GoHashiriya

The costs are certainly heading in that direction. Hell, I already commited to financial ruin by buying a Skyline in the first place. Perhaps it was a different story as I am based in Japan. I agree with the latter remark about my mechanic not being a Nissan dealer though.

I had to keep this quiet as it's been a long-winded battle of blame between myself/my mechanic and Nengun/Nissan. But in short, I was refunded for this box. I have placed an order for a new one - prices have gone up 20% since June and there's a 3-month wait. In the meantime I'll be using this box, hopefully drive a few more events on it then swap it out in March/April. I appreciate all your opinions, it helped when talking with my mechanic. I would love to determine what has gone wrong but I'm not expecting it to be determined quickly. The OEM stuff was swapped out at about 800kms with Castrol Syntrans (TAF-X) 75w-90 GL4+, pretty sure it's fully synthetic. During the recent diagnosis I swapped it back to Nissan GL4 75w-85. You're right, it looks like p*ss.

Don't do it

Hi all, Took the car in to the shop to diagnose the gearbox noise. The mechanic was pretty sure it was the gearbox from the off, although he said the noise was much louder from the bellhousing and noted the possibility of it being the release bearing. He took the box out, tried a new release bearing to no avail, drained the oil - which looked incredibly metallic - and stated it's the box. Which is pretty much all there is to it - further opinions welcome. I took pictures and we made a video documenting our findings - yeah that tray was clean before. Video: Transmission Fluid.mp4

Hahaha, I like ‘em high, another deterrent for the thieves over here.

Here's a video I took to capture the noise. I am engaging/disengaging the clutch in the video, also attempting to do it slowly to hear the change in pitch when the transmission begins rotating. It doesn't sound promising. 660055736.120568.mp4

Cheers guys. I’ll mention this to my mechanic on Monday, luckily he performed the work which helps in the way of warranties - hopefully. I’m at the very least annoyed about the US$100 cost of the oil but given that pales in comparison to the cost of a new gbox, I’d be relieved if this doesn’t cost me another US$2k. I’ll update with our findings. I’ll also get a video clip for others to use as a sound reference.

I'll take the oil out next Monday and have a look - fingers crossed. Anybody have any experience with Nengun refunds/exchanges?

I changed the oil not so long ago and there’s been no indication of any leaks. I was under the car on Saturday and it was clean so unless it came out over the last couple of days, clung entirely to the underbody and didn’t give off any smell. I’m gonna say (pray) it’s still in there.

Hi all, just got back from the track today, after the last run I noticed a whining noise at idle, like straight cut gears but not quite so high pitch. It's pretty loud. With my foot on the clutch there is no noise and there is no noise on deceleration. I noticed it would get louder and higher pitch with engine speed until the point where engine noise drowns it out. The gearbox (30A) was installed a few thousand kms ago, it's had one oil change. I used a second-hand Nismo clutch/ lightweight flywheel kit in the install, the condition was average on installation with the clutch approximately more than half-worn. The lightweight flywheel seems to rattle a bit more as of today but maybe I'm imagining it. I would normally associate this with input shaft bearing noise, from reading other noise-related gearbox threads. But surely not, not after this amount of time? The car is going to the shop in a week for some brake work so I will ask for my mechanic's opinion then; going in with some other opinions would be helpful.

So just to update: I changed the brushes over and polished the commutator using a 1500 grit sanding sponge; it was super easy to polish being copper. A power tool wasn't necessary, although could have made it easier if you have the finesse to use it well. Yet this was to no avail, the motor worked as it did before, stop, start, stop start, etc. Today I went to my mechanic's shop to do a few things. I showed him the motor and asked in broken Japanese "who can fix this?", he took it from me and had a crack, was able to fix it-ish. From what I could understand (which is very little), the problem with the motor was with the clutch disc located amongst the gears, I saw it whilst he was working but couldn't identify any issues. I say he fixed it-ish, because now the motor will run continuously when free from the rack, which is great. But once I had reinstalled it, the tilt function would work but the sliding function sounded off, like the motor was under more load than before and the motor was struggling. We're going to pull apart the rack in the new year and see what we can find. Hopefully this is of some help to others that get sunroof motor issues with their R34, S15 Silvia, or highly unlikely the Z10 cube. I will update this when more progress is made.

Hahaha yeah, may end up launching the thing through the paper-thin walls of my dumb Japanese house. Will go at it by hand via the aforementioned method first. Brushes will arrive this weekend - hopefully they fit, as the connector comes from the rear on the new ones, as opposed to the side. From my judgement it shoudn't interfere with the spring.

