n00b gears/lockers question

[thrca]

Sorry if this is a total n00b question, but I'd rather get the details then order crap I don't want.

I am looking to replace the gears on my 98 TJ 4.0 and considering lockers at the same time, so this brought me to a couple questions, which are likely to open a HUGE debate.

1) With 33' ProComp Xterrains, what would be the proper gears to go to in order to get my Jeep back into its power band? I was thinking that 4.10 gears would be about right, but maybe 4.56...

2) If I were going to install lockers, would it be better to do it at the same time as the gears, keeping in mind my budget is typically spread out?

3) What lockers? I am pretty sure I would prefer to go with either a cable locker or a full locker as opposed to an air locker, but not sure what the pros and cons of each other.

4) What budgetary ranges would any different options put me into? I have some money to put in this, but am not looking to spend my kids college tuition on my Jeep.

My current off-road habits are casual off-roader/weekend warrior and this Jeep is my daily driver (although I dont drive much) so I need something that won't force my Jeep into an "Offroad primary, main road occasional" class.

Any help appreciated.

[Bratworst]

Try these http://www.ringpinion.com/Calc_RPM.aspx
and http://www.nagca.com/grandtech/geartable.htm
and http://www.nagca.com/grandtech/grandcalculators.htm

[DuffMan]

I have a 98 TJ 4.0 with 33" Kumhos.

I'm running 4.56s gears and they're a tad low. It's not my DD, so I'll trade a few (2900-ish at 70 mph) highway RPMs for better on-trail gearing. 4.10 will work as well. A buddy ran 33" MT/Rs with 4.10s fine - now with 35" Nittos he's wishing he'd gone 4.56.

I have a Detroit Locker in the rear of mine, with a Superior Super 35 kit. If yours is a Dana 35 rear axle do not lock it unless you upgrade or replace it. I've seen Dana 35s blow up with 33s in suburban subdivisions. A Detroit Truetrac is a good alternative - it's a geared limited slip, so it's locker-like, but with fewer downsides.

[Cooter]

1) 4.10s If you don't plan on going any taller with tires. IIRC, XTerrians run a little short.

2) Yes, unless you are going to run lunchbox lockers, and can do the lockers yourself. (They are very easy to install)

3) Depends- how much do you want to spend, and how do you plan to wheel, including how often? You can do an awful lot with an open diffed TJ- I used to lead events for several clubs on Pink at the Badlands completely open. You really don't need lockers as soon as most peple swap them in as much as you need experience in picking lines and feeling for traction- and open diffed rig will teach you that better than swapping in lockers.

OX had a ton of problems with their cable lockers when they first came out- I don't know how reliable thay are now, since everyone I know has sworn them off after bad experiences. IMO, an ARB would be a better chioce, but pricey.

Luchbox lockers are a pretty good choice for a budget rig, but they will take some getting used to, especially if you have a manual trans.

I personally would't bother with a Super 35- every set that I personally know of (8 sets now) has met an untimely demise. The ring gear on a D35 just doesn't allow a big enough carrier to build any strength into the differential. If you have a D35, leave it open, run a luchbox locker and take it very easy on the rear, or just swap in a D44, 8.8, or 8 3/4- the price will be close to a Super 35 anyway.


4) Lunchbox locker- $200-$250 per axle
Detroit Locker- $450-$550 per axle
Cable Locker- $650-$750 per axle
Air Locker (ARB) $650-$750 per axle + $180-220 for a compressor.



I've said this many times before, but I'll say it again- the best upgrade you can make to your vehicle's off road capability is in driver skill- and it doesn't cost much beyond time behind the wheel. (A tire with a better tread pattern would be upgrade #2)

[MuddyPaws]

Originally Posted by DuffMan

If yours is a Dana 35 rear axle do not lock it unless you upgrade or replace it. I've seen Dana 35s blow up with 33s in suburban subdivisions.

