VQuick

iTrader: (17)

It seems unlikely, but the problems started soon after I went to a new car wash. Like a dumb@$$ I messed up the line-up entering the roller track thing. There was a loud clunk when I went over one of the guide bars, which was under the L side of the engine near the L front wheel. Car has a mild drop with coilovers, maybe 1.5". The car drove fine on the way home. However, about 20 minutes later as I was pulling onto my street, I noticed a squealing noise coming from the engine bay when I depressed the pedal. I parked fine, but the next time I tried to drive the car, the squealing got worse each time I depressed the clutch pedal, and I couldn't get the car in gear when I tried.

Unfortunately, at my new house I don't have off-street parking so I haven't got a good look under the car yet.

Did I screw up something in the clutch or tranny? It seems strange that it would become undriveable so suddenly, yet shift fine immediately after the incident. Maybe it was just a coincidence? Could this be a bad master or slave cylinder? Throw-out bearing?

Symptoms:
Squealing noise only when clutch is depressed
Cannot shift into any gear
No noise when clutch is out
Clutch pedal pressure/travel is normal
Clutch fluid level is normal
Gears shift fine with engine off

Thanks for any ideas or advice!

deathwobble

iTrader: (1)

Bump because im curious what this could possibly be

DennisMik

iTrader: (2)

Generally when you depress the clutch pedal and get a noise, the throw-out bearing is the culprit. But maybe somehow the slave cylinder got mis-aligned. Doing an inspection will be the only way to know for sure.

VQuick

iTrader: (17)

Thanks for the ideas. Throw-out bearing or slave cylinder are certainly possible. Anything in particular to look for to differentiate? What about a faulty pressure plate or something inside there? I realize I didn't check to see if it will go into a gear other than 1 (i.e., if it were a 1st gear synchro problem, but I doubt it given the clutch noise).

The car has 120K on it and probably the original clutch, so it may be time to replace the whole system. Anyone know offhand about the OEM replacement clutch--I remember a few years back reading that the 4th gen clutch had been superseded by the 5th gen clutch which is compatible and better.

Max_Gator

It is not your trans since everything shifts normally when the car is off.

My guess is that you have some kind of internal damage to the clutch/throwout bearing OR you dislocated some piece like the shift fork or perhaps the pinion the pushes on the shift fork when you shift.

I would start with checking the pinion that goes into the shift fork. Have someone push in the clutch while you observe the pinion. Is it bent or misaligned? Is it pushing the shift fork all of the way? Is the shift fork moving normally?

I'm picturing your "accident" as pushing the tranny and engine up, and maybe tilting it. That could cause some damage to the shift fork/pinion/throwout bearing.

Also, while you are doing that you can listen better to see where the squealing sound is coming from.

Otherwise, it is likely internal and you are going to need a new clutch.

I had a similar experience where one of the springs on my jwt clutch broke (150kish miles). I couldn't get it in gear at all when running. (No squealing either though). The stock clutch is unsprung so it is not a spring but it is possible that one or more of the prongs on the internal pressure plate broke or it is the throwout bearing.

I've done several clutch jobs and that's really all it could be. I doubt it is the slave or master since you are getting normal clutch movement and feel. Looking at the pinion in action will confirm.

VQuick

iTrader: (17)

Thanks for the help, I appreciate it! I'll have a closer look at these things later this week and will post back.

VQuick

iTrader: (17)

I checked the shift fork and it is going in and out properly with the clutch pedal. I don't see any damage under the car except to a plastic splash guard, so hopefully nothing actually was damaged at the car wash, and maybe it really was coincidence.

With the engine on, the noise is quieter now--not a squealing, just a rhythmic noise. The release/slave cylinder is super rusted externally but otherwise looks OK (DennisMik mentioned that it could be "misaligned", but I don't know how that would happen all of a sudden). I did notice today that the clutch pedal seemed a little slow to come up. It was subtle but I don't think it was my imagination. Would this be consistent with a bad slave cylinder? That looks like an easy enough job to do myself on the street, but a throwout bearing I can't do since it involves removing the tranny.

If it is the TO bearing, I will plan to buy all the parts including a new clutch and then take it to a local shop. Anybody have experience driving a car with no clutch? There are shops close by that I could drive to mostly on side streets. I could see starting the car in gear with some gas and turning off the engine at stops...kinda bad idea or very bad idea?

DennisMik

iTrader: (2)

When I said misaligned, that would cover the term "bent". But I couldn't really understand how it could get bent, but **** happens.

I have driven a car where the clutch went out. Having taken apart the Nissan starter, I don't know if it could survive. It's a pretty wimpy starter.

But driving without a clutch is all about engine speed matching when you shift. For getting the transmission out of a gear and into neutral, you don't want to be accelerating or decelerating, just sort of coasting. This reduces the pressure on the gears and the synchros so things can slide.

To shift to a higher gear, you have to lower the engine rpm while pulling lightly on the shift lever to get it into gear. If you pull too hard, you grind the gears. When the engine rpm is right, the shift lever moves and it drops into gear with hardly any grinding. If you wanted to shift into a lower gear, then you have to increase engine rpm.

Of course it is a lot easier to say than do, but it is doable. If you ever heard the term double-clutching, that is what you will be doing but without a clutch. Ask any old time, retired trucker.

VQuick

iTrader: (17)

Thanks, Dennis. I actually do have experience double clutching (and I think it's fun). Can't double-clutch without a clutch, but I know what you mean--no load on the drivetrain at the moment of shift, and rev matching RPMs. I used to pop my car into neutral without clutch all the time.

My starter has never given me trouble, which is to say it could die at any point.... Would be easy to replace with the tranny out, no? I worry more about the gear synchros than the starter.

DennisMik

iTrader: (2)

The starter is just 2 bolts and 2 wires, so I suppose the starter would be easy to remove once the tranny is out, but I've never done like that. I've always done it from the top. You remove the air filter box and it's right there.