shiftMX

I was wondering if I put on a 3" revtek lift and put some 285/75/16's on my 2wd SR5, would I have to regear? I did a search to put 305/70's but that seems like way too much work. I also know I am going to loose power and gas mileage, but would I gain it all back by regearing?

Jboy

If you have a V6 engine then it is not totally necessary to regear, but if you have the 4banger then it would be better to regear. I have 285`s on my lifted 4runner w/V6 and still have plenty power left.

keisur

Even if you have a V6 I would suggest regearing. I noticed alot of power lost in 4th and 5th gears and also acceleration from stop was a crawl before I regeared and had 285's. Gas mileage also sucked. Since I regeared to 4.88's I have all my orignal power back in the high gears (plus some) and acceleration from stop is fast, needed to cut people off on the way to work, . After going to 285's you would only need to regear to about 4.30-4.56 to get back to the stock performance. I went to 4.88's because I wheel and wanted more power but it is also my daily driver and I need to get on the interstate and go 70+ so I couldn't go any higher without really spiking the rpm's at those high speeds, even in 5th gear.

I would suggest going to 285's and regearing. before I regeared I would have told you not to regear but now that I know the difference I wish I had regeared along time ago.

nightsurfride

I was always under the impression that bigger tires = less power, but better fuel ecconomy. It makes sence too because with a larger tire the distance is greater, yet the axle spins the same(better gas mileage) Also, bigger tires make it harder for the gears to turn which = loss of power. I have 285/75/R16 tires and I have noticed a loss in power (V6), but not an amount that makes me want to regear. I would have to agree with Keisur though: if I did regear, I probably would think that I should have done it a long time ago.

keisur

no, because unless you regear your engine has to work harder to turn those bigger tires which means more gas burned because you always have to floor it to get it moving. If you were always going on long hauls like 8 hour interstate driving at high speeds then you might save a little gas but it's the stop and go that makes the engine work really hard with stock gears and 285's that cause the poor fuel economy. I was getting about 14 mpg with 4.10's and 285's and now I get about 18 mpg with the 4.88's since the engine works less to get it up from a dead stop or slow speed. Plus acceleration is faster than it was even stock. Alot of 4runners I catch at a light are surprised when I can jump off the line faster than them and then pull away from them. I'm sure I don't get 18 mpg when i do that though,

hehe, your right, if you did, you would. I can chirp the tires in 3rd gear and the engine braking power I get really scares the crap out of tailgaters when I decide to "no-light brake" on them. .

AznSky

So how much would it really cost to regear? I think I have 3.90's cuz my truck came with 15" wheels and 235's, and now I have 265/65/16's and my runner is slow and boggy as hell. Plus the gas mileage is insanely low I believe. I only get around 240-260 miles per tank.

Factoring in the cost of the gears, would I need a new carrier or housing? And installation, because I don't even have a clue where to start. How much would it be?

And throwing in the optional locker, how much would that add? If I were to lock it, I'd probably go arb air locker.

Oh forgot, if I'm regearing the rear, I have to regear the fronts too huh? I'm thinkin 4.30's all around, but I'm just asking for estimate of parts and install.

sorry for the hijack.

Jboy

I had both my previous Toy p/u`s regeared and they were $1K for parts and labor.

keisur

If you feel confident you can do the install yourself, just buy a complete third from one of the drivetrain stores already setup and all you have to do is drop yours and pop the new complete 3rd with the new gears in. I paid about 1000 bucks each (I got ARB's and 4.88's though) and installed the complete thirds myself. it was relatively easy, just time consuming.

yes you have to do both, otherwise you will bust something if you engage 4x4 with a different ratio in front and back. ARB's are a good choice, hehe.

nightsurfride

That's a good question. Do you need to regear the front? I would think you wouldn't for on road perposes because obviosly you're not using the front, but in 4x4 I am interested if it is nessesary.
Also, is regearing as simple as removing the planetary gearset and replacing with the new one, or are shims and measuring back lash with a dial indicator, along with other install presedures part of the install as well? I have done some surches, but find most folks discussing the procedures for the break in period and not the details of the install. Know a thread I could check out, or a general run down on the install? Thanks.

keisur

read my second paragraph above.

keisur

it is alot harder then that. it requires some measurement tools like a dial indicator for pinion depth and ring gear backlash. I wouldn't recommend doing it yourself unless you are extremely confident and have alot of patience. I was going to do my own until I found that I could order a completely setup 3rd with gears and ARB installed and setup professionally and a front diff with gears and ARB installed professionally. I figured I'd just return the core to them and it would all equal out. Bearing preload is also an issue. the rear would be straight forward but the front clamshell would be a pain. I could xerox the ARB install instructions that came with both my front and rear lockers if somebody wants me to mail them to them. it covers a detailed install of the 7.5" clamshell front diff and the rear one covers the 8" rear 3rd.

nightsurfride

Nice! I know I could do the front and rear install myself, as long as I had written instructions and specs., but I don't know if I really would want to put the energy into doing it. I hate other techs touching my vehicles, but this would probably be a situation were I would bite the bullet. Thanks for your insight, it is much appriciated.

keisur

look at these:

Front Install by Lars Dennert
Rear Install by Scott Wilson

keisur

I agree, I've had too many bad experiences which is why I will try almost anything myself first because I am capable and then take it somewhere if I absolutely can't get it.

shiftMX

I am curious to know what gear ratio would you guys recommend for me? I have a 2wd and I don't do any serious off-roading. I will be pulling a small enclosed trailer with a pair of dirtbikes in it though so I want to regain all the power I lost and gain extra if possible. I also plan on a supercharger in the future

keisur

what size tire? if stock size then leave them at 4.10's.

check this out: for stock performance you want to get in the middle of the skin colored boxes.

shiftMX

i wanna put 285/75/16. and would you recommend the 3" revtek lift for my truck since i don't do any serious wheeling?

nightsurfride

I have the Revtek 3" and couldn't be happier. It was gravy puting in, and I liked they way they made the kit vs. the $.

nightsurfride

4Wheel parts has a color coded chart that shows what you are asking:4Wheel Parts There is another site that will do all caculations for you, but I can't find it in my mess of a desk.

keisur

yep, in my opinion, that would be the way to go. think about it hard though, if you decided to start wheeling or you end up wanting to add a heavy duty aftermarket bumper like mine and then a winch you will have wished you got adjustable front coilovers. but if you don't see ever doing that stuff then I'd say, the revtek kit is perfect. make sure you get the revtek front diff drop spacers with the 3" spacer kit.