4.88 or 5.29's

[oly884]

Well, I'm going to re-gear my truck (don't know exactly when) because of the 4WC and the 255's. I know Steve is running 5.29's and I'd like to hear his imput too.

the 4.88's would be nice for the all around useage, driving to and from work, etc. However, with the additional weight of the 4WC it might still be a bit on the doggy side (not style you sicko's) in some cases.

The 5.29's would be nice for exploring (get my low range, even lower than stock) and would be nice for the passes and what not. I don't see anything above 70 mph anymore with the camper so I have a feeling that it would work out with the 5.29's.

Comments, suggestions? (and yes, I'm getting an ARB in the rear (maybe front if the $$$ works out) when I regear)

[pskhaat]

5.29s

Why mess with something you may want to upgrade to later?

[Scott Brady]

With the 5 speed, 5.29's will be a little low but worth it.

The manual has a .80:1 OD and the automatic has a .70:1 OD.

Considering your goals with the truck and the weight you will be hauling around, I would get the 5.29's I have no regrets going with that ratio.

If you like cruising faster than 75 mph on the highways, then you will need to get the 4.88's

[DaveInDenver]

Go with 5.29 and don't look back. The ratio tables probably will indicate 4.88 to retain stock RPMs and that's true. But the tables don't compensate for increased unsprung weight of bigger tires and increased rolling resistance of a larger tire footprint. In the case of a 4 cylinder truck like mine this was definitely non-trivial, maybe less so in a V6. My RPMs are higher than stock, but not hugely (roughly 72MPH = 3000 RPM on 33x9.50 ATs at 35 psi). My mileage, though, did increase and the truck pulls much better from stoplights and climbing in the hills.

There are a couple of reasons not to go with 5.29 in Hilux axles. One is that it's a 7 tooth pinion and 37 tooth ring gear in the 8" third member, which can be a durability issue for really heavy duty use. The 4.88 is a 8/39 configuration and stock (in my case) 4.11 is 10/41. Long term, I dunno. I went with 5.29 just the same, it seems that the aftermarket 4.88 and 5.29 gears are about the same in terms of quality and longevity (which is to say they're OK, but a definite hit compared to stock).

The bottom line is packed you will love the 5.29s and mileage does not take much of a hit. This does depend on your motor to some extent, but an engine isn't going to always use less gas at lower RPMs. An engine could use less gas at 3200 than at 2800 if the torque curve and internal losses balance better there. I think in my case the 22R-E is happier cruising at 3000 RPM than the factory 2500 with the amount of payload I ask it haul around.

[crawler#976]

First off, my opinions on 5.29's and 5.71's are based on several years of hard core rock crawling in a truck that was also a daily driver. You will find other opinions on this that say the opposite is true - and that's fine. Maybe for some folks they work, but I've personally broken way to many, and watched at least a dozen sets grenade on AZ trails. Bear in mind, these are 4.0 to 5.0 on a scale of 1 to 5 trails where the skinny pedal is being depressed to the floor at low, low gear ratios. I'm actually geared pretty high at 109:1 - most of the guys are at 170:1 or better...as low as 1100:1 (Marlin's truck w/ triple t'cases!!!)

I put 45,000+ miles on the rear spooled '87 BPOS before retiring it from daily use. This is definately not "normal" use by any means. The truck is rolling on 35/12.5-15 MT/R's. In those miles, I have broken or burned up 3 sets of rear gears and one set of front gears along with a broken front Detroit Locker. Two rear sets were from breakage while crawlin, one set from improper setup. The front was also due to crawlin - when the Detroit broke it also destroyed the R/P.

IMO, 5.29 and 5.71 pinions are weak and prone to breakage under severe use. The list below is tooth counts for various R/P ratios. These are for the venerable 8", but also apply to the 8.5 non-elocker.

4.11 37-9
4.56 41-9
4.88 39-8
5.29 37-7
5.71 40-7

As the ratio changes the pinion head gets smaller and smaller. One tooth lower makes for a large decrease in pinion size. Subsequently, the smaller pinion generates more heat. I only use high quality full synthetic gear oil in my thirds and gear boxes - both tranny and dual t'cases.

With a 3.4L and 5 speed your way ahead of me on power - 22RE and G56 five speed. I know if I had the 3.4L in the BPOS, I'd be using 4.56's or 4.88's - probably the later.

