Slartibartfast

Try the HA section in the service manual. Free download from Nicoclub and worth having anyway. I had a look at the '97 manual (because that's what's on my hard drive) and there's a bit about the cables on HA-52. There's a lot of troubleshooting in there, most of it electrical/aircon related, but there is a section for the manual HVAC. The vent direction sounds like something's mechanically busted. Hopefully the head unit, or the cable's come off, though the tight spot could be something that's fallen down a defrost vent and bound up the mechanism. If nothing jumps out at you, I'd remove the cable from the HVAC head and see if pushing and pulling the cable manually makes the vents work. If it does, it's the head. If it doesn't, either it's come off the blend door, or the blend door is buggered. The temp is an odd one. Again, hopefully a fault in the head/cable and not a blend door. There's a valve that's supposed to shut off the coolant to the heater core when it's set to fresh air, doesn't sound like that's working.

Looks like the seller got what he wanted for it!

Again, I don't know crap about the R52, but from what I've read they "judder" before they let go. Probably a good call selling it before that goes--I have not heard good things about Nissan's CVTs. Recently I helped replace the rear wheel bearings in a friend's Honda. The howling noise went away, but now that one noise is gone, we can hear all the other stuff that's worn out.

Unless it's easy to get to, or you have a good reason not to trust the old one, or you're in there for something else anyway, I'd probably leave it on the shelf.

Based on the cartoon in the manual, I still think it's dragging the clutch to transmit only as much torque as it thinks it needs to. Think of it like brakes--they're not just on or off. Slipping a clutch like that does seem a little abusive, but automatic transmissions slip a little whenever they grab a gear (or they'd slam you around), and the clutches in a limited slip diff are slipping any time you're not going dead straight. They're built to take it, and also they're not slipping all that fast, or for all that long. In normal operation, I would not expect the transfer case clutch to have to slip all that much, either. If the system kicks in quick enough in response to wheel slip, there won't be that much speed difference to correct for, and the slippage when cornering shouldn't be much either (similar to how it's not enough to activate the viscous coupling). Driving down the road with mismatched tires may be a different story, if the transfer gets confused and drags the clutch for miles on end trying to correct what it would see as wheel slip. Hopefully the same code that makes the computer pissy about manual hubs would catch on to what was happening and release the clutch before it burned itself out--or the operator would know enough to not leave it in auto mode when running an undersized spare. I imagine the computer is pulse width modulating the solenoid (cycling it on and off faster than the clutch can react to, while varying the length of the 'on' pulses) to dial in whatever pressure it wants. (IIRC this is also how the automatic transmission controls its line pressure.) If it was just stabbing the clutch to full lock, letting off to see if that fixed the slip condition, then stabbing it again if it didn't, I would expect the truck to shudder like the ABS was kicking in. I have no personal experience with this box, so I'm mostly speculating here--as are the people in the thread you linked. If you want to take a deep drive into how this critter operates, the TF section in the service manual is your best and probably only source of accurate information, short of dissecting yours to see what makes it tick, or datalogging the solenoid in action. My old TX10A may be clunky and primitive, but it sure is easier to understand!

3mm. I think I'm using these ones.

