Re gear to 4.88's or not?

[Bull Moose]

What is the difficulty of a regear? Is it a relatively simple change, or incredibly involved? Is it as simple as swapping the ring and opinion, or are other components affected?

If I was to have a shop do the change what kind of cost is associated vs doing it myself? I reread the thread, but did not see these questions addressed.

 

[pfran42]

Slippery slope is the best way to put it. If you are paying to have someone open up your diffs to re-gear them, why not just add air lockers while you are at it? 2 birds, one stone with the labor but now you just added $2500 to your shop bill.

 

[CRUIZIN]

I politely disagree with this part of your statement but fully agree with the rest. I would do 5.29s in a heartbeat with 35s.

5.29 with 35s and a V8 is overkill IMO, the ring gear gets smaller as the ratio goes up, weaker too.

And of course, most everyone who has regeared is going to tell you to regear. Personally its benefits do not outweigh the costs for me.

If you are looking at locking front and rear because you don't have a factory rear locker, then regearing would be a no brainer, but since I have the factory e-locker and 4spd with 4:30s, and only plan on going up to 33s, then regearing will not be anything I would consider for my 100.

Now, if you are rock crawling your rig, and its a toy, running 35s or bigger, regearing would probably be needed, but how many ppl are hardcore wheeling their 100s?

 

[Nottajeep]

I am actually back on the fence with this subject... the only definitive way I can make this decision is to buy my tires first and drive in various situations for a month or two. Then, the need for new gears is decided for me.

I am being quoted $1300-$2000 labor to install F/R lockers w/ compressor. Gears would be no added labor to install.

I would love a 34-35" tire, but it is not worth rubbing issues. Based on my current setup, I may have to settle with a 33" tire.

 

[jonharis]

Good call. I ran the tires for 10k before regearing. That just made me more sure I made a good decision.

 

[OregonLC]

the ring gear gets smaller as the ratio goes up, weaker too.

While you buy rings/pinions in sets, I thought the ring size went up with the lower ratio. Isn't the ratio pinion teeth:ring teeth? So a 1:5.29 would have more teeth (and a larger gear) on the 5.29 side, right?

 

[Romer]

I am actually back on the fence with this subject... the only definitive way I can make this decision is to buy my tires first and drive in various situations for a month or two. Then, the need for new gears is decided for me.

I am being quoted $1300-$2000 labor to install F/R lockers w/ compressor. Gears would be no added labor to install.

I would love a 34-35" tire, but it is not worth rubbing issues. Based on my current setup, I may have to settle with a 33" tire.

I have been running for2 months so far after installing the lockers with stock gears. It wheeled fine when I went to Ouray and is great on the Highway. I have 33.2" tires and probably could go to 34's without an issue. I do have the 5 speed which has lower gearing to begin with for crawling down hill.

35" tires are cool. My daughters with there 33's (one is a 4runner IFS) would follow me everywhere I went without a problem. The only place I went by myself was the Rubicon

 

[Letsgomoreplaces]

Installation Guides - Nitro Gear & Axle

But if you are doing lockers anyways, the addition work/labor is minimal.

What is the difficulty of a regear? Is it a relatively simple change, or incredibly involved? Is it as simple as swapping the ring and opinion, or are other components affected?

If I was to have a shop do the change what kind of cost is associated vs doing it myself? I reread the thread, but did not see these questions addressed.

 

[Letsgomoreplaces]

Are you near Dallas/ft worth? there are a couple places I could recommend.

I am actually back on the fence with this subject... the only definitive way I can make this decision is to buy my tires first and drive in various situations for a month or two. Then, the need for new gears is decided for me.

I am being quoted $1300-$2000 labor to install F/R lockers w/ compressor. Gears would be no added labor to install.

I would love a 34-35" tire, but it is not worth rubbing issues. Based on my current setup, I may have to settle with a 33" tire.

 

[elkaholic]

While you buy rings/pinions in sets, I thought the ring size went up with the lower ratio. Isn't the ratio pinion teeth:ring teeth? So a 1:5.29 would have more teeth (and a larger gear) on the 5.29 side, right?