Perhaps the most critical issue in regearing is proper setup. Find a shop that can give you multiple references from Toy owners. Toy thirds are very, very picky about setup - they will take a ton of abuse IF they are done right. My last spooled thrid went 30,000 miles before it let go on one of the Hammer trails. If your mechanic hasn't done a bunch of Toy thirds, I'd suggest getting them from a reputable shop via the mail. My current rear is from West Coast Diff, and has performed flawlessly. (Now I've done it, I went and put the WHAMMY on myself - I see that that guy Murphy pokin' his head over the hood again)

After install breakin is even more important than the install. Follow the instructions from your installer to avoid voiding your warrenty. My personal method is to use 90W dino juice, drive 20 miles of easy stuff at varied speed, stop and let the diff cool completely. Repeat the procedure. Drive normally (NO TOWING) until you've got 100 miles on the diff. Drain and refill with 90W dino juice. Drive until 500 miles. Drain and add what ever diff juice you like - I prefer a full synthetic 75W-90 from Valvoline. The reason I don't use synthetic on breakin is that it is TOO slick, and won't allow the gears to break in properly.

As far as hard core crawlin goes, I'll never use a Toy axle again. I've spent enough on thirds to have mildly built Dana 60's front and rear. Oh well, live and learn. Even with full width axles, by using reverse offset rims, you can come out within 4" of stock width.

So, to summerize, on a daily driver, I'd stick with the 4.88's for increased strength and longevity. Make damn sure of your setup dude, and run the best gear oil you can afford.

Just to give you the opposite side of the spectrum, take a look at Zuk's page. He says the 5.71's are stronger. I personally disagree!

http://www.gearinstalls.com/

Mark

[Scott Brady]

Considering he is running a 4Wheel Camper and is looking for more overlanding than technical trails, I would recommend the 5.29's

I went with the best gearsets and the best installers (4Wheeler Supply) and the best oils (Mobil 1 synthetic) and have had no issues in 20,000+ miles of hard, over GVWR use. No extreme rock crawling, but plenty of 3+ obstacles.

A 7.5" front diff. is not intended for heavy rock crawling anyways.

Low gears with lockers and a cerebral drivers can keep a 5.29 gearset alive for the life of the truck when used for exploration and light trail use.

[Brian894x4]

One of the best, most compelling articles I've ever seen to debunk what appears to be a myth about the 5.71/5.29 gears is this one.

http://www.gearinstalls.com/410suck.htm

The jist is that the gear contact with the lower ratio is actually more than the higher ratio gears, the ring gears are actually stronger and the most likely reason for the perceived common breakage of these gears is poor quality install. Also makes some REALLY compelling arguments for putting the lower gearing in the diffs instead of the T-case, but that's another topic.

Good read.

As for which ratio to go with, I always recommend the 5.29s for any "older" low powered Toyota with 33s or taller that is carrying a lot of weight. But if you have a 3.4 V-6 it starts to get debatable. You also have to keep in mind that Tacos had much higher gears stock than the older trucks, so even 4.88s with 33s are going to give you higher rpms than you're used too, so 5.29s will really bring you into high rpm territory and knock your speedometer way off. Now, with that said, I don't agree with Toyota's selection for Taco gearing, and still believe that 4.56s should have been used for all 31" tired Tacos, thereby making 4.88 the equvilient ratio for 33s and 5.29s for 35s.

If you had an older truck, a 2.7 4 cylinder or an auto with the higher ratio, then going 5.29s would be a no brainer. The super high overdrive would keep your rpms in check and you'd want to lower ratio to overcome the lack of gear options and super high tranny gears. But with a 5 speed and the more powerful 3.4 V-6, it's different. With my 33s and 5.29s my rpms are about 3000 at a corrected 60 mph. At 70, you'll be pushing close 3500rpm. If that sounds OK to you, then go for it.

It's a tough decision. I'm a super big fan of low diff gearing, but I'm not really sure what I'd do in your case, although I lean towards the 5.29s.

[DaveInDenver]

I agree that anything other than stock 4.10 in a hard core rock crawler is asking for trouble, just too much torque and housing flex. You are doubling or more the drivetrain torque with tires several sizes larger and way heavier on axles that were never designed to see it. I mean comparing a Dana 60 to a 8" Toyota? That guys run Marlin drivetrains and 37" tires on Hilux axles at all is pretty amazing.

