Clutch Confusion...

[Two Fowty]

Ever since I bought my car, the clutch has grinded when downshifting into 2nd (after the car is warmed up, before its warmed up it doesn't grind). It doesn't grind, however, when I downshift below 15mph at idle rpms. Not really a big deal, except having to slow down that slow just to downshift. Yesterday, replaced my throw out bearing, got a look at my clutch, and it has very minimal wear, which is good. After I got the throwout bearing in, I still have the same problem.

Today, once, I tacked my rpms to like 4500, dropped clutch, spun tires, tried to shift at 5500 into 2nd, grinds, cant even get it in gear. (i used to be able to, with grinding, but it'd actually go into gear) this time, it wouldnt go in at all, just horrible grinding. By the way, I have a stage 5 clutch.

So, pretty much, this point of this thread is to find out what is going on. I'm not too knowledged about clutches. I've read abit. Only thing I would think it is, is synchros, then again, I'm not too sure how those work too. I've tried letting my rpms completely drop, and then gently put it in 2nd (above 15mph) but it still grinds, which makes me think it's my synchros. But why can't I shift into 2nd like that anymore? I'm coming here to ask cause maybe someone else has had person experience with it.

[Sentientbydesign]

Technically your clutch isn't grinding. Most likely it's the dog gears.

I would say you need to check your clutch oil as well as the pedal for proper engagement/disengagement. If this is only happening at warm temperatures, I'd say the fluid/oil is boiling and not providing proper clutch disengagement making the synchros over work.

You also have an aging vehicle. If the synchros are the originals (very likely), they are probably going out.

[steve s14]

If it's just grinding in second, it's probably the syncro for that gear is shot.

[Two Fowty]

Technically your clutch isn't grinding. Most likely it's the dog gears.

Could you explain that.

I would say you need to check your clutch oil as well as the pedal for proper engagement/disengagement. If this is only happening at warm temperatures, I'd say the fluid/oil is boiling and not providing proper clutch disengagement making the synchros over work.

what causes boiling? is that normal? and how do i know if my pedal is engaging properly or improperly? how do i stop boiling? sorry for the questions, just learning here..

[Sentientbydesign]

Your clutch is a friction disc. It doesn't grind. Period.

Your clutch was designed to rub against the flywheel, so it doesn't grind. Usually that's referred to as "feathering" when you allow the clutch to slip.

Dog gears are the gears that engage and disengage when you shift. I common misconception is that the actualy input/output gears are the ones that engage/disengage. There are a second set of gears that engage/disengage -dog gears. The syncros and the dog gears are usually attached in some manner. Syncro syncronizes the input/output gear speeds, then allows the dog gears to engage.

As for the boiling clutch fluid. This can be from contamination, or the fact that your poor old master/slave cylinder is having to deal with increased pressure due to that damned "stage 5" clutch. BTW, I hate "Stage x" as a designation. It means NOTHING except when compared with other "stages" from the same manufacturer. There are no specs that detail what a "stage" entails.

Get the clutch fluid changed to see if that fixes things. I'm sure that the engagement/disengagement pedal adjustment is in an FAQ around here somewhere.

[Two Fowty]

gotcha, that does help a bit.. and my clutch is a clutchmasters stage 5 racing clutch.. with instant engagement.

would you recommend replacing my slave cylinder with a brand new one? or should i try upgrading it, not even sure if i can.

[moulton712]

no way can i see your clutch fluid boiling, if your motor is stock and have stock lines. it's it's own closed system.

on the other hand change your transmission fluid and/or top it off. check for metal shavings. metal shavings... your syncros are probably smoked and your second gear is probably not so good off. if no shavings and transmission fluid is good than bleed your clutch line. if nothing prior to this works, lastly adjust your clutch pedal. lastly get a new transmission. done.

[Sentientbydesign]

no way can i see your clutch fluid boiling, if your motor is stock and have stock lines. it's it's own closed system.

on the other hand change your transmission fluid and/or top it off. check for metal shavings. metal shavings... your syncros are probably smoked and your second gear is probably not so good off. if no shavings and transmission fluid is good than bleed your clutch line. if nothing prior to this works, lastly adjust your clutch pedal. lastly get a new transmission. done.

My G's fluid deteriorates and "boils" and my engine is basically stock and I have a MUCH more conservative pressure plate than the OP.

Fluid contamination (more common than I thought) lowers the boiling point of the fluid as does water absorbtion or cheap fluid.