Difficult to engage any gear while stopped

[cdscivic]

Hello

Recently my NSX started to have issues going into amy gear from a stop, however while moving it shifts great.

Weirdly, if I'm approaching a stop light my natural instinct puts the car into first with the last little bit of "moving" prior to stopping and that is also fine (if that makes sense, it's just how I've driven for 30 years).

The issue begins when I'm stopped and from neutral and a disengaged clutch, I engage the clutch and attempt to put into 1st. I've observed that all gears seem to present this issue, reverse included.

Car had a wavetrac LSD put in last year and has been driving / shifting great for almost a year up until recently when this new problem developed. I also recently had a new master (OEM Honda) installed as the previous one was leaking. It was professionally installed and and was definitely bled properly as it also drove fine after that service. Mileage on clutch unknown

Been reading up on the forum, I see perhaps shifter cable alignment or new clutch? Attached are pics from Aug 2023 when I had the engine out service completed with literally every maintenance part known to man kind installed.

 

[cdscivic]

*except the clutch lol

 

[Honcho]

Interesting issue. I don't think your differential is the problem. Instead, I think your clutch may not be fully disengaging. When the car is rolling, the momentum may allow the inertia to overcome the slight clamping force to permit shifting. But, when you're sitting still, you're really just relying on the force you can exert through the shift cable. The symptom sounds nearly identical to when the OEM clutch is not initialized properly. It won't shift into any gear because the clutch plates cannot fully disengage.

 

[cdscivic]

Thanks for the reply honcho!

Thinking a worn or faulty pressure plate? Perhaps the shift cable needs adjustment?

The clutch itself seems to pass visual inspection with reasonable meat left on it. I have not driven much at all since those pics, perhaps 2500 miles?

I already took it back to my mechanic once who adjusted the clutch slave, which was a reasonable first pass honestly. After that seemed fine, thinking back I suppose I could have reverted to my "shift into gear before stopping mode" since I've been doing it 30 years and just noticed on drive #2 Saturday night .

 

[TANTO]

Honcho covered you of course on the clutch - clutch dragging issue, but i would keep hitting that mechanic (or better yet find another?) as a change after parts are replaced is likely to be in the install or the parts. Many of us have done the hydraulics - it works fine and then a week or so later it needs bled again - so it might be that simple -bleeding the master cylinder is a bit tricky as you have to work the pedal by hand several times (pulling it up from the floor) during the bleed which isn't something a mechanic generally has to do often. Not to be negative for what works for you works for you -but are you saying that you shift into 1rst gear and then quickly to neutral just before you stop? I think that would cause syncro and clutch wear. Others can say what they do, but generally i think most of us just go from third or maybe second gear directly to neutral at say 10-15 mph shaking the stick left and right - just one of my many compulsions he-he. I personally wouldn't drive the car until it's fixed. Good luck

 

[comtec]

I just ordered the MC and slave yesterday. For a couple of years, if the car sits too long, I would have a weak pedal. I could pump it up and it worked fine. No leaks so I guess it's the fluid going back in the MC. Recently when I went to start, the pedal went to the floor. I pumped it and got the pedal back but couldn't shift into gear like you. Kept pumping and it finally started working. Maybe you're having a similar issue with the pressure leaking back to the MC. Next time try pumping the pedal a bunch of times to see if it helps.

 

[cdscivic]

Honcho covered you of course on the clutch - clutch dragging issue, but i would keep hitting that mechanic (or better yet find another?) as a change after parts are replaced is likely to be in the install or the parts. Many of us have done the hydraulics - it works fine and then a week or so later it needs bled again - so it might be that simple -bleeding the master cylinder is a bit tricky as you have to work the pedal by hand several times (pulling it up from the floor) during the bleed which isn't something a mechanic generally has to do often. Not to be negative for what works for you works for you -but are you saying that you shift into 1rst gear and then quickly to neutral just before you stop? I think that would cause syncro and clutch wear. Others can say what they do, but generally i think most of us just go from third or maybe second gear directly to neutral at say 10-15 mph shaking the stick left and right - just one of my many compulsions he-he. I personally wouldn't drive the car until it's fixed. Good luck

Hey tanto, thanks for the reply.

When I say I put into first, I just mean with the clutch depressed I put the gear shift to first while at the end of the stopping process and still slowly gliding to a halt. I stay in that position (clutch pedal depressed, foot on brake, gear in first) until the light changes. It's like I'm preparing to start moving again before stopping kind of.

