"What modifications should I do if I want to take my Frontier off road?" or "What modifications should I do first?" or some variation thereof are questions that commonly crop up on this forum. I have also seen a number of new members who were under the (mistaken) impression that they needed to put a huge lift on their truck in order to make it off road capable. With this thread, I want to try to answer some of those questions (and squash some of the myths). My eventual intention is to make this a sticky thread, but for now it is just a discussion thread - if you have any additional thoughts on what it takes to make a Frontier off road-worthy, please feel free to contribute.
First, a little background on me and my rig. I purchased my Frontier brand new in 2009 and started off roading it right off the bat - when it was completely stock. Over the years, I continually pushed my truck (and myself) to its limits, increased my skill set and became a better off road driver, and slowly upgraded the truck as the need presented itself (and as my budget allowed). At this point in time, I have taken my truck on nearly 200 trail runs.
It's not a big Frontier by any means - it's currently sitting at around 3.5-4" of lift by means of a Titan swap and runs 285/75/16 (33") tires. Despite that, it has gone places that most Frontiers only dream about - the famous Rubicon Trail in California (it did great; only needed my winch once), Steel Bender and Hell's Revenge (including Hell's Gate) in Moab, etc. and I have used it to break trail in 12" of snow with 2'+ drifts, among other things. In addition to the Titan swap and tire upgrade, my rig has a full set of armor (skid plates, sliders, aftermarket bumpers), a winch, front and rear lockers, and lower differential gearing. My build is overkill for the majority of Frontier owners.
READ THIS PARAGRAPH: For any new Frontier owner, particularly one who is relatively inexperienced with off road driving, this is what I suggest - the most important modifications are skid plates, rock sliders, and a good set of all terrain or mud terrain tires. Anything beyond that can be added in any order that you would like, but I would strongly suggest that you take your rig on a whole bunch of trail runs in a bone stock or near stock form before you spend money on anything besides those three things. Stock Frontiers can be a lot of fun and my opinion is that people should grow into their vehicle rather than spend a bunch of money on mods (that they may not actually need) right off the bat.
Having said that, here is a list of considerations if you want to take your Frontier off road. This was written with the second generation ('05+) in mind but many of these concepts can be applied to the first gen as well.
Recovery points
Recovery points should be one of the first considerations. The stock tow hook (if equipped) and stock trailer hitch (if equipped) can function as recovery points. These items can be added if the truck did not come with them. A trailer hitch helps protect the rear bumper but the trade off is that it worsens the departure angle, which is already quite poor on the Frontier.
Virtually all aftermarket bumpers come with recovery points.
Tires
This is an area where you don't want to be cheap - good tires are important for the safety of you and your family. Cheap tires can have poor traction or wear too quickly. Tires should be have an all terrain or mud terrain tread pattern and be made by a manufacturer with a good reputation (BF Goodrich, Cooper, Goodyear, Toyo, etc).
The question of whether to run all terrains or mud terrains is tricky, and it really depends on how you use your rig:
For rocks - either is fine. Mud terrains will have a slight edge, but all terrains will still perform admirably.
For mud - mud terrains, duh
For sand - all terrains
For snow - this is a bit trickier. All terrains tend to do better on hard pack, ice, and snow that is not very deep and has a hard surface underneath for the tire to bite. Mud terrains do better in deep soft snow.
For street use - all terrains will be quieter, have less of a negative impact on gas mileage, and have better traction in rain, ice and hard packed snow. If your location has mild winters, this is a personal preference.
There are also some "hybrid" tires that fall somewhere between the two, such as the Goodyear Duratrac.
Skid plates
4WD Nismos and Pro-4x's come with a set of flimsy skid plates from the factory. Other trims do not come with any skid plates except for a radiator skid. For mild trails, factory skids are generally fine. For moderate trails, consider upgrading the engine, transmission and transfer skids to aftermarket skid plates. For the gas tank, the stock skid is probably fine if your truck came with one (if it didn't, you should get one). There are steel and aluminum options for aftermarket skids. Aluminum skids are lighter but more expensive. They are suitable for most people if you want to spend the extra money. Steel skids should be purchased if you plan on doing a lot of rock crawling where the undercarriage is likely to drag.
Rock sliders
Rocker panels are a common location for body damage, since the proper technique on a rocky trail is to place the tires (rather than the undercarriage) over the largest rocks. Rock sliders are not the same as step bars. Step bars will do nothing to prevent off road damage, and in some cases will actually cause more damage to the body of the truck than if they weren't there at all. Rock sliders are designed to take abuse and will help protect the body of your truck.
Suspension
There are two considerations when choosing a suspension lift - ground clearance and suspension travel. New off roaders have a tendency to inflate the importance of raw inches of lift and minimize the significance of suspension travel (if they even understand it at all). Suspension travel is an extremely important component of a good off road build. It determines how well (or how long) the tire at each of the four corners will stay in contact with the ground when the terrain is uneven. Anytime you lift one or more tires off the ground, you have just increased the difficulty of the obstacle and the likelihood of breaking something.
