HELP on 2WD Capabilities

[OneBadExpSport]

Uggg! OK, I'll finally admit it. I own a 2001 ExpSport, and it's a 2WD (something that is shunned upon in the offroad world). =( SORRY. It looks bad a$$ with my 4 inch lift, 33x12.5 Pro-comp MTs, modular chrome Rock Crawler wheels, and Westin safari bar with Delta offroad lights, but I don't know if it can live up to the name. I plan on getting a Flowmaster exhaust and an intake it (unsure of which brand) to add more horsepower. I will also customize a front skid plate and buy a new set of shocks (also unsure of which brand). Any suggestions?

I was hoping some of you guys had any suggestions on how to make this rig as close to 4x4 capable as possible. Also, if you could shed some light on what type of terrain, hills, etc a 4x2 is capable of. It can climb pretty strong, but I'm scared the lack of traction up front will cause the X to spin and then flip over during steep climbs. I've already invested $1000 in this with another $1000 in the very distant future, and I want to ENJOY THIS RIG!

Any help would be greatly appreciated. Thanks a lot.

Brian

 

[Alec]

one of the best things you can do is put a locker in the rearend. this will help in lower traction situation. it's my experience that a properly setup 2wd can hang with 4x4s in most situations other than sand or other situations where you really need front pull.

If you really want to get aggressive, look into adding an underdrive unit or a transfercase so you can have 2wd Low-range.

 

[OneBadExpSport]

I have a couple of questions:

First, which locker would be best for my vehicle and for which axle? I already have a factory rear limited slip differential. should i just invest in an air locker, or are the automatic ones good enough? Have you heard of the Offrotec selectable vacuum locker? It sounds promising and costs about as much as an air locker. Also, the explorers have Dana 35 axles, right?

Secondly, can you describe what an underdrive unit and transfercase does? Where would I find them and for how much? Thanks a lot, Alec, for your help.

Brian

 

[Crankcase]

Originally posted by OneBadExpSport
I have a couple of questions:

should i just invest in an air locker, or are the automatic ones good enough?

Also, the explorers have Dana 35 axles, right?

Brian

If you can afford to invest in an air locker, go for it. The ability to turn it on and off would be well worth it...
Very costly though

The 4WD Explorers have a Dana 35 front axle.

 

[Alec]

I myself have an Eaton posi in the rearend. I can get away with the posi due to the power I have available, but most 2wd owners should get a true selectable locker IMO. The ARB is a good option as this gives you an air compressor to run tires and is fully selectable. The new designed ARB is a fairly good unit. However, keep in mind that if it breaks then you're most likely stuck.

You have a 31 spline Ford 8.8 rear differential.

Always go wheeling with someone else, preferably someone with 4x4. Have all the correct gear necessary. Also keep in mind that if a 4x4 has something go wrong with the rear drivetrain they can limp out on the front. You don't have that option, so everything needs to work!

Honestly a major reason I do so well with only 2wd is that I have the power to make up for the lack of low range. Without power or low, you'll be at a great disadvantage. You may want to speak to Gopher, he's anothe 2wd that goes wheeling often. There aren't that many of us 2wd'ers that do hardcore stuff, but there's a reason for that......

 

[Nick C.]

I guess I offer more questions than answers. But...I went wheelin the other day. Nothing major I found some trails and I thought I'd take my 96' and my friend was there with his 98' Cherokee (2" lift with 31's). Neither of us had to use 4 wheel drive for the actual trail it was just the mud that required it. Traction was never a problem. It was more of ground clearance that made the difference of where we could go.

So could it just depend on what kind of wheelin you do that depends on 4 wheel drive or not? There are quite a few 2wd's that tear it up offroad on this forum.

 

[Alec]

Yes, it does depend on what you want to do; how often; and how far away from home (how stout you want the truck in case you need to tow it home).

1badsport already has the clearance and tire issues covered, the question is gearing and traction aids from this point.

 

[OneBadExpSport]

Alright, so here are my current financial options. I can either invest in package to increase my horsepower and comfort: intake, exhaust system, shocks, or I can invest in a selectable locker. Which one would you suggest? The OffroTec locker gives you the option of manually locking it using a bolt if the system fails. Would I just need the Ford 8.8 locker for the rear or would I also need front and rear ring and pinions? I am still unsure of what the ring and pinions do.

I'm assuming I need my gears to be around 4.1 or 4.88, instead of 3.73. What options are available for that?