Wet clutches are controllable, viscous couplings are not. Viscous couplings are just a stack of plates with thick oil between them that makes it hard for them to move one independent of the other. Half of the plates go to the input, half to the output, alternating, so when the coupling is forced to slip, all the oil across all the surface area of each of the plates (except the two on the ends) fights it. The wiki writeup on them says the oil gets thicker the more it heats up, so the more you beat on it and force it to slip, the harder it fights back. It's got enough slip to avoid torque bind, but it fights back enough to put power down when you need it. It has no external controls. A wet clutch is more like the clutch in a manual transmission vehicle (except that it's soaked with oil). An external force (in this case fluid pressure on a piston, supplied by the pumps, controlled by the computer) clamps the plates together, causing friction between them. Clamp them hard enough and they don't slip at all. It's the same tech that grabs gears in automatic transmissions, and I think it's common in motorbikes and quads, too. Usually they've got a bunch of plates, like the multiplate clutches used in some sports cars, though the exploded diagram for the ATX14A shows a smaller number of plates than I would've expected. Technically the wet clutch could slip when clamped completely up, same as a dry clutch, but I imagine you'd have to hit it pretty damn hard to break the static friction unless it was wore slap out or you were hitting it with way more power than it was designed to take. AFAIK auto mode won't lock the clutch completely, so no, it shouldn't torque-bind if you're gassing it through a corner. The viscous is a far simpler solution, but I imagine it did not play well with the ABS/traction control, or Nissan didn't like its road manners (might be more prone to understeer). The computer-controlled-clutch solution meant they could make it behave however they wanted. I've seen similar computer-controlled wet-clutch transfers in domestics of the same era (BW4405 in an Exploder, NP236 in an S10 Blazer), so it wasn't just a Nissan thing. That is a lot for a filter. If you haven't, google the Nissan part #--if that quote came from a dealer, you may find it cheaper online. If it's like the filter for the trans, it may be more of a screen than a filter, and easy enough to clean out. Worst case, I imagine the transfer case would have to be absolutely shredded to shed enough material to clog the filter. New fluid is a good idea, though. Did a world of good for the TX10A in my '95. Make sure you get the right stuff!

There is no center diff or viscous anything. The ATX14A is a part-time transfer case, so the rear output is always driven directly (1:1 off the transmission, or 2.596:1 in low range). The front output is coupled to the rear output using a wet clutch, like you'd find in an automatic transmission. The clutch is controlled by a computer. In 4H or 4L, the clutch engages fully, locking the front driveshaft to the same speed as the rear one--which is fine off-road, but usually not what you want on pavement. In auto mode, the computer feathers the clutch as needed, squeezing it together harder the more the rear wheels are slipping, the harder you're accelerating, or the more you're engine braking. TF-45 of the service manual has a cartoon explanation of this. Because there is no center diff, there is no risk of all the motion going to one wheel (unless you're in 2H)--but no center diff is also why you get torque bind on grippy surfaces in 4x (also, why you shouldn't drive on grippy surfaces in 4x). This is why auto mode exists. It only grabs the clutch as hard as it has to to keep you going, so you can drive it on dry pavement without torque bind, but if you do find a slick spot, the front end will still pull you through. Basically, they added an all-wheel-drive setting to a part-time transfer case, and all it cost them was one more computer, two hydraulic pumps, and five times as many pages in the service manual. Seriously, the TX10A takes up 30 pages, and the ATX14A takes up 154. It's a neat piece of kit, but good lord is it complicated. They do seem pretty reliable, though, and I'm told the auto mode is nice in patchy snow.

I would be surprised if there are a whole lot of options there. Rockauto lists Zumbrota RTC59276 (reman), but naturally it's out of stock. The part number might turn one up elsewhere, though.

It's not just semis! I haven't had enough rear axles apart to say for sure, but I suspect our greased bearings are more the exception than the rule, at least on older stuff. That Park greaser looks like a great way to go. Much easier to maneuver.

Some axles don't have greased bearings--the bearings are lubed by gear oil by design. I'd be surprised if the rubber in a grease/oil seal could handle one but not the other. I bought a press when I did my rear bearings, and ended up having to make a spline nut wrench and some press tooling from scratch. There's usually a workaround, but I don't blame you for not wanting to break it down more than you have to. Hopefully the grease isn't too washed out and you can just shoot some in. I think I've seen a grease gun adapter that's basically just a zerk and a needle--one of those might let you get into the bearing better. And yeah, no sense dropping the diff if you can avoid it! It's a big awkward chungus of a thing. A friend of mine did the seals on the front diff in his S10 with the diff in place, though those were not nearly as complicated.

Weird. Hopefully it stays fixed!

If gear oil is leaking from between the extension tube retainer and the tube, then yeah, sounds like it's just the inner seal that's gone, and the bearing might still have grease in it. If gear oil is coming out of the grease seal, that suggests the grease seal is bad too--and the oil had to go through the bearing to get there, so the grease is contaminated/washed out. If the grease is gone, then the only thing keeping the bearing alive is the oil leaking into it, which new inner seals will cut off. Unless you can clean and regrease the bearing in place, and you trust the outer seal to hold that grease, I'd say go for the whole meal deal here so you only have to drop the diff once. A cold chisel is just a stout blunt chisel, as opposed to the sharp chisels used in woodworking. A screwdriver would probably work, depending on what the collar is made from. You're not beating on a bearing or sealing surface, so I wouldn't worry if you scuff it. So long as the shaft is well supported below where you're hammering so you're not trying to bend it, and you don't go after it with a grinder or an air chisel or something, I think you would struggle to hurt it.

