Hello everyone,

I briefly searched the forums and didn't find anything that applied to my situation.

What happened: Driving along the interstate and shifted into 4th gear (6MT) and started to let the clutch back out and it acted like I was downshifting into 2nd (I was driving about 40mph). Really weird, never felt anything like it before. I think I shifted into 6th and everything seemed happy. I get off the interstate and the car goes dead. I go to start it up and there's a weird grinding sound and the starter is very sluggish, like it's really laboring hard to turn the engine over. It does start back up, drive a couple thousand feet and it goes dead again, wont restart this time and there's a slight burning smell now. I get the car towed home, I know there's something significant wrong with it. For curiosity I check the battery now that it's home and the battery is 12.3 volts, right where it should be. For curiosity I try to start the car again, it starts (under protest) with a grinding/rattling sound again, but it's running, I let the clutch out (shifter in neutral) and the grinding goes away, it recovers to a normal idle (it was at a low 600rpm ish labored idle) and seems perfectly happy idling with the clutch fully released and in neutral.

I believe this to be a blown throw out bearing??? Anyone had this before? Has anyone done this repair before? Are there any good videos or instructions? Do I need to be concerned about any other damage to the engine?

The car has 150,000 miles on it now, I have had some clutch slip over the past few years. Should I go ahead and replace the clutch while having everything taken apart? What clutches would y'all recommend if so?

Thanks in advance!

 

I like the Z1 Motorsports clutch/flywheel if you want to go with a lightweight option.

As for the issue, definitely sounds like something kaboomed in the bellhousing, tear it apart and see what the problem is.

Does it start easier with the shifter in NEUTRAL ? It probably kaboomed something so it's not fully disengaging the clutch and basically you're starting the engine while also partially turning the transmission because it's part engaged. Thus the hard starting, turning a lot more components.

As for the highway shift/rev when going into 4th, I can pretty much guarantee you DID moneyshift which was what caused something to kaboom. Nothing else is going to skyrocket the rpms except for moneyshifting back to 2nd.

150k on the stock clutch is extremely high, I would say most don't make it that high on a sports car and since you're already slipping it's definitely time for a full clutch job.

 

Thanks for the reply!

I am definitely planning on replacing the clutch anyway. What are the current recommendations for clutches? I have no issues with the oem, especially if it will go another 150,000 miles...but I know they are much more expensive.

So I know it sounds like I accidentally went for 2nd instead of 4th, but the rpm didn't skyrocket, tach remained pretty much stationary and it felt almost like i was pushing the brake pedal hard, plus there was a certain small grinding/vibration that was very unusual.

 

As for the clutch, if you are 100% happy with the OEM setup then you can get a LUK dual mass flywheel and an Exedy friction disc + pressure plate for an OEM replacement. If you don't mind clutch chatter the single mass units are much more cost effective plus less moveable components to wear/break in the future.

I greatly prefer the reduced rotating mass of the lightest flywheel 14 lb option from Z1 Motorsports but I don't mind a little clutch chatter AT ALL, some folks absolutely despise the chatter under 1800 rpm so the single mass is not an option. Some folks don't mind the chatter but like a little more inertia in the flywheel so the 20lb option is great for them. You need to decide exactly what YOU are looking for.

Definitely don't get a stage 2/3 clutch, you will hate the heavy pressure plate and it's absolutely unnecessary for naturally aspirated power levels.

Be sure to replace/rebuild the master and slave cylinder when replacing the clutch, they will DEFINITELY not last for the life of another clutch and when they die they can cost you a clutch so it's best to replace them at the same time.

The TO bearing needs to be removed/installed with a bearing press, it's very simple to do but if you don't have a press you will need to factor in getting that swapped. Takes about 5 minutes to press the bearing out/in so a shop should only charge you like $25 or so to do it.

The pilot bushing in the crank also needs to be replaced. A pilot bearing puller that hooks to a slide hammer is the easiest way to get it out. Most bearing pullers will be too large of diameter because Nissan uses a very small inner diameter bearing so you might have to take the bearing puller to a bench grinder to make it fit. If you need I can take a pic sometime this week when I'm at the shop of the one I modified, it's easy but necessary to replace that bushing when you replace the clutch.

Everything else is VERY straightforward for the clutch replacement, strongly recommend pulling the catalytic converters even though technically you can pull the tranny with them installed. The two forward facing bolts you remove by using about 36" worth of extensions from the top of the engine bay with a swivel at the socket end.