Alec, how did you juice up your explorer so that you don't need a transfer case, they're freakin' expensive!

And thanks a lot, guys, for all your help so far. I never realized the potential for 2WD.

Brian

 

[Alec]

I think it would be prudent for you to learn how differentials and 4 wheel drive work. Try www.howstuffworks.com and type "differential" into the search. You'll come up with all the info you need right there.

The ring and pinion is the gear set which transfers power from the driveshaft to the axles via the differential. You do not have a front drivetrain (hence 2wd only) and thus need to worry about the rearend: the 8.8.

4.10 or 4.56 would be better for you than 3.73 to turn those 33" tires. I'd lean towards 4.56 for you to make up for the lack of low range. You should swap the gears at the same time as the locker install to minimize labor charges.

I've never heard of the locker you mention, make sure they have one available for your application. Maybe other members have heard of them, but I haven't. I'd lean towards the ARB for you of those that I have experience with.

I still get stuck because I'm only 2wd. However, I have an Eaton posi in the rear, 300 hp, and 375+ torque to help me along

 

[OneBadExpSport]

Ok, I'm almost clear on everything. I'm going to get a selectable locker. What would I need to get the gears to 4.56? Will that fix up the tach, sped, and od -ometer problems? Also, what power upgrade options do I have? Thanks

Brian

 

[Alec]

For power you have some easy bolt on options: intake, exhaust, chip (or programmer). Many many threads on these topics. My intake and exhaust thoughts: Dead Link Removed

As for the speedo, you'll need to calculate the % difference your tires made and the % difference the gears will make. See if they equal. If not, you'll need your computer programmed to get it right, but you may be able to do this with a power programmer, www.hypertech-inc.com . This would be great for power, too.

To swap gears you'll need the gearset and install kit; and like I said before should do the locker at the same time. Depending on where you go to get them installed, you may be better off having them get all the parts (probably minus the locker). Actually, you're in Orange County: might be good to give your local 4 Wheel Parts a call. They should be able to provide everything and do the install for a good price. I was very pleased with their gear install on my truck. They're not the cheapest, but they're great

 

[DocVijay]

If you're going to switch gears, a 4.56 may be little to low if you do much driving on the interstate. The engine will be revving really high and your gas milage will go way down. Keep that in mind. A 4.10 may be better. I went with a 4.10 because I drive on-road.

 

[OneBadExpSport]

Alright, approximately how much will installation be for the locker and rear-axle ring and pinion. At the 4wheel parts website, the gears are 164.95 and the air locker is $626.95. Are those good prices? I'm going to look into the new vacuum locker. Here's the website, if you're interested. KILLER AXLES

Also, if I had a few extra hands to help me, would I be able to do it myself. The most complicated project I've done on my truck was the body lift. Saved me 400 bucks and I'm damn proud of that since 4wheelparts and extreme truck parts wouldn't do it for me and told me I shouldn't attempt it on my own! So if I could save myself another 400 bucks, that'd be great.

One final question. Can someone explain to me how a selectable locker works. I know that I have to push a buttom and a few seconds later, the locker is engaged and the gears get locked. I don't understand the benefit from this. Basically it just sounds like a fancy braking mechanism for the rear wheels. Can someone clarify this for me, please.

Thanks a lot for the help. I would never have known that I had Spline 31 8.8" axles. I don't even know what it means, but it sounds cool.

Brian

 

[Mbrooks420]

The locker doesn't stop the wheels, it locks one wheel to the other. So both of the rear wheels turn exactly the same. Now you have limited slip, and after you give it so much power it slips and lets one wheel spin. I don't think this is something you want to do yourself If you don't already understand differentials. Not easy and plenty of room for error.

 

[OneBadExpSport]

So basically I'm paying over $700 to counter what the Limited Slip Differential does? Damn technology. What differentials do the older trucks have?

Brian

 

[Mbrooks420]

Limited slip is great. It's great for on road, and decent for off road. A selectable locker lockes both wheels for the most traction a 2wd can buy. Plus you can turn it off so your truck is streetable. You loose the limited slip with the locker.

What differentials do the older trucks have?

The older Ex's? They all have the 8.8 in a bunch of different ratios. Limited slip has been around for a long time.

 

[DocVijay]

Originally posted by OneBadExpSport
So basically I'm paying over $700 to counter what the Limited Slip Differential does? Damn technology. What differentials do the older trucks have?

