Hi,
Today I replaced my gearbox, and while I had it off I removed the clutch to inspect it, as I had fitted a new clutch disc ~1000 miles ago. The friction plate, pressure plate, and release bearing all appeared to be fine.
After putting the new gearbox in and putting everything back together, I went to drive the car off my ramp and found the clutch was dragging/not releasing- it took quite a lot of force to select either first or reverse, and I felt the car push in the direction of the selected gear slightly. It felt as though there was 5-6 cm of free play before the clutch began to disengage, with no pedal feel until it was right at the bottom.
So I checked underneath again, slave cylinder didn't appear to be leaking, no leaks from the clutch line, replaced the clutch fluid using a vacuum bleeder, adjusted the clutch pedal rod to the maximum length to reduce the free play, and tried again.
It felt much the same.
At this point I was out of time so drove home, and that's when things started to get confusing.
After only 5 minutes or so of driving, the clutch pedal seemed to return to a more normal feeling, and the adjustment I had made to the clutch rod meant there was very little (<2cm) free play. While driving, the gearbox seemed to feel normal, but after the 15 mile drive home I was beginning to notice a very slight whine from the gearbox.
I believe the clutch drag had mostly stopped, however I will have to try again to see if it's still dragging.
I had filled the gearbox with MTF-3 before the drive, so the oil would not have been causing any problems.
Does anyone have any experience dealing with a similar problem to this? I'm thinking it's a fault somewhere in the hydraulic system, but struggling to work out what exactly is causing the issue, and I don't particularly want to buy a new clutch master and slave cylinder unless I'm certain that will resolve the issues.
If the gearbox continues to whine/the whining gets worse, I may be contacting the seller and taking it back.
Hope someone can offer some advice!
Thanks

 

Shift lever went back in the same position it came out? Bushing are okay?

 

What kind of clutch?

 

I believe it did, I reused the lever from my previous gearbox and the bushing looks okay. When the engine is not running it feels fine going through the gears, so I don't think the shifter is the issue. Good suggestion though, thanks

 

A Spoon organic clutch disc, and I reused the OEM pressure plate and release bearing. They looked in fine condition, as the car had the clutch replaced ~15k before I bought it, so those were fine. The old friction disc was also absolutely fine, there was nothing wrong with the old clutch, I just wanted something a bit stronger to go with the lightweight flywheel, while I had the old gearbox off rebuilding it.
I believe it was on Spoons European website or possibly tegiwa, but I read that the organic clutch disc was fully compatible with the OEM pressure plate.
Really hoping this is something to do with the hydraulic system rather than the actual clutch because I really don't want to have to take the gearbox out for a third time

 

I'm feeling a disc issue. It maybe time to get the old jack stands out again.

This time go OEM.

 

Spoon is usually a safe bet.

But...I wonder why their disc doesn't have caged springs.

The caged springs are key.

The HIGH biting point usually means the hydraulics aren't the issue. But make sure the system is fully bled first. Then make sure the pedal is properly adjusted.

If none of that works...

pull the trans and check for signs that the disc spring has failed and is dragging on the flywheel or pressure plate.

 

Thanks for all the suggestions guys, I tried a few things but in the end, just driving the car for a little while seems to have sorted things out- the clutch doesn't drag when putting the car into gear, while driving I can change gear with one finger, and after adjusting the clutch rod down a little the biting point is back in a good place.
About the slight whining noise, I got one of my colleagues to drive it with me to get his opinion as he has a lot more experience working on Hondas than I do, and he told me that a small amount of noise like this one has is normal for an old S2000. If it starts getting any worse, then I'll need to investigate, but for now it's fine.

I think the cause in the end might have been the clutch friction disc sticking on the input shaft, as before I bought it the new (used) gearbox had clearly been stored outside as the input shaft and output flage both had a bit of corrosion, which I cleaned up with a wire brush and WD-40. It could be that I missed a bit on the input shaft, and it just took some use of the clutch to get it all unstuck. Worth noting that it was quite difficult to get the gearbox seated in position fully, so this theory makes sense to me.
But for now, I'm just going to continue driving and make sure everything keeps working as it should.

 

Did you use HT urea grease on the sliding points?

 

No, I didn't have any so I used some copper grease instead.