XPLORx4

Use ATF if you have an auto, gear oil if you have a 5-speed. The reason is that if the seal between the tranny and t-case fails or leaks, the fluids won't cross-contaminate each other.

No. The t-case can be lubricated with either ATF or gear oil.

Wait a sec, do you mean you just bolted in the part shown in the photos below that was allegedly removed from an Xterra? I've been studying the parts diagrams at courtesyparts.com and the diffs don't look like they're interchangeable at all. The Xterra and R50 front diffs have different configurations. For example, the X front diff cover has a mounting bracket on it, while the R50 cover does not, and the gearsets appear to be different as well. The 02 X front diff looks like it's a 4.375:1 ratio, and certainly not an LSD. Are you sure it was from an 02-04 Xterra?

I assume he means just the diffferential carrier. The carrier will bolt up to either ring/pinion set. Sometimes it's hard to tell whether use of the word "differential" means just the carrier or the carrier plus the ring and pinion (and the housing). I must assume that the Xterra front diff which performed so well was a non-factory LSD that was upgraded by Calmini. No Xterras were factory-equipped with front LSDs. Also, if you bought the diffs from an Xterra owner who was into modding his rig, it's possible that both diffs that you got had higher-than-factory-settings for the amount of slip.

Well, you should know that the factory LSD isn't really all that spectacular. While it does provide some benefit over an open diff for on-road use, don't expect miracles from it off-highway. If you get a wheel in the air, you won't go anywhere. This short video clip shows its limited effectiveness. Here's another example of the LSD in all its glory. Unfortunately, the aftermarket really has no LSD option for this rear end. If you decide to get the LSD, you don't need the whole axle. All you need is the third member: Since the third member will probably include gears, be sure to get a set that matches your existing gears. The door sticker will say either HG43 or HG46. HG43 means 4.363:1 gears, HG46 means 4.636:1 gears. I don't know what a wrecking yard will charge nowadays for a new third member, but several years ago I picked up a set of front and rear diffs for $250 each. FYI, the rear diff from an Xterra (pre-2005 models) will also fit. If you want better assurance of putting power to more than 1 wheel per axle, especially while off-road, I would recommend you investigate installing an ARB air locker. It behaves just like an open diff, except when you engage it, so the family-hauler function wouldn't be compromised. The ARB locker can be expensive, though... about $900 for parts. I've been running a rear ARB for about 7 years now, and have had no problems with it whatsoever.

Why do you want an LSD, and what is your expectation for what it will provide to you?

Sounds like you have a lot of mechanical know-how and a well-setup shop, which is probably more than the average member on this forum. I don't know many people who can make a tool from a turned-down snowmobile piston, let alone even having a spare snowmobile piston handy!

That's pretty funny. Ask the mechanic what he did to "clean" the knock sensor. The knock sensor is basically a piezoelectric device (microphone-like sensor) attached to the top of the block that "listens" for the sounds of engine knocking. It's time-consuming to replace, since getting to it involves removing the entire upper intake system. The part itself is relatively inexpensive. FYI, I have had the knock sensor error code (P0325) for several years now, and my truck does hardly ever knocks/pings. In fact, the only time I've ever heard pinging or knocking is under heavy acceleration when I towed a boat in 105° weather after having refueled with cheap 87 octane gas. After driving for about 20 miles, I topped off with 91 octane, and the pinging disappeared. I concur with the other people who have said that knocking at idle is due to the timing belt being off by one tooth, or that possibly the timing itself (should be 15°BTDC) is too far advanced. If the mechanic insists it's the knock sensor, tell him that you will let him replace it, but if the knock still exists afterwards, you'll only pay the parts cost, not the labor cost. And if it turns out to be an incorrectly installed timing belt, you shouldn't have to pay anything at all for him to correct that mistake.

AFAIK, Xterras don't have rear disc brakes, either.

There are no existing conversion kits. The only Pathfinders that had rear disc brakes were (I think) the '95 models. Nobody has done a Pathy disc-brake swap before, so if you're the experimenting type, find a wrecked '95 with a disc brake rear axle, and bust out your tools!

Not sure where the speed sensor wire is under the dash, but if you're willing to run a wire under the truck, you can definitely get a signal at the speed sensor itself, which is attached to the right side of the transfer case.

Likely causes are loose swaybar links, worn swaybar bushings, worn or loose upper strut mount, worn ball joints, worn tie-rod ends. Without more details, it's hard to diagnose. Cheap or not, it still needs to be properly adjusted to operate properly. The TPS isn't like other sensors that are simply bolt-on-and-forget-about-it. Read the section about the TPS sensor in the link I posted earlier. BTW, the PCV valve screws into the side of the intake plenum, just behind the throttle body. Look on the top of the manifold and locate the coolant air bleed screw (should have warning sticker saying "don't remove when hot" or something like that). Immediately below that screw is a coolant line, and just to the right of the coolant line is the PCV valve.