:stan3:
.....DuffMan

[Jeeperz Creeperz]

Originally Posted by thrca

Sorry if this is a total n00b question, but I'd rather get the details then order crap I don't want.

I am looking to replace the gears on my 98 TJ 4.0 and considering lockers at the same time, so this brought me to a couple questions, which are likely to open a HUGE debate.

1) With 33' ProComp Xterrains, what would be the proper gears to go to in order to get my Jeep back into its power band? I was thinking that 4.10 gears would be about right, but maybe 4.56...

2) If I were going to install lockers, would it be better to do it at the same time as the gears, keeping in mind my budget is typically spread out?

3) What lockers? I am pretty sure I would prefer to go with either a cable locker or a full locker as opposed to an air locker, but not sure what the pros and cons of each other.

4) What budgetary ranges would any different options put me into? I have some money to put in this, but am not looking to spend my kids college tuition on my Jeep.

My current off-road habits are casual off-roader/weekend warrior and this Jeep is my daily driver (although I dont drive much) so I need something that won't force my Jeep into an "Offroad primary, main road occasional" class.

Any help appreciated.

Given the above:

1) 4.10 gears. Since it's the occasional off-roader we'll make it highway happy.

2) Definitely better to install lockers at the same time if you're going to do it. Pay for it once, not twice. Also, depending on your stock gear ratio you may have to buy new carriers to support the new gear ratios. You would then replace them with the lockers (unless doing a lock-right style) and it would be money wasted.

3) That choice is up to you. Lunchbox lockers are very affordable and work well. If you have a Dana 35, you'll probably break it so you may want to consider upgrading it (although it's like polishing a turd). Detroits work but have some quirks that you'll get used to. Selectables (air or electric) are also nice.

4) Gears with full lockers are probably going to run you around $1500 (+/- depending on which lockers). Then there is installation on top of that. I'd say by the time you're all finished, you'll be in the $1700-$2000 range (again +/- depending on what exactly is done).

[sodapop]

If you decide to swap in a rear, it's not terrible on price. I put my 8.8 in the back of mine for about $500-550. New gears in that axle were pretty pricey though at $180 for the Ring and pinion and $75 for the install kit. No carrier breaks there but some ratios you have to trim some teeth or put in a notched cross pin (An addition $30 for the pin - I choose to trim a tooth) tooth grinding or the notched pin start at 4.56 gears.

My 44 front gears ran me $106 for the R&P and $75 for the install. I had to buy a new carrier which cost another $55 to my door.

If you do it yourself don't forget to budget stupid stuff in like gear lube oh and the new tools you'll have to have to set them up.

I run an aussie in my rear, open up front. I completely agree with Cooter though that you best modification or upgrade is driver ability. I wheeled a ton open before I locked it up. It totally helps you to see the best lines and learn about things like momentum and going "As fast as necessary and as slow as possible".

Next best mod in my opinion is to air the tires down - and that ones completely free (except maybe for the 50 cent refill at some stations)

[MuddyPaws]

No way he will do the installs himself. :tonka: He's a computer nerd...I mean worse than me.

And him....I really doubt he will ever break a shaft. Although if he gets deeper into it...remember, he's in the deep south...land of swamps and mud.

[thrca]

Wow, I appreciate all the great info.. I will ponder it over and add it with some more research, then show up on Tims doorstep with a trunk full of parts and a couple cases of beer. I bet he has all the tools to do this stuff. :D (Tim, I will be back in September 22, what are you doing around then?)

As for the driver ability, I appreciate the candor. While I am not extremely seasoned when it comes to jeeps, major trails, crawling, or big tires, I have spent a very fair amount of time in the mud and teaching people how to get their "stuck" vehicles unstuck. I was trained by my favorite Jedi Master of Mud, my dad. He showed me what stuck really is when you get a 20 ton bulldozer sunk into the mud past the hood.

Don't let Tim fool you, I may be a network engineer, but I am one of many hidden talents. (Like drinking WAY more Tequila Sunrises than that jerkoff Tim and still being able to fish the next morning)