Unplug the blower motor and see if you have 12v at the connector when the fan is supposed to be on. If the blower motor has power, but doesn't go, it's probably dead. If not, then start digging around in the service manual (free download here) to find which fuses/relays/etc you're after. You want the HA section. Hopefully it's something simple and not an issue with the HVAC head.

Usual disclaimer, I haven't had an R200A apart. But I had a look at the manual, and here's how I think it goes. The first time, you're removing the long-side axle shaft, the bearing, and the flange that holds the bearing (labelled "extension tube retainer" on PD-18) all together. While it's out, you cut the collar which (I'm guessing) holds the bearing in place on the axle shaft. Then you bolt the extension tube retainer back to the axle tube to hold it (and the bearing) while you draw the axle out of the bearing with the slide hammer. I don't know why they have you bolt it back up rather than using a bearing splitter and a press. It could be that it comes out easily enough with the slide hammer that setting up the press would be an unnecessary hassle, or maybe they thought the extension tube retainer might break if it wasn't bolted down in four places while it got yanked on.

It's clean, and people on BaT pay silly money for clean. This one made it past 20k. I imagine the seller will do well on it.

That is weird. If messing with the cluster brings it back for a while, I would dig into the cluster again, maybe check/reflow a few solder joints. I wouldn't expect a damaged gear to falter and drop back out like that. I would say low signal strength on the sensor, except that messing with the cluster wouldn't have brought that back.

I don't know crap about the R52, and I'm not entirely sure what a faint turning sound is. If it seems to be coming from one corner of the car, I would check the wheel bearings. If it's eaten one diff already, might be good to check the level and condition of the fluid while you're at it, make sure it hasn't done it again.

You misunderstand me. Even if I had the money, I could not bring myself to spend that much of it for something that I could make in a weekend, for a fraction of the cost, in a way that would suit my needs better. If you're happy with your purchase, good for you.

From what I've read, the rear of the Patrol is 33-spline, and the front is 31-spline. The 33-spline H233B is also used in the R50, but AFAIK the only ratchet locker for the 33-spline was made in Russia, so you may have a hard time tracking one down. As for the H233 guts fitting the R230, I have no idea. If anyone knows, it's @hawairish.

The wheel bearings will work without the axles, but the axles seal the back side of the wheel bearing to hold the grease in, so I wouldn't leave it like that for long. Probably fine for a test drive, though. The VDC/traction control system was the difference between the two systems I mentioned earlier. I do not remember which was which, just that it was backwards of how I expected it to be.

There's nothing wrong with paying big money for pre-built stuff, if you can afford it. Some of us can't.

TrakMotive sounds familiar, might've been that one. Didn't know they were $350 each! I haven't heard of CVs vibrating, but if it's not the driveshaft or the tires, I don't know what else it would be. How high is your lift? I've heard of R50s lifted too far without a subframe drop having CV issues.

Pretty sure it's the fronts you're after, though I've read about using them on the WD21, not the R50. But don't take my word for it, I'm still at stock height.

EL-91 of the '97 manual has troubleshooting info for the speed sensor and its wiring. The speed-related intermittent thing is weird. Sounds mechanical, like maybe the gear on the sensor is missing a couple of teeth and if it stops in the wrong spot, it takes some time/vibration to catch and turn again? If all of that checks out, I'd be tempted to loosen and retighten the screws on the back of the cluster, on the off chance (assuming the R50 cluster is built like the WD21 cluster), though this doesn't sound like the usual loose connection. Looks like the speed sensor is wired to the cluster, which then passes info along to the computer, for whatever that's worth. Interesting that the speedo's in and out, but the computer hasn't decided it cares enough to code yet. I guess it doesn't need that info for much (yours is manual, right?), so it may not be looking for that info often enough to notice when it's not there.