I'm a newb, but trying to understand the reason for re-gearing (i.e. going to 4.88 gears?)

Is it so you don't have to use your brakes on steep hill decents (lower gears creep forward slowly?)

Is it because of bigger tires?

What are the over all changes from going from the stock gears (whatever those are on a 3rd gen 4Runner), to 4.88? On normal driving?, stop & go, off-roading, etc?

What does re-gearing entail? Just install new gears in the axles ? or adding a shifter to the cab?

Thnx!

 

Welcome to the board!!! The main reason for regearing your rig is to gain back lost power from adding bigger tires. Example, if you go to 33 inch shoes, you would need to regear to 4.88s to bring back the stock power level. If you go from stock gears to 4.88s and don't get bigger tires, you will notice a large improvement in torque and acceleration, but you won't be able to cruise as fast. On the contrary, if you get bigger tires and keep stock gears, your rig will have less acceleration, but will turn lower RPMs on the highway. Idealically, you should notice no difference when going to bigger tires if you re-gear properly. Regearing involves taking the old ring and pinion out and putting new ones in. It's not something a novice should try, as you have to set the gears to precise tolerances for them to last. You don't need an extra shifter or anything like that, you're just taking out the old and putting the new, lower gears in the same spot. Re-gearing will probably run you in the neighborhood of $700-$1000 dollars, depending on labor costs. This includes two new sets of gears, master install kit, and labor. At least that's the price I've been quoted. Hope this helps.

 

Regearing is to compensate for larger tires. Most people do it to resolve back to a stock feel. I.e. stock tires with 4.11 gearing feels about the same as 33" tires with 4.88 gearing or 31" tires with 4.56 gearing.

The ring and pinnion gears in your differential (axle housing) are replaced, that's all.

If you don't regear, the truck will suffer in mileage, not have as much pickup or power.

Some people gear lower than thier tire size (i.e. 4.88's with stock tires or 5.29's with 33's) this is to give extra grunt to the truck. It is helpful to go a tad lower for towing or crawling offroad. But the truck will rev alot higher at free way speeds.

If you have a 3.4L V^ especially supercharged...gearing isn't as crucial as regearinga 4cyl. You have enough power that the high gearing won't make as much a difference. Hope that helps -Seth

 

You guys are a little off. 4.10 w/31" stock tires conversion:

33" = 4.36- no such one so 4.56, little lower than stock
37" = 4.89

calculator

 

Who said all stock gearing is 4.10 for 31" tires? My truck came with 4.10s from teh factory and had 215-75R15 tires, which was a common setup from the factory for trucks and 4Runners in 1st/2nd gen.

 

Just going off the original post, most all 4x4 3rd gens came with 31" or the metric conversion.

 

Not in every case. For example, I got better mileage with 4.10's and 265/65's than I do now with 4.30's. Explain that one.

Only thing I can figure is that I was turning less R's during highway driving. After 4.30's the R's increased which in turn lowered my mileage since I mainly drive my rig on the freeway.

I did get some zip back though. I could really tell since I have a 5-spd.

 

factory 4.88s on my 94...thanks toyota

 

Christian

Did you check your speedometer/odometer independently? Like with GPS? I found that even after regearing, mine were off a little.

 

Awesome!
Thnx for the replies- makes more sense now.

What can be done to help use the engine as a brake when descending steep hills while 4wheeling? Even in 4LO and 1st (automatic) I seem to fly down steep hills to fast- always having to brake a lot. I was told that people with stick shifts are able to creep slower, but not sure why?

 

No I haven't Glenn, but I probably should. I did check it at the airport one day by setting the cruise on 30MPH and going through one of those "your speed" trailers. It was dead on 30 (now). Only thing I can figure is that my Excel formula is/was off. I had a "corrected" formula going per some knowledgable guys here on Yotatech, and I removed it after the 4.30's. Now the formula is just the standard mileage/gallons used.

Maybe I should have left the correction in place then after the 4.30's?

 

Here's the best analogy I can think of for why gearing is the single most effective and also the most COST-effective way to increase power, or more importantly - to restore lost power when you put on bigger tires.

"Picture if you will..."
Your day job is to move boulders. You can't lift them, so they gave you a 6' lever and a block for a fulcrum. Using the lever you can, with only a little effort, move boulders from A to B all day long. Sometimes you have to move a boulder up a hill, but it's only a little harder, you can do it. Your health is great from this amount of exercise - your doctor says you're in great shape - probably gonna live forever!

