4.10’s to 4.30’s. Worth It? (1 Viewer)

[GTV]

I’ve been on the lookout for a 2000-02 4.30 rear axle and front diff for a couple years. Finally found them near me out of a 2000 LC. They’re asking $950/$650 for the front and rear so $1600 total. I could then try and sell my 4.10 units to recoup some of that cost. Only potential problems are the mileage is unknown (I’ve got 209k on my truck and I’d rather not put in parts that have a lot more than that) and condition is unknown. Also the 2000 was rolled so I’m worried there might be damage, bent axle or who knows what else abuse it has been put through. If everything goes smoothly I could easily have the swap done myself in a day or two, not something you can say about a traditional re-gear. Since it’s my only vehicle right now that’s important.

I don’t need/want lockers, AHC works more than good enough for my use.

I have 33’s now and the 4.30’s will perfectly correct for that size. However, I will be going even taller before next winter but I’d prefer to do high and low transfer case gears so I can benefit from a much deeper low range than just a ring and pinion swap would provide.

What does mud think?

 

[Donaaayyy]

4.88s and 3X locking at the same time are probably some of the best things I’ve done to save diffs. I’m on 35s and went through 2 front diffs before locking. If you’re going biggger than 33s, you really need to lock it up. It’s a lot of rotational weight for ATRAC to limit and it’s not designed for that much tire imo.

 

[nissanh]

4:10 on a LC? I thought they are all 4:3 ratio. Where is the LC located? if the bull bar is intact, I might go and pull based on the location.

 

[saucebox]

That's a lot of coin for a small change in ratio...can't be that different than new gears + labor where you'll know the condition, mileage (zero), etc. I did exactly what you're proposing — after buying a locked rear axle, I think it was in the $700 neighborhood to get my front diff regeared to 4.30, including the parts. I paid to have that done locally.

I haven't personally regeared a the front diff on the 100 series, but the rear is as easy as it gets. Less than a full day's job easy, including pulling the axle shafts and reinstalling later.

 

[MongooseGA]

Meh. Without the intent of replacing an unlocked axle with a locked one and matching the front diff to that, I wouldn't think that going from 4.10 to 4.30 is worth the squeeze.

 

[Bisho]

4:10 on a LC? I thought they are all 4:3 ratio. Where is the LC located? if the bull bar is intact, I might go and pull based on the location.

The 5 speeds (2003-2007) have 4.10s.

 

[cmw]

That ARB bumper on that wreck looks pretty good...

 

[cruiseroutfit]

If your axles are in good shape, re-gearing your t-case would net a better ratio reduction for less/similar $$$. Easily done in a day, far less work than doing axle gears and you'd get 4.56 equivalent ratio.

 

[GTV]

4.88s and 3X locking at the same time are probably some of the best things I’ve done to save diffs. I’m on 35s and went through 2 front diffs before locking. If you’re going biggger than 33s, you really need to lock it up. It’s a lot of rotational weight for ATRAC to limit and it’s not designed for that much tire imo.

4.88’s would be way too agressive coming from 4.10’s. 4.56’s wouldn’t quite make up for the diameter of the new tires but it would probably be close enough. I'm not out there trying to prove anything, ATRAC does a fine job for my needs. My rim/tire package is very lightweight, my new setup will be lighter than most who are running 33's. I know it's not apples to apples but I am conscious of these things.

4:10 on a LC? I thought they are all 4:3 ratio. Where is the LC located? if the bull bar is intact, I might go and pull based on the location.

Supposedly the ARB is gone. The photo is not mine.

That's a lot of coin for a small change in ratio...can't be that different than new gears + labor where you'll know the condition, mileage (zero), etc. I did exactly what you're proposing — after buying a locked rear axle, I think it was in the $700 neighborhood to get my front diff regeared to 4.30, including the parts. I paid to have that done locally.

I haven't personally regeared a the front diff on the 100 series, but the rear is as easy as it gets. Less than a full day's job easy, including pulling the axle shafts and reinstalling later.