Effectively: normal downshifts through 2nd, nearing final stopping point disengage clutch, put car in first and leave clutch disengaged.

I too occasionally do the gear shift wiggle lol.

I'll bring this up to the mechanic, I honestly don't know if it happened after the clutch master replacement due to the aforementioned driving habit (erroneously said slave above, but pretty sure that was replaced as well...will confirm).

Thanks everyone

 

[cdscivic]

I just ordered the MC and slave yesterday. For a couple of years, if the car sits too long, I would have a weak pedal. I could pump it up and it worked fine. No leaks so I guess it's the fluid going back in the MC. Recently when I went to start, the pedal went to the floor. I pumped it and got the pedal back but couldn't shift into gear like you. Kept pumping and it finally started working. Maybe you're having a similar issue with the pressure leaking back to the MC. Next time try pumping the pedal a bunch of times to see if it helps.

Will do! Thank you

 

[Old Guy]

Unlikely the cables or the shift lever mechanism because that problem would be there all the time. I kind of line up with the comments on the clutch failing to dis engage. Normally I would first point a finger at the hydraulics.

You need to confirm whether you have replaced the MC, the slave or both since you were kind of switching back and forth. Leaks out the back of the MC are easy to diagnose; however, there is a seal at the back of the MC (blue) which may be preventing the typical visible loss of fluid out the back. There are also two seals on the piston assembly (red) and the front one can be worn resulting in reduced ability to build up pressure with loss of fluid back into the reservoir and no leakage out the back. Unfortunately the clutch cylinder is full stroke so you can't do the pump the pedal test and see if the pedal then sinks to the floor like you can do with a brake MC. The clutch slave and MC get an equal amount of 'action' so if you replace one due to wear induced leakage it is probably prudent to replace the other at the same time.

I already took it back to my mechanic once who adjusted the clutch slave

I am curious about that because there is nothing to adjust on the slave unless the tech loosened the mounting bolts and wiggled it around on its mounting holes to try and eliminate any lost stroke from the piston.

My MC and slave are original (~ 80 k miles) so I have not had to bleed the system due to replacement. The car gets parked for about 5 months during the winter and I have never experienced the loss of clutch operation during storage described by others. I do flush the system regularly and I have done that with both with pressure (easy) and vacuum (kind of painful). Pressure bleeding is much much more effective at getting air out of the hydraulic system than the pedal pump method.

Weirdly, if I'm approaching a stop light my natural instinct puts the car into first with the last little bit of "moving" prior to stopping and that is also fine (if that makes sense, it's just how I've driven for 30 years).

If that means you are sitting at a traffic light with the car in gear and the clutch dis engaged, that is probably not a good thing to do. It means that the release bearing is continuously engaged while the car is stopped which can lead to faster wear on the bearing assembly. Failure of the release bearing usually starts with noise during disengagement progressing to a whole lot more noise and then failure with a no shift condition. If you are not getting any noise during disengagement the release bearing is probably OK. Release bearing or clutch fork issues might be the problem; but, I would rule out a problem with the hydraulics first.

 

[cdscivic]

Unlikely the cables or the shift lever mechanism because that problem would be there all the time. I kind of line up with the comments on the clutch failing to dis engage. Normally I would first point a finger at the hydraulics.

You have addressed the slave which kind of leaves you with the MC as the sole remaining wear item in the hydraulic circuit. Leaks out the back of the MC are easy to diagnose; however, there is a seal at the back of the MC (blue) which may be preventing visible loss of fluid. There are also two seals on the piston assembly (red) and the front one can be worn resulting in reduced ability to build up pressure. Unfortunately the clutch cylinder is full stroke so you can't do the pump the pedal test and see if the pedal then sinks to the floor like you can do with a brake MC.

View attachment 199052




I am curious about that because there is nothing to adjust on the slave unless the tech loosened the mounting bolts and wiggled it around on its mounting holes to try and eliminate any lost stroke from the piston.

My MC and slave are original (~ 80 k miles) so I have not had to bleed the system due to replacement. The car gets parked for about 5 months during the winter and I have never experienced the loss of clutch operation described by others. I do flush the system regularly and I have done that with both with pressure and vacuum (kind of painful).