One day, you come to work and the boulders are all bigger! You shove the lever under there and roll that first boulder, but now it's much harder. You can still do it, in fact the boulder even rolls farther with each application of the lever, but now you really break a sweat and you're starving at lunchtime. This hard work is killing your back, your shoulders, knee joints, wrists and everything hurt all the time, there is no way you're gonna be able to keep doing this for too long. And then there's the uphill boulder - oh no way, it's almost impossible - this is ruining your health and you're starting to age rapidly! BUT, you have no choice, it's your only job and you have to work.

So what can you do? Well, you can build more muscle. Go to the gym, buy some equipment, change yoiur diet - spend lots of time and money on equipment, vitamin supplements, trainers, etc. Eventually, with enough time and money and effort you might gain enough extra muscle mass to toss those boulders easily again.

But there is a much simpler solution. Why not just get a longer lever? Get one exactly the extra length percentage that the new boulders are larger. Now you are back to being able to do the job with just the right amount of effort, at the right speed to keep up your quota, uphill is okay again, and you feel great and are back on your sensible diet. Wasn't that easy?

You DO realise the boulders are your tires and the lever is your gear ratio - right? That food energy is fuel, and time and money spent at the gym equates to engine mods?

You can put 30% more tire on, and change your gears for $750 to get back to stock power and economy. Or-
You can put 30% more tire on, and spend thousands of dollars hoping to get 30% more horsepower, all the while killing reliability, longevity, and fuel economy. But wait! There's more! 30% more horsepower STILL won't get you back to stock, since final leverage at the differentials still has not changed - the entire drivetrain is still working under that 30% handicap, and so you need MORE than 30% more power to compensate for the losses.

Change the gears.

 

Or ,you could just do a search, I bet this is the single most discussed topic ever.

 

That's because the automatic does not let the engine compression hold you back. You gotta use the brakes instead of letting the gearing do it, and that's a challenge to train yourself (and your foot) to keep your speed down from the onset, and not lock em up with too much brake application and go sliding on down the hill, screaming in terror....

That's why I won't own an auto for offroading. Personal preference thing.

 

That is partly true, an automatic will allow some compression braking, but that catch it the slip in the torque converter. For going up a steep hill or obstacle, and automatic allows about 50% slip which is kind of like having a 2:1 "low range" gear. Allows the vehicle to move about 1/2 the speed that it would if the engine were coupled rigidly to the tranny. However, go down that same steep hill or obstacle and now the slip is the other way around, the tranny is driving the T/C and you end up with the vehicle going twice as fast as it would be for a manual tranny. Folks who have done dual t-cases in an A/T truck have reported that the biggest thing they notice is engine-controlled decents. Drop into a low enough gear to allow for the slip and the engine braking will work fine.

 

In addition to what Phil said, most automatics have higher (lower numerically) gear ratios for 1st gear.

 

<96 Runner>
I have a 96' SR5 V6 5spd that came with the 6 spoke 15'' mags and 225 75 15's from stock. I am pretty shure that the stock gears are 3.90's. I'm just about to put on 31x10.5x15's to see if I benafit or suffer. My overall plan is to put on 32x11.5's with OME coils and shocks and I am pretty shure I'll have to at least do a 4.10 swap. How much did your gears cost, and can anyone tell me if there is just limited slip kits instead of lockers for the rear? I am tired of my one wheel wonder.

 

Awesome explanation Flamed.

4Crawler- So you're saying that an auto will crawl up things better than a 5 speed....well, at least smoother. I guess that makes sense.

 

regearing does make the difference.

crawling down a hill with my stock 4.10 gears in 1st and 4lo...i could still pick up speed

crawling down that same hill in 1st and 4lo in my 4.88s...much slower

 

I swapped the entire front and rear diffs, housing and all. What I did was purchase a 96 4Runner with 4.30's, swapped everything out to mine, and installed my 4.10's on the donor rig. I then sold the donor rig for $300 more than I bought it for. So to answer your question, I got 4.30's and a locker for free, and someone paid me $100 (after selling expenses).

If you are 4WD you are going to have to swap out the front diff too, which is the worst part IMO. A body lift makes it a little easier. Also, if you are going to 32's in the future, don't even waste your time with 4.10's; go to 4.30's at least.

Yes, LSD kits do exist for a 96 4Runner. TRD makes one, and there are a few auto-locker kits out there too. Personally, I like the selectable e-locker the best. The ARB kits are cool, but they are pretty spendy with labor and on-board air, etc. I am all about scavenging parts off of unsuspecting victims.