Why do I think stock 4.10s are good? If my notes from my 5.29 install are right, the stock 4.10 in a 1991 8" rear diff are 41/10. That I think should hold true of 8" axles after 1982. The 8" axles before 1982 and the 7.5" diffs had 4.11 ratios, which is the 37/9 combo. Aftermarket 4.11 gear sets usually also come 37/9. This is part of the reason why I think stock gears on Toyota 4 cylinders with 225/75R15 tires (this got the über common 4.10 combo) last so long.

[Brian894x4]

Dang it, I just reread the article http://www.gearinstalls.com/410suck.htm that see that removed most of the photos and is in the process of rewriting it. Sorry.

Well, it goes something like this from memory. The number of teeth may be numerially less on 5.71 than 410, but the amount of actual metal contact will either similier or more on the 571. He made compelling arguments that most gear ratio failures are due to poor quality install, while stock 4.10 gears are installed at the factory and are obviously done properly, while ALL 571 installs are done by aftermarket installers, most of which probably don't follow the exact proper proceedure and spec.

What it really comes down too is that the gears themselves are stronger and the pinion contact the same or more, so there's no real evidence to support 571s (and thereby 529s) being weaker than 410s inherently.

He also made a compelling arugument about running 410s in the diff, and super low T-case gearing and how much stress that puts on the drivetrain, verses just running 571s and factory T-case gearing.

Sorry, I really wish his article was still there and complete as he explained it all really well.

[DaveInDenver]

He also made a compelling arugument about running 410s in the diff, and super low T-case gearing and how much stress that puts on the drivetrain, verses just running 571s and factory T-case gearing.

That makes sense, If each component in the drivetrain multiplies torque a little at a time, each is under relatively less increased stress. If you gain 20% in the diffs, that's 20% less you need to gain in the drivetrain to achieve the same amount of increased torque at the wheels.

I think the best approach is to gear the diffs to put the engine at a target RPM with your GVW and tire combination for a given cruising speed. Then gear your 4-low to bring the off highway performance into the range where you want it. This is really the fundamental difference IMHO between recreational rock crawling and recreational expedition. I expect to use 4-high and 2-high often for long periods, be that on pavement, dirt roads or whatever and so high range gearing for that useage is important.

I personally used 50MPH in 4th gear and ~2800 RPM as a goal. That ends up being my most commonly used combo for open dirt road travel. I got lucky that I had a 5 speed and could live with the slower speed 5.29 gears would require on the Interstate, but everyone is different.

[bh4rnnr]

I upgraded my 4runner(stock 4cylinder) to 5.29's from 4.88's a few years ago. I have been very happy with the setup. Before, doing the passes in Colorado, I would be in 3rd almost 2nd up the hill. Now I can maintain 4th the whole way. Off Road Performace improved to. Coming back from Moab this year(and going there) I made it on a tank and a quarter. Think we figured about 19mpg. And that was going the long way back, through La Sals and Cisco... I used Yukon gears and have been happy with them. Good luck!

[oly884]

Well, considering I'm not planning any hard core rock crawling, I think that the 5.29's will be the best route for many reasons. I think that my gas mileage will actually increase due to the shift in the power band and the weight i'm pulling.

[Scott Brady]

My mileage increased by over 2mpg, as the transmission stopped hunting between 3rd and 4th, and the LC lock-up could stay engaged.

[crawler#976]

What it really comes down too is that the gears themselves are stronger and the pinion contact the same or more, so there's no real evidence to support 571s (and thereby 529s) being weaker than 410s inherently.

He also made a compelling argument about running 410s in the diff, and super low T-case gearing and how much stress that puts on the drive train, verses just running 571s and factory T-case gearing.


I digress, please accept my apologies…

I respect ZUK, but in the world of crawlin', and he does try to make that argument, he's wrong. Pure and simple, 5.71 and 5.29 are weaker. If a 5.71 were stronger than a 4.11, the BTG crew would have been using them. In fact, over time they all went from 5.29's back to 4.11, and eventually got away from Toy axles completely. (Bent to Grind club found at: http://azrockcrawler.com/ ) Again, this is the extreme end of the spectrum. One of the early Toy guru's was Mark Mason, former owner of Kong's Offroad in Phx, AZ. He's built literally hundreds of Toy thirds, and will tell you the exact same thing I am.

