Jeepernaut

Hi all,

I'm new to the forum and new to Jeeps and new to mechanic-ing. I purchased my Jeep a couple months ago and have been doing a lot of reading on different modifications. There seems to be loads of information on modifications, but I haven't found a lot of consensus on what mods are worth it and what are gimmicks. I do understand that each Jeep is somewhat of an individual and may not respond the same as another.

Some brief information on my Jeep. It's a 1997 Cherokee Sport automatic with ~195,000 on it. I bought it as is. Currently has a 4" (or 4.5") Rough Country lift and is rolling on 33 Toyo MT's. It has 4 KC HiLites on top and a Yakima roof rack. Bushwacker fender flares. Currently, I believe I have 3.55 gears, not sure what axle. I'm also pulling 11-12 mpg in town and about 15 +/- on the highway.

Some brief information on me and my use for the Jeep. I'm a senior at Oregon State and this is my first real rig. I don't have a lot of money to invest in it currently, but would like to start improving it. I can get occasional access to a shop. My current idea for it is something of a expedition hunting rig, but I need it to get places as well. I probably won't go bigger than 33's on it. I'm planning on taking the HiLites off and installing an LED light bar.

SO.... I'm looking for advice. I would like to boost my mileage if at all possible. But I also know I need more power if I'm going to add bumpers and haul much weight behind it on hunting trips. Currently, the way I see it as far as initial investments, I can either re-gear up to 4.10/4.56 or something, or I can install a bunch of mods (CAI, 62mm throttle body, new header, injectors, exhaust system) and come out to roughly the same cost.

What do you all recommend? I'm sure I'll have more questions as I go. Regearing is something I have not figured out at all yet.

Thanks for any help/advice you may have!

Ben

TL;DR: New to the Jeep world, looking for better mileage and performance. Don't know where to start.

jay_sco

Find out what rear axle it has, and when's the last time a complete tune up has been done.

DirtyKK

Welcome!

If I was daily driving my XJ the first mod would be gears for sure. Then slowly work on all the small, cheaper supporting mods.

I do not have gears yet but I regeared another vehicle and gained 2.5 mpgs just going back to stock tire/gear ratio. If I were to do it again I would go one step lower gearing for better low end power with the added weight of wheels/tires and gear.

My cherokee had an aftermarket muffler when I bought it so Im not sure how much it helped. I religiously check my mileage at every fill up. With 3.55s and heavy 15x10 steel rims and 33x12.5 buckshot mud tires I get 16 mpgs with the 80-85% of my travel speed being 55-60. Not bad for this old pig and she leaks/burns a quart of oil every 2-3 fill ups. Ridiculous, I know, I'm working on it.


Fuel injector swap netted me .5 mpg
plugs, o2 sensor, pcv valves netted .5 mpg
snorkel gained 1 mpg

Keep the HiLites and put the LED light bar money to better use. How often are you using them lights? You just want the LED bar for the cool factor, we know.

Raise all drivetrain breathers
Recovery Points/Gear
Skids/Armor

Upgrade as things break or need replaced.

READ! Here---> http://www.jeep-xj.info/

Dang I know that's long! Hope it helps!

PNWjeeper

Most likely have an 8.25 rear if PO knew much about jeeps but it could have the Dana 35. Based off the chart I'm about to post it can be difficult to tell the difference between the two, however the Dana 35 looks like an elongated circle, where the 8.25 will have be flat on the top and bottom with obvious edges. If you're still not sure post a pic.

Jrozar

Change your neutral safety switch, cops and my other sensor that could fail from being old.

WyoCherokee

Lets not jump to throwing money at things that done need replaced.

First off: Do you have a Check engine light, If no, then a simple tune up and oil change is all you should do. Pull your spark plugs and put Champion Coppers in there. These 4.0's can be real finiky with the newer iridium plugs. Second, New plug wires, cap and rotor.

Next: most folks will do the 784 fuel injector upgrade. these are the 4 hole injectors providing better spray pattern. Check the for sale section on here. I snagged mine for $80 rebuilt and tested.

Exhaust:
Go for a 2.5" system if you can afford it. Most shops can make you a down pipe and you can piece together a system to your liking

Following:
the Homebrew cowle intake is cheap and offers good sheltered cold air.

Putco Headlight harness and H4 housing upgrade

Being in Corvallis, im sure you have lots of farmer buddies with welders who can make you bumpers or you can order the DIY bumper kits online and just weld em together. (I grew up in Oakland just down the highway)

Buy a HiLift Jack! It will save you more than you think.

Oregon Mud Sucks! Buy a winch. I love my Smittybilt.

A good CB is well worth your purchase.

Theres a good starting list for you. From there you can dive in to the world of suspension, bumpstopping, lockers, disc brake swap. etc.

DirtyKK

I would like to politely disagree with this. The majority of the time the OEM sensors are far better then the cheap Chinese ones at the auto parts stores. If it isn't broke, don't fix it.