Detailed discussion of various lift setups is beyond the scope of this thread, but there are a number of stickied threads in the Suspension section that can help with this. In general, the more technical the trails you plan on doing, the more money you will end up investing in suspension. Trucks that are primarily street driven but see an occasional forest service road might do just fine with a 2" spacer lift and bump stops on the UCAs, and a set of blocks or longer shackles in the rear. Rock crawlers will either want to SAS or do a Titan swap using aftermarket parts up front and upgrade the leaf springs in the rear. Most people are going to fall somewhere between these two extremes and might consider a more middle-of-the-road setup: coilovers, aftermarket UCAs and AALs, for example. Other things will need to be considered as well, such as cam bolts, longer rear shocks, and replacing or unbracketing the brake and ABS lines, so make sure you do plenty of research.
Your average Frontier does not need more than 2-3" of lift to be a capable vehicle on most moderate trails.
Mud flap delete
The mud guards that come on the Frontier are rigid and low hanging. They are prone to breakage and have a chance of damaging the body of the truck if they are dragged over a rock. Most people who are serious about off roading end up removing them (either permanently or only when running trails) or installing more flexible mud flaps. If you decide to remove yours permanently, make sure you understand your local laws (in many states, you are required to have them).
Sway bar delete
The front sway bar reduces body roll but hinders the front suspension. Removing it is beneficial for suspension travel and lets each side of your independent front suspension truly move more independently. This modification is generally only recommended if you are running stiffer-than-stock coils due to the increased body roll. Remember that this item was included on your truck as a safety feature.
The sway bar is easy to remove and reinstall, so if you aren't sure whether this mod is for you, you can take the sway bar off and drive around for a while. If you don't like the way it feels, just bolt it back up.
The second gen Frontier does not have a factory rear sway bar.
Rear diff cover or skid
If you drag the rear differential over a rock, there is the possibility of peeling back the diff cover and losing fluid. Several companies make a diff cover that is significantly stronger than stock and greatly minimizes the chances of this happening. You could also add a diff skid but be aware that this reduces your ground clearance.
Aftermarket bumpers
The approach and departure angles on a pickup truck tend to be one of its weaknesses from an off road perspective. Replacing the stock front bumper with an aftermarket one will increase your approach angle, prevent body damage, allow you to add a winch, and allow you to add extra driving lights. Installing an aftermarket rear bumper will increase your departure angle and prevent body damage.
Sometimes people can only afford to add one bumper at a time and aren't sure which to buy first. Body damage is more likely if you drag the front bumper than if you drag the rear (particularly if you have a trailer hitch installed), but the rear is more likely to drag in the first place. You can put a winch on an aftermarket front bumper but not a rear one. I can't make a recommendation either way since they both have their pros and cons; this is your decision entirely.
If you choose to retain the stock rear bumper, you may consider relocating the hitch plug. It is prone to damage in the stock location.
Lockers, gears, differentials
Lockers are a wonderful addition to an off road rig, as they will significantly increase your traction and off road performance. For mild trails, they are unnecessary. Nismos and Pro-4x's come with a factory rear locker. If you have a different trim line, an aftermarket rear locker can be added.
A front locker can be added too. For all but a small population of off roaders, a front locker is overkill. For people who like to run very technical trails, they can be a huge asset.
Lower differential gearing and/or replacing the front diff with one from a Titan (called an M205) can be considered, depending on the type of off road use that the truck will see. The half axles for a Titan diff are much easier to change on the trail than the ones on a Frontier - something to consider before investing in a front locker and/or lower gears. A detailed discussion of these mods is beyond the scope of this thread.
U bolt flip kit and rear shock mounts
If your truck will do a lot of off roading in rocky terrain, you could consider purchasing a U bolt flip kit (prevents damage to the U bolts on the rear springs if they are dragged over a rock) and/or upgrading the rear shock mounts to beefier ones. Losing a rear shock mount on the trail is not catastrophic, however - you will still be able to drive your truck home.
Driver experience and skill
I saved this for last, but I think it's actually the most important item on the list. You can spend all the money you want on building your rig, but at the end of the day, you need to know how to drive it. I heard recently that off road capability is 80% driver and 20% rig, and I don't think that's far from the truth.
If you are just starting out, learn as much as you can. Read books, browse the internet, take classes if they are offered in your area, but most of all, get out on the trail with more experienced drivers who can show you the ropes. Focus on increasing your skill set and practice using good technique (don't just mash the skinny pedal to the ground if you are having trouble - learn how to pick good lines and use good technique to get through difficult obstacles). Learn how to spot other drivers through obstacles - this will help you learn the art of choosing lines.
Please feel free to add any additional comments (or ask any questions) below.