Me too. I had a really hard landing on the front suspension in Death Valley (hit a series of whoop-de-doos, and came down hard on the up-side of a whoop). Had to replace both struts. They were slightly bent just above where they bolt to the hub assembly. The struts can't be installed backwards, but if the top mount is not aligned properly with the bottom mount, that could cause a problem. That's what I mean by "installed incorrectly." The yellow marks must aligned:

How do you know something "moves"? Lots of parts "move" when you steer and when the suspension flexes. Is there a clunk or rattle? Quite possibly, this could be the normal operation of the torque converter. However, if acceleration is constant (i.e. speed continues to rise), but the transmission keeps slipping, it could be related to #3: The TPS is located on the left side of the throttle body (Blue connector near distributor cap in this pic). It has two connectors. It may simply be out of adjustment. There are some diagnostics here that can be run to check if it's working properly. The ECT sensor and the coolant temp gauge sender are two different connections. The gauge sender has just a single blade-style connector, while the ECT sensor has its own plug. Both are located on the manifold where the upper radiator hose attaches. You should note that the sensitivity of the temp gauge sender or the gauge itself is low. That is, the needle will stay in the middle of the gauge while the ECT sensor reports between 175°F and 225°F. The gauge will start to move noticeably higher than mid-way only when the temp starts to climb above that (as observed using a Scan-Gauge II).

Camber bolts can help correct the negative camber, but it's possible that the struts are bent, or that they were installed incorrectly. It would be better to at least verify that everything's straight and installed properly before proceeding.

The heater has two parts- the fan that blows the air, and the heat exchanger (heater core) through which hot coolant from the engine passes. What is the problem? Fan blows cold air? Or fan doesn't blow?

Yes, they come with the bushings. You'll note that in the diagram, part 7 (the upper control arm) includes part 8 (the bushings), and part 9 (the lower control arm) includes part 10 (the bushings).

Those are really the only fasteners that could give you trouble, although there is a possibility that some of the 10mm nuts holding the ABS and parking brake cables to the lower links may also be bad, but you can get 10mm nuts just about anywhere, and they're not showstoppers anyway. If you don't want to spend the $$ for the fasteners, you could try inspecting them and/or loosening them slightly first to see if they really need to be replaced.

Unfortunately, they're dealer items.

It won't be an easy job. Try this link to start with. Since you live where undercarriage rust an corrosion is common, you may want to pick up a new set of nuts and bolts for the control arms, since they may be rust-welded to the bushings and may need to be cut off. Also, don't take all four links out simultaneously. It's better to do just one at a time, or it will be really hard to wrangle the axle back into place. Even with only one control arm removed, I still had to use a hand-winch to realign the axle with the bolt-holes.

It may NOT be cheaper to buy the bushings separately, have them pressed into your old control arms, and install them than it would be to simply buy new control arms with the bushings pre-installed, unless you do some of the labor yourself. You can buy polyurethane bushings for all 4 rear control arms at 4x4parts.com. They cost $36.50 per pair of bushings (so you would need to buy 4 pairs for a total of $146). And then, in addition to removing the old arms, you would have to have the old bushings pressed out and the new bushings pressed in. New lower control arms (which include the bushings) cost about $74 each and New upper control arms (bushings included) cost about $105 at AllNissanParts.org owned by Pinnacle Nissan. That's $358 in parts. So, if you can have new bushings pressed into your old arms for less than $358-$146, or $212, then you'd come out ahead. Keep in mind that if you do the labor yourself, while the control arms are removed from your truck, it's obviously not driveable. By the way, to correct the swaying problem, only the lower control arm bushings are the ones that need replacing. The upper control arms simply control axle wrap during acceleration and braking (and don't contribute to swaying), so if you're on a budget, you can postpone replacing the upper arms until a later date.

It's not the "e-brake" light, it's the "Brake" light, of which the emergency brake is only one part. A glowing "Brake" light indicates either that the emergency brake is engaged or that the brake fluid reservoir is low, due to the pads and shoes becoming more worn, or a leak in the system. Check the remaining brake pad material left, and if the pads do not need replacing yet, then add a little brake fluid to the reservoir. But closely monitor your brake pad wear so you know when it's time to replace them!

You turned the radio on, too ,right?

Do a google search for the product. Try to find reviews from unbiased web sites and user opinions, not advertising/marketing snippets distributed by the manufacturer. Still looks like snake oil to me.

Sounds bogus to me, but you're certainly more than welcome to be a guinea pig for this!