Jamie57

The very first thing you should do after changing all the fluids and a tune up SHOULD be making sure your braking system is in good order.
All the go fast shiny bling crap means NOTHING if you can't stop in an emergency!
After that comes fixing the dismal lighting that come on our XJs.
Do yourself a real favour here and put in the Putco or whoever's wiring harness upgrade. Even with stock headlight your going to see AT LEAST 30% better at night. I also added the Hella H4 headlight system but that's just me.
After you feel much better about being able to stop and to see at night and be seen you can start adding all the fun stuff we like to add to our money pits.

denverd1

Never understood the obsession with mpg's on lifted rigs. you want an economical car, get something else. that said, if you want to get you mpg's back, regear. keep in mind you're going to spend close to $2K to get that done. maybe buy a honda accord for your commute?

brakes are good. give them a once over
steering is important. make sure your TRE's are in good shape

other than that, you need to define the jeeps purpose before you get crazy with stuff. daily driver with the occasional weekend offroad trip? rocks? mud? keeping fat chicks out?

tires you run will depend on gearing you pick
staying at 4.5"? going higher gets expensive quick

Fred/N0AZZ

When all small things are done I will tell you the single improvement that gave me the most bang for the buck of all in over $10k in parts at that time were new gears and lockers, hands down.


That was running a 33x12:50x15 (now running on 35's also) going from 3.55's to 4.56's and my XJ is heavy lots of weight in options and gear carried. With the 3.55's on mostly level highways the trans would up/down shift all the time in a slight breeze and trans ran hot to boot. MPG's ran around 11-13 avg. after gear swap gained about 5mpg avg. with no up/down shifts like before with avg. temps.


Off road with the gears and lockers compared to the open differentials before a whole new world opened. I could go places in 2wd on trails where before that only were passable in 4wd with tire spin at times. In 4wd Low it was a real beast very slow and easy in difficult areas with very little slippage both differentials locked.


I only wished that I had done this sooner rather than later for what it achieved in my XJ. But "Don't" ignore all the basic items first but this would be one of my first major upgrades from experience.

gunmetal_nightrider

^that. Lots of experience there. After learning some things myself and reading of others' mistakes: get yourself a properly tuned up and maintained xj before doing all the popular "mods".

You will get props for doing things the right way.

New ujoints all around (axle ujoint and seals too), brake service, transmission flush, oil/fuel sysetem filters, serpentine belt, coolant/heater core flush, throttle body cleaned, vacum system check, engine/tranny mount check, control arm bushings check....off the top of my head.

All of those things seem to be the most frequently found issues folks talk about (besides electrical gremlins). These things can make a fun day bad so haviny a strong setup before you "mod" is very helpful in avoiding a bad day

thebyus

Get yourself an OBDII scanner (http://goo.gl/D2Hrxg). Best $20 you'll spend!

s346k

i don't understand this. I've put over 70k miles on my jeep and never needed a cheap scanner.

Hoosier8

First 'mod' for me is taking care of any and all rust. Once it starts, it can develop fast.

Jeepernaut

Wow, thanks for all the replies! I'll try to address each one, also so I can keep it organized for my own sake.

First, my purpose for the Jeep is something of a expedition hunting rig. I know that I'm not going to get a 20mpg vehicle out of it, but because it is my daily driver and will be for a while, I would like to do what I can for some improvement. Not only for my wallet, but only getting 210 miles out of a tank is inconvenient to say the least.

Once I graduate in the spring, it will be seeing a lot more dirt. Next fall I have a big plan to make a loop through Wyoming, South Dakota, Montana, and Idaho and hunting in each state. I want to be best prepared for that. I will likely be hauling a small trailer with a propane chest freezer on it and other gear. I feel like I need more power. Currently, if I'm in OD a strong headwind will make the sucker really work. Tend to run it in the 3/4 spot.

I believe my front axle is a Dana 30, and based on the photo, it looks like my rear is an 8.25. I plan on staying at 4.5" and keeping the 33's. The light bar can wait, but it is awfully handy for twisted mountain roads and spotlighting jack rabbits.

Brakes are in excellent shape, fluids recently changed, sea-foamed it.

I am currently working with my uncle on designing a front winch bumper and a rear, swing-out tire carrier with spots for Jerry cans and a handy-man.

It seems like so far the consensus is preventative maintenance, then tune up, then re-gear? Again, I'm trying to find a balance between enough power, cost, and mpgs. MPG's are ultimately less important, but I can't afford any worse.

What is meant by a basic or full tune up? Is that something that I can do or is it best done by a mechanic? I can research how to do the stuff, once I know what needs to be done. What is the result of a full tune-up?

Re-gearing could probably use it's own thread, but... What am I going to gain from re-gearing? How do I know what gears to get? Is it most economical to get an axle with the gears already in them? If I do regear, is that the time to put lockers in as well?

Sorry for the newb questions, trying to learn! Thanks for again for the help.