I am exploring the re-gearing of my '09 Tacoma. 32" tires, 40 gal fuel tank, front & rear bumpers, steel skid plates, recovery gear, sometimes AT in tow etc. have created a situation where my stock gears just cause too much down-shifting. I know there must be a thread somewhere in the forum (I searched unsuccessfully) that addresses formulas for determining the right ratio (tire size, rpm at various speeds, etc), sources for buying the gears, and some advice on what has and has not worked. If someone could point me in the right direction it would be very much appreciated. Thanks!
Re-gearing '09 Tacoma
- Thread starter cwvandy
- Start date
cam-shaft
Bluebird days
4.56 ratio East coast gear supply. A 4.30 would be perfect in my mind, but they do not make one. Have only heard good things about them and fair priced.
http://eastcoastgearsupply.com/
Cam-shaft.
http://eastcoastgearsupply.com/
Cam-shaft.
zolo
Explorer
If you are running a V6 rig then 4:56 is the lowest you can go without changing carriers If I'm not mistaken.
Any lower than that and you will need carriers from a 4cylinder that came with 4:10s stock. Then a 4:88 would fit.
Or if you are getting a carrier locker this would address the issue as well.
Any lower than that and you will need carriers from a 4cylinder that came with 4:10s stock. Then a 4:88 would fit.
Or if you are getting a carrier locker this would address the issue as well.
Mrknowitall
Adventurer
Your stock tires were between 680-683 revs per mile. you went to a tire that may well be (265/75 Duratrac) 657 rpm. On top of that, it sounds like you run around with as much as 1000# extra load, plus trailer.
Your truck's gear ratio was chosen to give a good balance of EPA fuel economy and unloaded driving (dealer test drive) feel.
Your truck came with 3.73 gears. Multiply by your OE TRPM divide by New TRPM=3.87. If you just drove the truck emplty all the time (and had less built-in weight), then the 3.91 gears Toyota puts on the MT FJ Cruiser and V6 4Runner would be great. Given all the extra weight though, and (gasp!) planning ahead for the future, you'll want a little more than that. 4.56 gears would work well. IIRC, you'll need a new front carrier, so it would be a prime opportunity to get a front ARB.
Your truck's gear ratio was chosen to give a good balance of EPA fuel economy and unloaded driving (dealer test drive) feel.
Your truck came with 3.73 gears. Multiply by your OE TRPM divide by New TRPM=3.87. If you just drove the truck emplty all the time (and had less built-in weight), then the 3.91 gears Toyota puts on the MT FJ Cruiser and V6 4Runner would be great. Given all the extra weight though, and (gasp!) planning ahead for the future, you'll want a little more than that. 4.56 gears would work well. IIRC, you'll need a new front carrier, so it would be a prime opportunity to get a front ARB.
zolo
Explorer
If its a V6 then yes the carrier just is not the right size for anything lower than 4;56s...
BUT if that gear ratio works for you then no, Its doesn't complicate a thing and your good to go.
From the other post Ive read, 4:56s is your ticket...
Mrknowitall
Adventurer
Zolo- are you sure? I was just perusing this:
http://arb.com.au/media/products/air-lockers/application_chart.pdf
and I could swear that the split is RD111 for 3.73 or smaller and RD121 for 3.91 or taller. Then again, if their guide is as accurate as Toyota's press information....
http://arb.com.au/media/products/air-lockers/application_chart.pdf
and I could swear that the split is RD111 for 3.73 or smaller and RD121 for 3.91 or taller. Then again, if their guide is as accurate as Toyota's press information....
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Dave Bennett
Adventurist
Just my .02, but it sounds like you're going to be heavy. 4.88's are niiice... 
If you have a 6spd, there is only one choice: 4.56. If you have the auto you could go 4.88. The auto and manual have different transmission gearing. The 4.56 will give you a better cruising gear for higher highway speeds and the 4.88 will be better offroad and climbing mountain grades on the highway. I have a fairly heavy 07 and pull a trailer. My typical highway speeds are 65 and under. I would choose the 4.88 with the auto. My truck is a manual 6spd so I have the 4.56. Here is a calculator that will allow you to run the numbers and decide what is best for you. http://www.grimmjeeper.com/gears.html The 4.88 may indeed require the new carrier, not sure. ECGS is the best source for that info.
Glorybigs
Adventurer
Just my .02, but it sounds like you're going to be heavy. 4.88's are niiice...
Ditto, all the gear ratio calculators only crunch ratio numbers and do not take into account all the extra weight.
I went with 4.88 Nitro's w/solid spacer from ECGS and a RD121 up front.