So lets compare some #'s

5.71 (axle) 2.28 (t'case) x 3.95 (first gear) = 51.4 crawl ratio

5.29 x 2.28 x 3.95 = 47.6 crawl ratio

4.88 x 2.28 x 3.95 = 43.9 crawl ratio

Or bone stock

4.11 x 2.28 x 3.95 = 37.0 crawl ratio

With 5.71 you net about 39% in crawl ratio. 5.29's net a 28% increase over stock.

Unfortunately, while these numbers look great, they are only meaning full if you are running stock size tires! With 33's, a 4.88 brings you close to stock, so going to 5.29's only nets 8%!!! In reality, that's not a huge factor in torque multiplication, certainly not enough to cause problems.

So, lets step it up…

5.29 x 2.28 x 2.28 x 3.95 = 108.6:1 = two stock t’cases, the setup I’m using. That’s 2.47 TIMES the torque. Things like stock birfield joints fail frequently, and rear axle shafts can twist. The load is more than a Detroit Locker can stand in certain situations. Most commonly a Detroit fails when an upgraded axle shaft snaps, it takes the Detroit with it. This is the lowest of the torque multiplication scenarios. Cool, but not that cool. I equate it to a low-geared axle w/ auto tranny and V8 horsepower as far as the control it gives me.

5.29 x 4.00 (first of the t’case replacement gear ratios) 2.28 x 3.95 = 190.5:1. This is where real crawlin starts. 4.00 times the torque of 5.29’s and stock t’case…

5.29 x 5.00 x 5.00 x 3.95 – called the dual ultimate crawler…522:1 At this point the torque will overwhelm the stock breaks…

In all three of the setups if the axle shafts and birfields have been upgraded, the weak point is the R/P. They break frequently and it’s one of the reasons I no longer play the game. I make a fair living, but can’t afford to fix my junk after every hard trail run.

Anyway, I digress…

Mark

[Scenic WonderRunner]

There are sure a lot of numbers being thrown around here!

So I thought I would just throw out a simple one that I'm very happy about right now!

With my new engine/3.0 V6 Auto w/overdrive....on my recent trip....I got as high as 23 mpg with my stock 4.10 gears and 31" tires.

I have a very light foot, which helps a lot!

I'm Very Pleased!


.

[oly884]

Ok, so for at most, medium duty (nothing serious, just point A to point B trails) 5.29's are....?

Scott seems to like his, and every one else seems to suggest theirs. However, there are a couple of you that I can't quite judge whether you are talking about the use they would see with my vehicle or the use of some hardcore rock crawling.

[Brian894x4]

I still think Zuk made some interesting points, but I disgress too.

As for crawl ratio for a serious rock crawler, I can see how the T-case is the way to go, when crawl ratio is all someone cares about but, I've notice that most heavy duty factory 4x4s, like Unimogs, Humvees, etc, use diff and hub gearing to get the low ratios they need. With vehicle dependent expedition travel, it’s usually about reliability first, and crawl ratio and capability second, since tow rigs, friends and spare parts are usually not available like with a lot of rock crawlers. So, to that end, the argument about lower diffs verses lower T-case gears, might have some real merit. If you’re out in the middle of nowhere it might be worth sacraficing some overall crawl ratio, knowing that you're putting far less stress on critical components such as drivelines, U-joints, etc. And thus, going to a 5.29 gearset (or maybe 5.71) might make more sense than a duel T-case or 5-1 low gear T-case. I never looked at it that way, until I read Zuk’s original article.

Oly,

Scott clearly knows what he’s talking about. The only thing I'm wondering about is that I think he has an automatic, so the transmission ratios and drivability will be different than your 5 speed rig. Particularly on the highway, where his overdrive is much higher.

I believe, the 5 speed Tacos have a .83 overdrive, while the autos have a .70 overdrive. I’m going off of the older tranny specs, but I think the Taco trannys are similar. That means if the auto and the 5 speed Tacos had the same diff gears and the same tire size, the rpms on the manual trans Taco, while in overdrive would be about 15% higher. That’s pretty significant. If the auto trans Taco is doing 3000 rpm, the manual trans Taco will be doing 3450 rpm, if I did the math right.