It's $1600 up front which is a lot of coin. I imagine that I could get at least $1000 for my 4.10's though? Good to know the rear is easy if I end up having to swap the center chunk.

If your axles are in good shape, re-gearing your t-case would net a better ratio reduction for less/similar $$$. Easily done in a day, far less work than doing axle gears and you'd get 4.56 equivalent ratio.

Ideally I would do both. T-case gears and 4.10's would be slightly under geared, t-case gears and 4.30's would be slightly over to make up for the additional tire mass.

 

[Somebodyelse5]

People regear with 33's lol

 

[cruiseroutfit]

4.88’s would be way too agressive coming from 4.10’s.



Ideally I would do both. T-case gears and 4.10's would be slightly under geared, t-case gears and 4.30's would be slightly over to make up for the additional tire mass.

Tcase gears and 4.30 axle gears gets you to a 4.73:1. Not a shabby way to go if the 4.30 diffs turn out good.

 

[Escape Artist]

Swap axles, or install new Ring and Pinions ... about $883 more to do new Ring and Pinions (done right). I just went through that myself.

I went from the 4.10 to the 4.88's as well as the low and high-range t-case gears. I have 35s and essentially is like having a stock t case and 5.30-ish gears. It is just very very slightly low geared it seems. I am about 7% lower than stock gearing with 31-inch tires. I am at about 2400 RPMs at 62mph (GPS speed) and indicating 67-68 mph. I have the 5-speed. I also put in E lockers front and rear at the same time and rebuilt everything in the T case. It ended up costing significantly more than I paid for the truck all said and done (After wheels and tires). I was naive and thought to just regear and put lockers it couldn't be more than like 5 grand ... I was WAY off.

If you are doing the labor (I do not have that luxury) then yeah, 1600 is not bad to go to 4.30s. I think it was about 1200 for me just for the labor to install the ring and pinions and lockers, and I bought the third members to Zuk myself to do it. Well worth it ... it is a LOT of work to do it correctly. If you plan on keeping the truck, don't let a shade tree mechanic install gears for you ... I got Revolution gears and they cost about 563 bucks for both. I think the new bearings and races were 720. So in parts I spent 1283 bucks (Not including the lockers of course). I don't know the labor to pull the thirds because it was being done when the T case came out to get rebuilt with the low-range sets and steering rack etc. So if you pull the thirds, your time + a shop to do the install for about 1200 pro level and maybe 8 or 900 intermediate level install. So really you are looking at 2483 to regear new and you pull the thirds. If you are in AZ there is no person better on the planet than ZUK ... he is on the forums here as well. But you have to take them to him and he doesn't deal with shipping etc ... he is in Prescott now. Very picky about who he takes as a client. I had to wait for a few months to get my place in line.

In terms of the low-range gears, I got everything from Kurt at Cruiser Outfitters and my model year needed a new input shaft and idler gear I think to make the Hi range work. I think I was in it for about 2K in parts for the gears (low and high) and another 2500 for parts to rebuild everything else (optional). I won't mention the labor because it varies ... but ALWAYS cost more than the parts lol. I think Kurt is right ... you have the data now and likely if you go with the T case low range gear and 35s in the future you will be golden on the trail. It will be a dog trying to go up any kind of hill on the freeway with stock gearing and 35s. I did tires/wheels first and ran the truck that way for a month or two before I did everything else and it was very noticeable. If you are doing just the low range you can get them for 700-800 bucks ... but if you are in there, might as well replace the seals, bearings, races etc ... but not required. Don't use Chinese gears ...

Stage 1. Do the T case low range ... don't mess with the high range underdrive. Swap the axles over. Leave the 33s for now. Drain and check diff fluid before you pay. No water contamination, metal ... good to go.