Brian

No, you're not paying $700 to counter what the LS does. They each have their strong points and weak points. Let's start:

Open differential - this setup sucks. Trust me, I know as it's what I have. In this setup, if one wheel starts to slip, all the power will go to that wheel. The wheel with the traction gets nothing and just sits there. So why do they build cars like this? Cost. It's cheap.

Limited Slip differential - In this setup, the differential has clutches in it to "limit the slip." When a vehicle with an LS looses traction in one wheel, it limits how much power goes to that wheel. The wheel that still has traction gets power, so you can still move. This setup works best for road driving. When you turn on the street, the wheels must move at different speeds around the corner. The limited slips allows, as the name implies, a limited amount of slip between the clutches to allow the wheels to travel at different speeds.

Locker - this is the best setup for off-roading, but sucks the big one for on-road driving. In this setup, the wheels are locked together. They turn at exactly the same speed no matter what. Off road this is great since as long as one whel has traction, you'll keep moving. Some cars have front, center, and rear locking differentials. When all three are locked, each wheel gets 25% of the power no matter what. Great for rock climbing. Now if you are driving on the road with a locked locker, every time you turn, the wheels try to spin at different speeds, but the locker won't let them. The tires will squeal like crazy, and make drivng very unpleasant. Eventualy something may even break. That is why they are selectable. You can open them when driving on the road. But when they are not locked, they act as an open differential. Of course if you ever get stuck, just lock it and you should be OK.



So there you have it. An open diff sucks. A locker is best off road. An LS gives you the best of both worlds within reason, of course. No diff is perfect for all applications.

The PowerTrax is a newer diff. It is a locker, that "automatically" locks and unlocks for on or off road. In theory, it unlocks and allows the wheel to turn at different speeds turning on roads. In practice, it's not so clear cut. If you acceerate in a turn, it will lock. Also, some have complained because it makes a loud clicking noise when it's in "open" mode while turning.

Just choose what's best for you.

If anyone has anything to add, or if I made a greivous mistake, please add on.

 

[Robert]

OneBadExpSport - What was your stock tire size? Also, confirm your stock gear ratio (3.73?). I think 4.56 would be a perfect match for 33s. My '97 came stock with 30" tires and 4.10 axle. If I put 33s on it, I would have to regear to 4.56 to keep it as close to the stock drive ratio as possible. With the added weight from the larger tires, you are better going a little lower than stock to make up for the power loss from the heavier tires. I don't think your highway mileage would suffer with 4.56s. the difference between the 4.56 and 4.10 is only about 250 RPM assuming 2200 RPM at cruising speed. As Alec pointed out, with 2WD you should be a little lower geared to help offset the lack of low range.

 

[OneBadExpSport]

I have 33" tires now, previously 235/73/15r (29") with the 3.73 Limited Slip. It slips doing steep climbs so I won't even bother trying to make it up. I'm going to get new gears, most likely 4.56 to make up for the new tires and to get more lower rpm torque. Would anyone recommend me getting the 4.8? I'm forking over $130 for it, plus installation, so I don't want to upgrade again later.
Would the lower gear be sufficient, or should I get a an air locker as well? The ARB will cost me $800 for the locker, air compressor, and bearings. For installation, I know it's going to be a lot.

Is it a better deal to have them both done at the same time? Otherwise I'd just get the gears first and then the locker if necessary.

One final thing, when the air locker is unlocked and it functions like the open diff, how is the handling on and off road. Would I have to engage it all the time offroading?

Thanks for the help guys.

Brian

 

[Alec]

It is a MUCH better deal to get both installed in the diff at the same time. You're saving about $300 in labor charges. You could also have the differential part of the locker installed by a pro, then do the compressor, etc, installation yourself. It's just some wires and tubing, the differential is the hard part that requires professional tools and equipment.

If you're already doing gears, do a locker. You definately need a locker if you're trying to hang with 4x4s on difficult trails. To minimize cost, you could go with a different locker, I just think the selectable is your best option, and you also get the compressor for your tires (make sure the one you get can handle filling 4 33" tires in one shot in reasonable time).

With the ARB or any selectable on/off locker, on road you don't feel it. You may have tire slippage in the rain when you're onroad just like any other open diff'ed vehicle. Offroad, you'd probably want to engage it any time you're in low traction situations and your 4x4 friends either put it in 4x or 2-lo mode.

As for which gears to get, 4.56 is the safe route. If you don't travel too much on the highway and wouldn't mind 200 more rpms on the highway then go 4.88.