If you have 33s and I assume your current diffs are stock 4.10s, then going to 5.29s will lower your overall ratio by about 22%. Which means your rpms will be 22% higher at any given time. Where it used to be 2000 rpm at a given speed, it will now be 2500 rpm. The current 3000 rpm will now be 3700 rpm, etc. That’s not necessarily a problem, but knowing where your rpms are going to be at, at speeds like 60 or 70 rpms will help you to decide what gear ratio is best for you.

The difference between your 4.10s and 5.29 s is about 5% more than the difference between your current 5th gear and your current 4th gear. But it’s a close enough that if you want to have an idea of what it will be like with 5.29s on the highway, go out on the highway and drive around, but leave it in 4th gear. Then imagine that your rpms will actually be about 5% higher than even that. This will be a good test, because the only real concern with going too low is on the highway in overdrive. I can’t see any disadvantage to having lower diff gears in city or trail driving. In fact, it’s usually always a major advantage.

All that said, the real question is the difference between 4.88s and 5.29s, because you're going to go with one or the other. The difference in those two ratios are a little less than 8%. So, what it comes down to is that your rpms will be 8% higher if you go with 5.29s verses 4.88s. That would mean, for example, 3000 rpms with 4.88s will instead be 3250 rpm with 5.29s. Probably not the end of the world.

I’m a huge 5.29/33” set up fan. In fact, I just recently downsize from 35s back down to 33s for the addition power and I’m loving every minute of it. I think our weight will be similar, if me not heavier. But I have half the power you do, and with my truck, I need the gearing to overcome that power disadvantage. I tend to wonder if I had twice the power, if I wouldn’t be better off with slightly higher gearing. Whereas I need the gearing to scream up moderate hills at near redline just to maintain highway speed, you might be better with a higher ratio.

There's one final point. I don't know the details, but I've heard that late model Tacos have an issue with running high rpms on the highway. Something about the computer, speed sensor or something like that not liking the high rpms and putting the computer into a closed loop mode or something like that, that could severely reduce fuel economy. Might be worth researching or maybe someone could shed some light on that here.

Given that you don’t plan on speeds faster than 70, the advantages of running 5.29s on the trail and in the city, the excessive weight you’ll be carrying, I still lean towards 5.29s if it were me, but it's a harder decision than it would be on the gutless wonder older trucks, like mine.

Sorry for the super long winded post.

[erin]

:coffee:
Oly, I basically have your truck, except ext cab -vs- dbl cab, so your alittle heavier then me out of the gate. I run the 4,88's and at 70mph, I'm pulling right at 3000rpm. My mileage on the freeway and in town, stop and go is the same due to the higher running range. I have no problems on hills on the freeway at all any more. Sometimes on milder trails that due call for low range, to offer more control, I wish for a gear in between 1st and 2nd. I think 5.29's in a manual are a little to deep, except for maybe a crawler. But like some others have said, running a higher diff, with lower t case gearing is a trend a lot of guys are moving towards to avoid grenading rear ends. But, the guys I know who have done so are more rock cralwers, so a different need all together. I think even with your additional weight, you will be fine with the 4.88's, and better off in a daily driver. Personally, if i wanted lower gearing right now, I would up the t-case gears before the diffs, because mine is a dailt driver also.

Just my 2 cents:)

[oly884]

Brian, thanks! Great post.

Erin, I too have an ext. cab. My main concern right now is the driveablility on the street more so than the trail. I'd go for the 4.88's hands down with out the camper on, but the camper on the truck is what's making me not sure which gears to go with. I guess I'll have to sit down and do some math.

[erin]

I understand your weight concerns, but I haven't noticed a problem due to any pulling power, just load capacity due to my 7 leaf packs. I just wonder about daily driving with the 5.29's, as I can barely get across an intersection now and keep it in first gear. Either way, you will definitely be going through the gears faster then before.

[BajaTaco]

:coffee:
Personally, if i wanted lower gearing right now, I would up the t-case gears before the diffs, because mine is a dailt driver also.