Stage 2. When you are ready to go to the 35s, trim a bit of plastic, hammer pinch welds etc, then go back and put lockers in the diffs or at least one of them. At that time they can put new races/bearings in etc. And you will have had some time to determine if 430s are a good choice of gear or if you need to go lower. With 35s and the 5-speed I think if you had like 4.67s (a fictional ratio) then your speedo would be accurate. At least this way you can keep your options open and you are only investing 1600 for now plus your time. That truck with the 4.30s looks like it was a rollover off road?? Low-speed... axles are likely fine. Go back in there with 1500 in cash and take em. You won't be able to sell your stock gears ... not even for 50 bucks so don't plan on that. I still have my stock 4.10s in my storage unit and gave up after two months of trying to sell them for 200 bucks.

Keep an eye out for a rear axle with a locker ... but I am not sure about ABS etc and sensors for ATRAC on the 98-99 100's ... if that axle swap is painless or not. That would be a great find, then put new gears in the front and do the T case and call it.

 

[abuck99]

What’s your goal- stock ratio drivability with 33’s?

4.10 to 4.30 is less than 5% change and on the 5speed- not worth messing with- in fact mechanically speaking it’s prob a step backward if the front diff is the earlier weaker pinion. Also- the stock front diff carrier in all years is prone to flex under shock load- which can (and does) end in failure: ring gear on 5spd and spider on 4spd. Swapping the diffs won’t cure that weak point- (front diff) only a locked carrier will improve that.

Fwiw 4.88 isn’t “extreme” on a 5spd with 33’s but it’s going to chew a little more fuel. Transmission won’t work as hard either, and in mountainous areas 4.88 is awesome on long mountain pass climbs, but the cost again is a mission creep- cause if you regear, better to add the lockers while your at it (or double your labor later) and that’s going to add $2200 to your bill.


The suggestion for diff regear is a solid less costly option-that delivers a 4.56 gear ratio- but doesn’t solve the weak link which is the front diff. If you drive and wheel mindful of front wheel slip and shock load- you might avoid a ring gear fail.

 

[Donaaayyy]

Per Big Mike at Marlin Crawler:

4.10:1
2256rpm = 80.019 mph

4.56:1
2256 = 71.9 mph
2509 = 80.016
253rpm higher

4.88 + 35”
2256 = 67 mph
2687 = 80.07
431 rpm higher

Stock tires & R&P
2549 rpm = 80.07

Marlin Crawler.com > Determine your Vehicle Speed

 

[hoser]

^^^Side note: R.I.P. Legendary Marlin Czajkowski...

 

[Donaaayyy]

^^^Side note: R.I.P. Legendary Marlin Czajkowski...

 

[hoser]

I ran into Marlin on a trail while driving my 100 and he asked, "Hey, does your mother know you borrowed her car?"

 

[Escape Artist]

What’s your goal- stock ratio drivability with 33’s?

4.10 to 4.30 is less than 5% change and on the 5speed- not worth messing with- in fact mechanically speaking it’s prob a step backward if the front diff is the earlier weaker pinion. Also- the stock front diff carrier in all years is prone to flex under shock load- which can (and does) end in failure: ring gear on 5spd and spider on 4spd. Swapping the diffs won’t cure that weak point- (front diff) only a locked carrier will improve that.

Fwiw 4.88 isn’t “extreme” on a 5spd with 33’s but it’s going to chew a little more fuel. Transmission won’t work as hard either, and in mountainous areas 4.88 is awesome on long mountain pass climbs, but the cost again is a mission creep- cause if you regear, better to add the lockers while your at it (or double your labor later) and that’s going to add $2200 to your bill.


The suggestion for diff regear is a solid less costly option-that delivers a 4.56 gear ratio- but doesn’t solve the weak link which is the front diff. If you drive and wheel mindful of front wheel slip and shock load- you might avoid a ring

Very solid advice here ... I didn't even think to double-check what year the front axle is coming out of ... 98-99 I think had the two-pinion diff in the font, a bit weaker than later 4 pinion diffs. Good call ...

 

[abuck99]

^ @hoser Thats Awesome. What a quote.

 

[ga12r1]

You guys are insane

Edit : Well most of y'all anyways