If that means you are sitting at a traffic light with the car in gear and the clutch dis engaged, that is probably not a good thing to do. It means that the release bearing is continuously engaged while the car is stopped which can lead to faster wear on the bearing assembly. Failure of the release bearing usually starts with noise during disengagement progressing to a whole lot more noise and a no shift condition. Release bearing or clutch fork issues might be the problem; but, I would rule out a work clutch MC first.

I misspoke earlier, he replaced the clutch master. My apologies, I caught it later in a reply but haven't edited the original post. *Update , edited original post*

He is going to adjust the cable and rebleed the new master again. I suppose next step would be the slave? (tho I feel like it was also replaced during my engine out service).

Had not considered the wear on throw out bearing, typically my clutches on past cars have gotten 100k+, but I don't drive really hard. I will keep this in mind for future drives.

 

[Old Guy]

If it shifts fine when the car is moving I really would not go anywhere near the shift cables. You can check the cable adjustment lengths as per the service manual; but, once you have gone to all the effort of getting access to the adjusters I think the temptation is going to be too great to do something to the adjustment even if they are in spec. That is a new variable that you don't need.

If you ae uncertain about the slave, at least pull the boot back around the rod and check for wetness. If the slave has failed it should have visible leakage 'out the front'. Do you still have the clutch damper? If the slave and MC are new then the damper might be the issue. If the damper fails internally I think it should eventually fill with fluid at which point is ceases to dampen and gives you the equivalent of a damper delete. However, before that occurs it could contribute to loss of clutch action.

 

[cdscivic]

If it shifts fine when the car is moving I really would not go anywhere near the shift cables. You can check the cable adjustment lengths as per the service manual; but, once you have gone to all the effort of getting access to the adjusters I think the temptation is going to be too great to do something to the adjustment even if they are in spec. That is a new variable that you don't need.

If you ae uncertain about the slave, at least pull the boot back around the rod and check for wetness. If the slave has failed it should have visible leakage 'out the front'. Do you still have the clutch damper? If the slave and MC are new then the damper might be the issue. If the damper fails internally I think it should eventually fill with fluid at which point is ceases to dampen and gives you the equivalent of a damper delete. However, before that occurs it could contribute to loss of clutch action.

I'll get out there in the next day or so and check for both the delete and the slave condition. I had no idea this damper even existed, I'm used to all the late 90s simple Hondas like my little hatchback, old crx and integras.

I'll also inform my mechanic of your advice, thank you so much for the reply!

 

[Old Guy]

One last kick at the cat!

I had a Volvo 745 T that developed a reluctant neutral to first or reverse shift shortly after clutch replacement. Shifting in motion was OK. It was not bad when cold and got worse once the gear box warmed up. The clutch was new. The transmission and clutch was dropped a couple of times for inspection; but, ultimately we were never 100% sure what the problem was. The new release bearing spun freely on the input shaft and showed no signs of wear. As best we could figure the pilot bearing was dragging a bit which caused the transmission input shaft to rotate after the clutch was disengaged.

Our guess was that when the transmission was cold the oil drag on the input shaft prevented it from spinning making it easy to shift. Once the transmission oil got hot the oil drag was reduced allowing what ever was happening with the pilot bearing to rotate the transmission input shaft making shifting out of neutral a nightmare. We replaced the pilot bearing, greased it a lot and cleaned and lubed the input shaft and made sure that the release bearing spun freely (just because). The problem would go away and then come back. As best we could figure there might have been some kind of odd alignment issue between the transmission input shaft and the pilot bearing; but, that didn't really jive with the here and then gone nature of the problem. The best 'patch' was filling with a heavier weight gear oil.

You really need to get a visual on the release bearing; but, I am wondering if it has developed some kind of wear that when it gets disengaged it gets cocked on the input shaft allowing the clutch cover rotation to be transmitted to the input shaft when the clutch is disengaged making shifting out of neutral difficult.

 

[cdscivic]

One last kick at the cat!

I had a Volvo 745 T that developed a reluctant neutral to first or reverse shift shortly after clutch replacement. Shifting in motion was OK. It was not bad when cold and got worse once the gear box warmed up. The clutch was new. The transmission and clutch was dropped a couple of times for inspection; but, ultimately we were never 100% sure what the problem was. The new release bearing spun freely on the input shaft and showed no signs of wear. As best we could figure the pilot bearing was dragging a bit which caused the transmission input shaft to rotate after the clutch was disengaged.