As far as I know, you can't go with deeper gearing in the Tacoma t-case because it is a chain driven unit with planetary gears. The physical size of the case won't allow the clearance needed to go with a larger planetary. I think the only way you can do it is to use adapters with an older t-case (if that is possible) or the dual case setup.

[DaveInDenver]

My main concern right now is the driveablility on the street more so than the trail. I'd go for the 4.88's hands down with out the camper on, but the camper on the truck is what's making me not sure which gears to go with. I guess I'll have to sit down and do some math.
It's probably a coin toss in the end, but I think my 5.29/33" combo is perfect for me. But I have a tired 22R-E, which makes a pretty significant difference. My cruising speed is around 70MPH, which puts the 22R-E right where it's happy and I get good power and economy. Your 5VZ-E might be happier with a slightly lower RPM, I just don't know never having owned anything but inline Toyota engines. As for daily driveability, I happen to like the set up of mine. In bumper-to-bumper traffic I don't have to hardly ever disengage the clutch while in first gear and starting from a stop sign is a no effort for the truck. My WilderNest is always on the truck and that extra 350 or so pounds of weight is noticeable. When I do take off the 'Nest for a cleaning or refurbish, the truck feels much different. The change is enough that I think 4.88 with an open bed would be better. But when I do put it back on, I am reassured that 5.29 was the right choice. With anything taller I would be struggling. Gear the differentials for what you want the truck to drive like normally and regear the transfer for off highway gearing. The optimal diff gear is not always the absolute tallest, it's the one that puts the engine at a desired RPM with a tire size/transmission ratio/highway speed combo. Your decision variables are unique. I have an old engine, truck at rated GVW and higher elevation, which pointed me towards lower gears rather than higher. If I lived at sea level, 4.88 might have been easier to live with. But starting with a 115HP at sea level (maybe 85HP now?), add 185K miles and 4400 lbs of truck and my little motor really likes 5.29 gears.

[Howard70]

Hello:

I'm new to the forum, been soaking up ideas for the setup of our new (to us) 2004 Doublecab. After 20 years we've decided to "upgrade" from our 1987 4runner.

I'm curious about the use of the ETC setting and gearing. If you ran 4.88 gears with the 255/85/16s and used the ETC "on setting" when you were loaded or towing something, would that give you an effective gearing between 4.88 and 5.29?

I understand that the ECT slightly alters the shift points of the automatic transmission, but I don't know how much. I've played with mine a bit (I'm currently running 4.10 with 265/75/16), but haven't really concluded how significant the setting is.

Howard L. Snell

[crawler#976]

As far as I know, you can't go with deeper gearing in the Tacoma t-case because it is a chain driven unit with planetary gears. The physical size of the case won't allow the clearance needed to go with a larger planetary. I think the only way you can do it is to use adapters with an older t-case (if that is possible) or the dual case setup.

You are correct Sir! Marlin is da man for gear reduction.

http://www.marlincrawler.com/htm/transfercase/taco_box.htm

[oly884]

There's another, lesser, issue. It's not quite as easy for me to get lower gears in the T-case without spending some good cash, so 4.88's and t-case work would be a double hit to the bank.

After some calculations, my truck with 5.29's going 67 mph in 5th gear would put my truck at 3k rpms.

assuming I used this eqn. right:

http://www.4lo.com/images/gearratio-formula.gif

Now with the t-case not engaged, it's 1:1 right? I know it's 2.28:1 with it engaged. Just want to make sure.

[Brian894x4]

That's probably pretty close. The tire size and overdrive ratio are the big variables, because your 33" tire, my 33" tire and Scott's 33" tire could all be different hieghts and may differ as much or more than an inch. And all of our overdrives are different. I think yours is .83, mine is .85 and Scott's is .70

My truck with 33" MTRs, in 5th gear on the highway, with 5.29s at a GPS indicated speed of 60 mph is about 2900 rpm. My 5th gear is just a hair lower than what I think yours is.

But your rpms at 60-65 mph with 5.29s should be something close to 3000 rpm. The question is how will your engine perform running at that rpm all the time. I think the engine can handle it fine, but I wonder if your fuel economy might suffer, whereas Scott's fuel economy improved, because his rpms were too low on the highway to begin with since his automatic has such a high overdrive.

