Clutch Or Transmission?

[rukus]

Hello

I've got an OS Giken twin on my car, and last year (i don't drive the car much) the clutch started making squealing and rattling sounds on top of the standard OS rattle. This whole time, the squeal/clattering sound happened at idle. If i pushed the clutch in a little bit, it'd stop, but i could still hear some light clattering. The sound was completely dependent on how much i pressed the clutch peddle. Recently, it started getting worse. The grip point on the clutch would be constantly varying randomly, ie, sometimes i could lift my foot off fully depressed by an inch, and it'd get drive, other times i'd have to lift off the pedal almost all the way and it'd then drive, but the rear end would shake and tramp.

On Monday, it started going downhill during a long drive (had to run around to clear defects!). Basically, it started randomly crunching whilst shifting. At one point i was shifting down into 2nd, and it just wouldn't go in. Then yesterday morning, i went to drive it with the plan to take it to the workshop on the way home from work, but it was totally screwed. I was reversing it out of the garage, then sitting there with the clutch in, still in reverse, about to reverse out of the driveway, when a fairly loud grinding sound started coming from the clutch/gearbox area and i couldn't get it out of reverse until i adjusted the amount of pressure i put on the clutch pedal. In this case, i lifted off a little bit and the grinding noise stopped, and it came out of reverse. Being persistent (and late to work), i thought "meh, she'll be right", and tried again, and again it started making the same noise. At this point, the thought of the car getting stuck on the way to work did cross my mind, but despite that, i said 'screw it', and lifted off the clutch a bit and it started getting drive and off i went. Reversed out of the drive way, and tried to put it into 1st - no go. Just wouldn't go in. So i gave up, neutral rolled it back into the drive way, and walked.

I've had 2 opinions given. Neither have driven or seen the car do this yet. But one says it's the gearbox, other says it's the throw bearing on the clutch. Gearbox being f*d never crossed my mind. I always thought it was to do with the clutch.

I hope my description is clear enough for you guys to provide me with some opinions?

Does driving a 32 GTR in RWD all the time have any negative effects? Reason i drive it in RWD is if i put the fuse in, it sends power to the front all the time no matter what, so i think there's something up with one of the sensors.

Also, when the car is off, it goes into every gear with ease.

Cheers

[neilsteyn01]

i had a similar problem with mine, hav a blitz twin, ripped it out today only to see one of the plates 'puck' snapped right off and must hav jammed between the friction plate and the stator. il post up pix tomorow, i would suggest taking the box out and having a look urself. if ur mechanically able to do it. otherwise send it to mechanic to do it, before it causes more damage.

all the best.

Neil

[blind_elk]

... Reason i drive it in RWD is if i put the fuse in, it sends power to the front all the time no matter what, so i think there's something up with one of the sensors.

Do you have same size tyre / rim combo on all 4 corners?

And my money is on the throwout bearing (should have been replaced when the OS giken was installed).

[rukus]

i had a similar problem with mine, hav a blitz twin, ripped it out today only to see one of the plates 'puck' snapped right off and must hav jammed between the friction plate and the stator. il post up pix tomorow, i would suggest taking the box out and having a look urself. if ur mechanically able to do it. otherwise send it to mechanic to do it, before it causes more damage.

all the best.

Neil

hmm interesting. I dont have the tools to do it myself, and i haven't had the time to take it anywhere yet. Need a mechanic that's around on the weekends!

But at the moment, it's gotten pretty bad. I tried to drive it a few days ago, just wasn't easy getting in and out of gears.

Do you have same size tyre / rim combo on all 4 corners?

Yeah i do. I used to have different wear on my fronts and rears so i thought that may have been the issue, but i got new tyres last week and it still does it

[GTRPowa]

Does driving a 32 GTR in RWD all the time have any negative effects?

No, the way they were designed was basically a standard RWD gearbox, and attaching AWD extras to it. Dunno bout the R33 and R34's (preload etc) - But yes you can run an R32 GTR in RWD all the time.

[rukus]

Just an update. Turns out it was the clutch. I have an OS giken twin (the CD version from memory), and it wasn't installed properly! So for anyone getting or planning to get an OS Giken twin, beware of dumbarse "mechanics" who don't realise the bolt sizes are different and just jam the clutch+flywheel in. My clutch and flywheel are completely destroyed now. The rivets on one of the plates had completely sheered off, and I'm told that potential disaster was imminent (ie flywheel flying out the car).

Luckily i didn't do many kms before i got it checked out, otherwise there could have been bigger damage.

so i guess: WTB new clutch+flywheel :\

ps, the work done on this car was by a 'reputable' workshop.

[Beer Baron]

yeah I was going to say it's most likely clutch destroyed, or broken clutch release fork. the flywheel bolts need to be cut down to fit an OS twin so if they were sticking out as the clutch wore down they would have been destoying the clutch pretty fast.

workshops open on the weekend include envy imports who are very cluey with these kind of problems.

my advice was to take it somewhere and get the box off as regardless of whether the problem was box or clutch you need to remove the box anyway to diagnose so no money wasted there.

if you want an OS twin I may have one here you could have fairly cheaply. it's a rebuilt one that was rebuilt at OS Giken in japan with all new friction plates and sandwhich plates, pressure plate, then they test the clamping force, reface the flywheel and bolt back together as good as new. I also have the correct height bearing and carrier to go with it too which is also very important. you must use the right length bearing carrier or things go wrong from day 1. I think it owes me about $1300 including the bearing and carrier which are about $130 on their own. it's as good as a new clutch but instead of just over $2K it's just over $1K.

If you need it let me know and I'll check if I've still got it in the house.