Flywheel bolts are a non-standard sized torx socket, 55mm with a long shaft, Z Speed Performance sells one for like $25. Don't use any loctite on the flywheel bolts, put oil on the threads to lube and torque to factory spec. There is no factory loctite so they're easy enough to remove.

There are only two options for a ring gear holder, the Kent-Moore OEM tool and a knockoff sold by Freedom Racing Tool and Auto for $175. Personally I consider it a necessary tool however if you leave the spark plugs and spin the crank until you feel compression then you CAN use a flat screwdriver up against the flywheel ring gear to hold it steady while using the torque wrench. It's a lot easier to have a second person hold the screwdriver... I understand not everyone wants to spend $175 on a specialty tool they're only going to use once, you could probably sell it when you're done though and recoup most of the cost.

When pulling the tranny there is a bolted on stack of metal weights on the left side of the tranny that makes it VERY difficult to unplug the park/neutral switch, you can reach in from the back with a set of angle head needle nose pliers to hold down the tab on the harness then fit a long flat blade screwdriver up against the harness and rotate the screwdriver to pop the harness out. Once the tranny is removed unbolt that weight plate and throw it in the trash, put the bolts back in to fill the holes. You won't feel ANY difference with 1 lb of steel removed but it's a night and day difference in the future if you ever pull the tranny again because you can easily reach the harness with it removed.

If the rpm's didn't shoot up you probably didn't moneyshift, sounds like something just kaboomed though. The OEM DMFW springs are definitely a weak point but it sounds more like you might have tossed a spring from the clutch friction disc sprung hub if the clutch doesn't feel like it's disengaging, if it DOES feel like it's disengaging but sounds terrible with the clutch pushed it you may have shat out a bearing from the TO bearing. I'm sure you'll find something obviously broken when you start pulling it apart. Strongly doubt it's something broken in the gear set, the 6MT is very stout in all it's various revisions, earlier revisions just eat sychros but other than that they're nearly as stout as the CD00A.

 

Thank you again!

This might be a stupid question, but do you always have tp replace the flywheel when replacing the clutch?
I'm not a fan of the sounds I hear from the single mass on a few videos I looked up, RockAuto has the LUK dual mass for $408. Thinking maybe I should go ahead and order it and have it ready if needed? $408 is much more believable than nearly 1k for the OEM flywheel, what in the world is with that price???

I just ordered an Exedy NKS1000 clutch kit from RockAuto (which comes with a new throw out bearing, pilot bushing, and alignment tool) and have new OEM Slave and Master cylinders coming from Z1 motorosports.

Hoping to get started pulling everything apart this weekend potentially, @cleric670 if I could get some contact info from you I would love to run a few things by you through the process if you'd be willing?

 

Yes you need to replace the flywheel when installing a new clutch. A DMFW cannot be resurfaced so it needs to be replaced.

Just send me a PM if you're u have questions, or tag me in this post, my phone will beep.

 

Another big reason for requiring the DMFW to be replaced is the balance plate springs wear out over time and the balance plate starts to slap around and sound terrible. No way to replace them, the whole assembly is riveted together.

 

Type of Manual Transmission fluid to use? Redline MT-84 GL-4 ok to use instead of the OEM stuff?

And what about the fluid for the clutch? Just anything that is DOT 4?

 

Redline MT85 works great especially with worn synchros. Anything GL4 75w-85 or 75w-90 for hot environments

 

Clutch anything DOT 3, Personally I love the Valvoline synthetic DOT 3/4 for non-racecar stuff.

Racecar stuff is sort of "Motul or GTFO" kind of thing because the clutch line is almost always going to be very hot due to proximity to the exhaust.

I would put some cheapo heat wrap on the clutch line regardless of racecar/daily driver. I cooked my fluid and lost my pedal one time when I was in daily driver trim and I wasn't even pushing it super hard, the fluid was like 6 years old though.

These cars really need to have the clutch flushed every 2-3 years.

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195k on the original clutch...I also have a sedan and the original owner was an adult. Even though I've done some mods and a tune, I don't beat on my car, may chirp the tires on the 1-2 shift a couple times a month, can't remember the last time I spun the tires off the line. Don't keep the clutch pushed in at lights either.

But I'm lucky, I'm the 2nd owner, most of these cars have been through several owners now and since you can get them cheap, younger drivers who have less experience driving a manual tear them up.

But good information in this thread for the eventual replacement I'll need someday.