It would be interesting to see what Scott's truck's rpm is at 60 in overdrive. With his taller than normal 33 and auto trans, I'll bet his rpms aren't much higher than 2400-2500 at a corrected 60 mph. Is that right Scott?

The Toyotas do have a 1-1 high ratio, unlike some makes like the Land Rovers, etc. I believe the 2.28 low range T-case ratio is only in the geared T-case ratio and the geared T-cases were only used in 22RE trucks with W56 trannys and manual hubs. I "think" your chain T-case has the same 2.56 ratio that the older V-6 trucks got. If so, you enjoy a slightly lower T-case gearing than I do, which is nice to have.

[erin]

Yes, the chain drive case is 2.57 , unless I've been miss informed. The crawl ratio in low is great for a truck w/o dual boxes, running intermeadiately difficult trails. But, I have already run into a couple of areas where lower gearing would have been helpful w/ my manual. I think either way you'll be ok. This morning on the freeway @ 70 mph(uncorrected), I was right at 2900rpm, so with the 5.29's, you'll be right where I said I was before, 3000-3100rpm, sorry about the mistake.

[SOAZ]

Hello first, I'm a newb.
Can someone explain to me why you wouldn't just want to the the marlin instead of touching the gears?
Gears are about a g installed and the marlin is 1300 or so?
I know I'm missing something so can someone explain it?

[oly884]

It's for driving around too. If you get lower gears in the axles it fixes the gear ratio when you put larger tires on (like I did). A marlin is great if you're going to spend a lot of time in low range, where as, I'm not going to be spending enough time to make it worth while.

And I think I've decided to go with 4.88's. 5.29's ar just a bit too low if I ever take the camper off. We'll see though.

[SOAZ]

Okay, so a marlin will of course give you the ultra low gearing when you're in the low gear setting, but it won't also give you a lower normal running gear if you specify thats what you want?

Totally off topic: How are those tires holding up? I trust the BFG quality from years of baja racing, but the cooper st looks like a much better daily driver tread pattern. Have you had them aired down on some sharp rocks? I don't want to get a cut in the sidewall!
(for anyone who wants cooper st 255/85/16 they are $149 at arizona "jeff furriers western tire centers" right now.

[highlux]

I am in a similar boat with Brian. I have a 2.8D with 5 speed and 5.29s. I used to have 35x12.50s, and that was great for highway mileage, but not so much power.:( I want to "downgrade" to a +/-34x10 tire, but for now I have 31s. Trying to decide on what tires and between keeping the 5.29, or going to 4.88. Don't really want to have to get swampers for such a different siz so I am really liking the 255/85 size the more I read about it...but will have to spring for new 16s then.

[Grim Reaper]

If you haven't seen this try it.
http://www.grimmjeeper.com/gears.html

[oly884]

Okay, so a marlin will of course give you the ultra low gearing when you're in the low gear setting, but it won't also give you a lower normal running gear if you specify thats what you want?

Totally off topic: How are those tires holding up? I trust the BFG quality from years of baja racing, but the cooper st looks like a much better daily driver tread pattern. Have you had them aired down on some sharp rocks? I don't want to get a cut in the sidewall!
(for anyone who wants cooper st 255/85/16 they are $149 at arizona "jeff furriers western tire centers" right now.

They've held up for 25k miles just fine. That's over sharp rocks to nothing but ice. Aired down to 40 PSI. I'm getting another set when these guys are done, probably have around 30-40% left.

[SOAZ]

They've held up for 25k miles just fine. That's over sharp rocks to nothing but ice. Aired down to 40 PSI. I'm getting another set when these guys are done, probably have around 30-40% left.
Wow, 40 psi? What do you run them at stock?
I ran my old 285/75 bfg at's at 35 on the road and 20 offroad.

[oly884]

Wow, 40 psi? What do you run them at stock?
I ran my old 285/75 bfg at's at 35 on the road and 20 offroad.

Well with the weight of the camper, the rears are running between 35 and 40.

The fronts will range from 30 to 35 and I've aired them up to 40 to see how mileage was but ended up going back down to about 32 due to crowning.

[SOAZ]

Oh, okay. For a second I thought you were saying you were aired DOWN at 40psi. That would mean you were somehwere in the 50's before you aired down. It didn't make much sense to me. Now I get it.

[oly884]

haha, np man. When I aired down, I was at about 17 PSI.