. 4.56 would change whole truck, and you will be under 3k rpm at 80mph. ( assuming u keep running 34" tires)

 

Well I didn’t make this post just so I could say that I don’t know anything and then disagree with those that do. Haha. The overwhelming support for 4.56 has convinced me that is the route to go. Even if it does end up costing me some mpg, it will put a bigger smile on my face by being a lot more spirited and fun to drive.

I will take a while to get everything together, could be a year or more before this actually happens. I will try to take detailed mileage logs so I can document the change that occurs. Going through many of HighwayLizards old mpg posts for inspiration. I’m thinking that some dirty deeds long tubes are in my future as they improve both mpg and power. Maybe a selectable Throttlebody coolant bypass depending on season, replace my spark plugs that are 65k miles old too. Then theres all sorts of more complex things that are interesting but I probably wouldn’t do like HwyLiz ram air and electric fans vs the clutch driven ones. The only other thing I could really think of to keep my 80mph cruising speed in lower RPM is a slightly taller 5th gear, but that would never realistically happen.

 

I've got the longtubes on my 06 with similar tiresize to you and 4.56. That's a nice combo. Don't forget to get your ECU tuned for the cherry on top for power and to disable the SAIS. Or you can get a Hewitt bypass to disable SAIS. You'll need one or the other for headers. I'd recommend the tune, two birds with one stone and all.
I did the bypass because at the time, there were no tuned for these trucks yet.

 

That’s good to know! I have gone the Hewitt route before and am familiar with it but this current truck is doing good so far. Does the tune provide block off plates? I can get some separately, seem to remember something about exhaust traveling backwards. But I believe the headers have no place for it to connect anyway. What tune/company do you recommend?

 

I didn't use block off plates. Headers should do the job.

My buddy did the tune for my 06 4wd. But he used VF Tuner. Lots of Toyota tundra out there using that software. If you can't find a tuner, you can always order a newly tuned ECU from Quantum Auto Tuning. But I've been waiting 2 months for my 03 2wd ECU.

 

How well does your light bar do being mounted way back on your shell?

 

It does really well, mounting it high really illuminates a larger area. I have pretty bright headlights and fog lights up front and by having the lightbar further back it keeps it from reflecting off the hood and blinding me. I bought it as a used Amazon item for like $40 4 years ago. It isn’t waterproof like it said, but it keeps working just fine and if a branch knocks it off it’s no huge loss. I didn’t want to mount it in the grill and I also didn’t want to mess with drilling and sealing in the cab or canopy so using the rails was pretty easy. It makes deer eyes so much easier to spot in farmland and has probably saved me from hitting one at least twice

 

Light bars before lockers!

 

Going to be fun to watch your progress. I think I saw your old front suspension components for sale on FB a few weeks back With all this Texas BS constantly going on around here, it's nice to have an active member somewhere in my neck of the woods

 

Always!

Yeah nobody wants to buy my junk. Guess I’ll just keep it around in case I need more used parts

 

the Internet sometimes says that 2005-2007 tundras (07 with 4.7 I assume) did not use a 7.5” reverse clam, but an “8 ifs front diff with a mid mount pinion?? And that the 1996 landcruiser had a compatible match with a high pinion. Also the rear 8.4” is really an 8” but a different design so they needed a different name? Very difficult to confirm for sure what I need, but I’m sure floating the idea of buying a wrecked 2004 v6 4x4 auto and swapping in the (entire) 4.30 front and rear diff/axles. Any reason I couldn’t just do that on my 05 V8? Splines? I need to take a class on this stuff it’s fascinating but I need hands on to understand it.

 

Second gens used the bigger front diff

 

Yeah, here’s what I was reading about front Diffs from https://www.lceperformance.com/cate...5TbeTVnkkW2D-9nAErqU16JShqYpJgZS08UKy_Qx0QoAh

Late-model 7.5" Differential: '95-03 Tacoma, '00-04 Tundra and 96-02 4Runners have a high-pinion 7.5" IFS front diff offset to the drivers side.

• Driver's side
• High pinion
• 27 spline axles
• Bolt-together "clamshell" housing design

8" IFS Differential: '03+ 4runner, '04+ Tacoma, FJ Cruiser, '05-07 Tundra: 8" IFS diff.

• Driver's side
• Mid-pinion
• Clamshell housing
• 30 spline axles
• 
  So what I want to know is what will be different in the front diff between a 2004 v6 4x4 auto (with 4.30 gears) and my 05 v8 4x4 besides the gears. Did they actually switch between 7.5” and 8”, 27-30 spline in 2004/2005? Or is this site just wrong. In my case of wanting to switch everything over from the 04 to skip disassembly, would it bolt up without issues? If I did just take the gearing out of the 04, would it fit into my housing without issues? Going to search YouTube now for someone to enlighten me on Toyota engineering

 

Site is wrong.
It's actually 05+ Tacoma, 03+ 4runner, 08+ Sequoia and 07+ Tundra with the bigger diffs.

 

Detroit Truetrac from East Coast Gear Supply. They'll send you the entire diff and you send them back yours.