Uhhh .. not really. Most folks talk about ring gear diameter when the mention size (ie Ford 9"). The ring gear diameter pretty much stays consistent from ratio to ratio and is set by the contraints of the housing. The pinion will change in diameter and the ring gear will be thicker or thinner to continue to mesh with the ring gear.

You are right that the number of teeth on the ring and the pinion "create" the ratio so in general, as you go lower (higher numerically), the pinion gets fewer teeth. The actual number of teeth on each gear gets to be a fairly complex math / geometry / engineering problem.

 

[CRUIZIN]

While you buy rings/pinions in sets, I thought the ring size went up with the lower ratio. Isn't the ratio pinion teeth:ring teeth? So a 1:5.29 would have more teeth (and a larger gear) on the 5.29 side, right?

Ring gear decreases in thickness the higher you go in ratio, pinion gear gets bigger in diameter.

 

[OregonLC]

Ring gear decreases in thickness the higher you go in ratio, pinion gear gets bigger in diameter.

Not trying to argue with you just not following the math. Wouldn't a bigger pinion be a lower ratio (taller gear)? Bigger pinion = more teeth = lower ratio = taller gear. Or am I misunderstanding what you're saying?

 

[Letsgomoreplaces]

"Higher" Gear Ratio aka "Taller" gear ratio = Lower Numerical. IE 4.10 is "Higher" geared than 5.29.


5.29 would have less pinion teeth than a 4.10, thus smaller pinion diameter. The ring gear on a 5.29 would be thicker however, to make up the distance so they mesh.

5.29 is kind of moot to discuss as its not really an option anyways.

Not trying to argue with you just not following the math. Wouldn't a bigger pinion be a lower ratio (taller gear)? Bigger pinion = more teeth = lower ratio = taller gear. Or am I misunderstanding what you're saying?

 

[Nottajeep]

Are you near Dallas/ft worth? there are a couple places I could recommend.

Yes sir! Please divulge.

 

[Javelin]

Those of you with 33s and 4.88s with the 5 speed what are your highway RPMs at around 65mph?

 

[jLB]

Those of you with 33s and 4.88s with the 5 speed what are your highway RPMs at around 65mph?

If my math is correct:

A750 (.713), 4.88 gear, 33" tires, should be ~2312RPM @ 65MPH
A750 (.713), 4.30 gear, 33" tires, should be ~2169RPM @ 65MPH
A750 (.713), 4.10 (stock) gear, 33" tires, should be ~1923RPM @65MPH
A750 (.713), 4.10 (stock) gear, 31" (stock) tires, should be ~2068RPM @65MPH

The bigger question is, why would you want to run 4.88s with 33" tires on a 5 spd car?
The lower 1st gear of the 5 spd A750 really makes the move to 33" tires painless, compared to the older 4spd models.

 

[Javelin]

Just curious. I am planning to run 34s eventually but want to get LOckers soon. So just seeing if the highway rpms are tolerable

 

[SanDiegoCruiser]

Just curious. I am planning to run 34s eventually but want to get LOckers soon. So just seeing if the highway rpms are tolerable

99 100 series running 4.88's on 285/75/17 Toyos 34". 75 mph = 2800 rpm.
Regearing has been the most important "mod" I've done to my rig.

 

[DJCloz]

99 running 4:88 (only after I broke my front Diff). And I did have a ARB locker too. At first, the cost to buy gears when installing my front ARB was too much to do at the same time. I honestly thought getting a front locker would make my front diff bulletproof, but I still managed to break it. I was doing some serious rock crawling though. I am running 305/65/18 KO2 tires. Appx a 33.6? I didn't feel under powered prior, but I just didn't know any better. Now that I do have 4:88 the truck is more peppy around town and less sluggish. It feels pretty good. Specially considering I have full slee bumpers and sliders to add a lot of weight. The only downside to the new gears in my opinion is the lack of top end for my 4 speed. On an open hiway road trip I am usually driving between 75-90 mph, before I was at 3k rpm at 90, however now I am at 3k rpm only going 80 mph. Anyone in a 4 speed with 4:88 running 35's? What's your 80 mph rpms? Or has anyone ever thrown a 5 speed in a early LC?!??

 

[sugarsam]

^ Above question anyone?