Ahh, thanks both for this info. I will be paying some attention to the commutator and brushes in the coming days. I managed to order some brushes off amazon after measuring with a vernier. They might be a touch on the long side (14mm vs the 9mm OEM) but we'll see - appparently brushes can be sanded down. PLYNX, thanks for mentioning how you polished up the commutator. Fortunately I do have a drill lying around, along with a dremel that may prove handy for polishing. I'll see what's more suitable, of course I don't want to be using something too aggressive. Cheers GTSBOY, what I couldn't make out is that half of the face which contacts the commutator matches the surface curvature of the commutator, yet the other half has been worn away at an angle. See pic below. It seems that most of what is mentioned here is something I'm able to do, so I'll proceed with this for now. Looking at the windings in more detail will require a professional. Ahh, yes I see. And that's a great point. I haven't done this as the motor having two input plugs just seemed a bit daunting. - one goes to the harness and one goes to the interior switches. Perhaps it's still possible to drive the motor using an external power source and using the interior switches. For sure a switch repair is beyond me so that will require getting my head back in the old Neehongo textbook and figuring out how to converse with the electronic stall people at the market. Thanks for the responses! I'll update with how I get on with the commutator/brushes/power supply.

Hahaha, yeah I pulled it from the rack and tried operating it. It works very very intermittently, like will spin a half revolution then stop then may move again if I relentlessly press the buttons. Could be a switch that’s busted but works the same whether I’m using the tilt function or slide.

It's been a while GTSBoy, but I did heed your response. Today I found the time to pull apart the motor, after printing a bracket which holds the sunroof shut. It was fairly simple to dismantle, I took some pictures so I could remember the positioning of the gears/switches. From what I can tell, the gearing seems intact, spinning the commutator turns the gears with no resistance. The brushes, well, they're definitely there. They've worn at an angle - see pics - although, as an engineer only by degree, which was a while ago now, I don't have the XP to know how badly worn brushes need to be to cause intermittent running problems. From what I know, it's usually the brushes or switches that die. Does the wear on the brushes here say anything to you? Nope, out of stock - Nissan discontinued it around 10 years ago.

Tough one, I just use my mechanic, he's pretty helpful. His fee is 50k yen. I'm currently trying to source another car with him although not having much luck with my budget. I'm based in Nagoya so this probably isnt so helpful for you. DM me if you need more info.

Now that's what rod knock sounds like.

Or perhaps just take it back to the shop?

You mean this, right?

I'm not saying I know what it is, but to me it doesn't sound like it's knocking. When my VQ35 started knocking, the noise was more of a defined knock, where this sounds like a groan, from vibration I presume. How's your oil pressure?

Did you get a new bung? When I did mine it was pretty manky looking and wouldn't back screw-in properly. I managed to get it to seal (for now) and tighten up to about 25-30nm but I have since bought a new one with the intention of replacing it.

Thanks as always GTSBoy. I am just trying to figure out what the hypothesis is here, just in case I'm missing something. I'm going to have to wait a week or so until I can use the lift at the local shop so its good to gather a list of potential failure items. Rack bushes have been ordered. I'm going to assume the crossmember is okay but will give it a thorough check when the car is on the lift. I'll document my findings here for anyone else in the same position.

Hi all, I got an alignment today to coincide with getting the tension rods replaced and the steering pulling to the left. Initially, I thought this would just be a routine alignment to go with the tension rods being replaced; however there was something weird picked-up by the shop to explain why the car was pulling to the left. The last alignment was around three months ago and the toe was set at zero. I hit a sizeable bump in the road about 2 months ago but there was no noticeable steering issues immediately following this. Only recently, say a week or so after changing the tension rods did I notice the steering wheel was cocked to the right, even when there was contrarian camber in the road. When stationary, I can feel a slight click/knock through the steering wheel when intially turning. This was actually why I changed the tension rods, well this and leaky TR bushes. I'm sure the steering rack bushes need replacing after >200k kms but could this be the source of the problem? As you can see, there seems to be a lateral shift in something in the front that caused the toe to move to +1.6 L/-1.5 R, you'd assume somewhere in the vicinity of the rack given the movement. I'm assuming the toe was true (@ about zero) prior to this shift. Using my broken Japanese, I was able to figure out the mechanic was saying "the alignment is fine now but it will change again when subject to certain lateral forces", "something something steering rack something" - I couldnt figure out whether he was saying bush or something else here. I should note that I've recently tried (with my hands) to move the front wheels with the car in the air but it felt solid.

Hi all, I've recently been suffering from a buggered sunroof motor; it works a bit, then not, then will stay half open until I hex key it back into place. I pulled the sunroof motor from its mount and tried running it with the interior buttons and it acts the same. Now, I've been having a nightmare trying to find a replacement, it's the same unit in the S15, Z10 (cube) and R34 - Nissan discontinued it in 2013. I've searched breaker's yards in the UK, Japan, Aus and Canada to no avail. I don't want to leave it as a dud. Is it possible to have something like this repaired by an electric motor wizard of some sort? Who would you go to for something like this? Any suggestions on how to fix it would be great. I'll consider getting a plexiglass window fixed in there if I fail entirely with this.

Did you also buy your car from Trust Kikaku?