Our guess was that when the transmission was cold the oil drag on the input shaft prevented it from spinning making it easy to shift. Once the transmission oil got hot the oil drag was reduced allowing what ever was happening with the pilot bearing to rotate the transmission input shaft making shifting out of neutral a nightmare. We replaced the pilot bearing, greased it a lot and cleaned and lubed the input shaft and made sure that the release bearing spun freely (just because). The problem would go away and then come back. As best we could figure there might have been some kind of odd alignment issue between the transmission input shaft and the pilot bearing; but, that didn't really jive with the here and then gone nature of the problem. The best 'patch' was filling with a heavier weight gear oil.

You really need to get a visual on the release bearing; but, I am wondering if it has developed some kind of wear that when it gets disengaged it gets cocked on the input shaft allowing the clutch cover rotation to be transmitted to the input shaft when the clutch is disengaged making shifting out of neutral difficult.

Hm, I know it seems like a lot and like I'm throwing parts at the car, but maybe I go ahead and put an sos 275 on there with new bearings anyway, this is great information sir!

 

[Old Guy]

That is your choice. Out of curiosity I checked out the Clutch Master website for details on their 8 puck design. It says the 8 puck is designed for street driven cars; but, then a little later it has this disclaimer

*Ceramic based clutch disc are not intended to increase the life expectancy of a clutch but rather to increase the holding capacity and improve the durability of the clutch. Using a ceramic based material for easy street driving may reduce the life of the clutch kit due to harsh engagement and higher tendency to slip the clutch kit. Ceramic disc are never recommended for stock or near stock vehicle applications.

If this is primarily a stock street driven car and the clutch has to come apart, I am thinking a switch to the SOS 275 might be a good choice. However, I would make sure that the hydraulics are good first because it is not for sure that you have a pilot bearing or throw out problem. If fixing the hydraulics does the trick, run the Clutch Master until it wears out or you get tired of dealing with the nasty temperament of a performance clutch and then go for the SOS 275.

 

[cdscivic]

It is absolutely a babied street driven car with an occasional pull from an on ramp. Frankly, the clutch masters is a pita to drive, but I have one on my turbo civic so I'm used to it. "Downgrading" to the sos may be in my near future regardless.

Looks like mechanic is checking hydraulics, doing the damper delete (if it's still on my car) and I am likely going sos 275.

I will update this thread as new developments happen/and the final outcome in case searches end up here as it may help future owners.

As always I REALLY genuinely appreciate the feedback and responses on prime.

 

[Honcho]

As noted previously, before tearing apart your drivetrain, both the master and slave cylinders must be confirmed working. There isn't really a way to test the slave, but the symptom you're describing almost exactly matches a slave cylinder that is on its way out (while also matching the failed initialization issue I described earlier). Most top NSX techs worldwide typically replace the slave when the master is replaced. The reason for this is, as the great LarryB once explained to me, a fresh master cylinder hooked into an old and weak slave cylinder usually causes the slave cylinder to "blow its brains out" LOL. If your mechanic is not a NSX specialist, he may not have known that. It is FAR cheaper to replace the slave cylinder (~$60) than it is to do a full clutch job! I would try that first to see if it helps.

If you do end up doing the clutch, you should consider the OEM clutch. For a street driven NSX, it's hard to beat the original. It lasts 90k+ miles and, if installed properly, is silent and easy to engage over its entire life.

 

[cdscivic]

The reason for this is, as the great LarryB once explained to me, a fresh master cylinder hooked into an old and weak slave cylinder usually causes the slave cylinder to "blow its brains out" LOL.

I have actually experienced this very thing lol. Will absolutely check and consider OEM.as.well.

Looking back at my invoices, I do not actually see a slave on there.....next up!

 

[TANTO]

Ditton OE "smooth as butta". Not to pile on, but keeping the clutch down at a light is a habit to consider breaking for so many reasons. Worn out throw-out bearings "can"wreck clutches/bellhousings/trannys in a heartbeat - although they usually howl for a very long time giving you warning. Sounds like you have experience with them but from hanging at the drag strip as a youth, when ceramic clutch linings fail/the lining material ends up in big chunks that get in the parts and well thats bad. But i am a worry wart so FWIW.