clutch or crank shaft

[Michael Drake]

Hello, my names Mike and I own a 1991 red NSX Reg H7NSX I bought my car from Honda Chiswick just over two years ago with about 50000 miles on the clock, I drive it every day apart from when its back with Honda getting bits fixed, It's taken me two years to get everything just about perfect but I have never been happy with the clutch, the car has been back to Honda at least 6 times for them to check the clutch and make adjustments. Even on the test drive I complained that the clutch wasn't up to scratch but they showed me paper work confirming that they had replaced the clutch themselves just one year before. Anyway, they eventually agreed to put an other clutch in ( I paid about half the norm ) it's better but still not right as far as I'm concerned , feels like and sounds like the clutch is slipping if I'm on a slight incline. Now they say that it could be the crank shaft which I think is attached to the clutch, they it has a little play. Is this a big deal ?? expensive to repair?? I live in Loughton Essex any one had a similar problem?? Thanks in advance. Mike

[markc]

Hi Micheal,

It's not easy to diagnose from a short discription of the problem but I'll have a stab.

You say it "feels like and sounds like the clutch is slipping if I'm on a slight incline...", could you be more precise? Does it do it in all gears? Do you have to be hard on the gas or does it do it on any incline with any throttle opening?

You usually start to become aware of a clutch starting to slip when you put your foot down on steady/steep inclines when in a high gear ie 4th/5th. The engine revs will start to increase (flare) but the car does not accelerate. Watch the speedo and rev counter when you next experience the problem.

Is the noise you describe the engine gaining revs or some other noise? Could you try and describe the noise, is it a rattle, a grate, a whine etc.

How does the clutch peddle feel? Where is the biting point? Does the peddle ever feel differant or the biting point change, when hot for example?

You say that Norton Way have said it could be the crankshaft. Unlikely to the the crankshaft itself but it they could mean the crankshaft pulley, or harminic balencer in NSX speak. This is at the other end of the engine (Clutch/Flywheel at the gearbox end, crankshaft pulley the other) and is rubber mounted. The rubber is there to help smooth out general running but the rubber mounting can break up. If it fails completely the results can be catastophic, ie jumped timing belt and bent valves! There's a good thread on NSX prime that explains and discusses the problem... http://www.nsxprime.com/forums/showthread.php?t=75746&highlight=crankshaft

I'd ask them to explain what they mean by "crankshaft" and get them to check this first.

I can't see how it would be the crankshft itself but if it is is an engine out and a complete bottom end rebuild which is a very big deal and very expensive.

Cheers

Mark

[AR]

Are you sure they might not mean the "mainshaft" as in the gearbox main shaft???

[markc]

Are you sure they might not mean the "mainshaft" as in the gearbox main shaft???

Michael, you should also ask them to check if your car has one of the transmissions affected by the infamous "Snap ring" issue. It applies to certain 1991 and 1992 cars.

Your description of the problem doesn't really match those of a snap ring failure (see article linked below) but it's worth checking.

See here for details... http://www.nsxprime.com/wiki/Transmission#.22Snap_Ring.22_Failure

Let us know how you get on.

Cheers

Mark

[cas]

Hi If the clutch is slipping the car won't accelerate quickly so if you have'nt noticed a change in performance it is notvery likely. Sometimes the clutch can sound as if it is slipping but realy it is the alternator belt which is loose. I recommend you do a quick check press the belt with your thumb to see if is nice and hard. good luck

[Michael Drake]

Thanks Mark,
The acceleration is ok, can't feel anything wrong during acceleration. The problem is in first , feels necessary the raise the revs , not excessively though, you then have the sensation that the clutch isn't holding as it should and a sound as if the fan belt is slipping although it isn't, clutch pedal feels ok but the whole thing doesn't feel sure.The car is with Honda at the moment because the traction control and anti lock brake lights keep coming on so will ask them to explain in open language exactly what they meant when they say the crank shaft. Thanks Mike