hard shifting all of a sudden, particularly when cold

irish44j · 10-17-2018, 07:50 PM

So background - when I put this car (back) together about a year ago (maybe 2000 miles ago), put in a new (OEM-style) clutch, new TOB, new pivot bearings on the clutch arm, etc etc. Also put in new clutch master and slave cylinders, but at the time not knowing I admittedly (I think) got Uro stuff, which I've since learned is perhaps not that great for these cars (though never had any problems with that brand in various e30s).

Also got all the only944 linkage stuff.

Anyhow, after all that the car shifted awesome. Extremely smooth, no noises, no stiffness when cold, literally perfect.

Fast forward to a month or two ago, I was coming back from a long-ish day trip up in the W.Virginia mountains. At one point running in 4th, I came around a corner into a steep uphill and downshifted to 3rd quicker than these cars like, including a pretty forceful clutch kick. Yeah, I usually drive a WRX or e30, which shift quickly.

Anyhow, nothign really happened then, but a few miles down the road I was suddenly unable to shift gears. I clutched in and kind of coasted in neutral for a minute, and then was able to get back into gear. I proceeded driving home and while the shifting seemed notchier, I was able to shift.

Since then, the car has been really hard to get into gear (1st or reverse, depending where parked) when cold. Once I get going and it warms up a bit, shifting is ok but still kind of notchy. Seems the warmer the car gets, the better it shifts, up to a certain plateau.

So now I finally have a chance to start investigating this (along with my leaking fuel injector), but trying to figure out where to start. What immediately comes to mind is that I have air in the system and pressing the clutch pedal isn't disengaging the clutch quite enough. That makes the most sense since as the car warms, it shifts better. But would one especially hard/fast shift be able to cause this? I.e. could I have over-extended the M/C or slave cyliner and somehow allowed air in at that exact time? Or blown out a seal or something, allowing air in? This seems odd since I smash the clutch constantly in my stage rally e30, which probably has a very similar if not the same M/C and slave, and have never had any issues.

I would normally say "oh, change the fluid" but fluid would not have made it go from butter-smooth to "very notchy" within a few miles.

I know some guys have cracked/bent clutch forks, but that seems unlikely to me since this is a stock clutch and that wouldn't seem like something that would "get better" as the car warmed up.

So I guess I'm really just trying to figure out if the m/c or slave could have suddenly either "gone bad" or could have somehow allowed some air into the system at the exact moment of the hard shift.

The obvious answer is to bleed the system, which I'll do this weekend. But just advance troubleshooting to make sure I'm not totally forgetting something obvious here.

And sorry for the long post, lol...

9FF · 10-18-2018, 02:52 AM

First place I’d look is the linkage on the trans, there’s a bolt back there that can work loose. Most folk red loctite that bolt and the track guys drill and wire it.

irish44j · 10-18-2018, 06:16 AM

Quote:

Originally Posted by 9FF

First place I’d look is the linkage on the trans, there’s a bolt back there that can work loose. Most folk red loctite that bolt and the track guys drill and wire it.

I took a quick glance back there and didn't see anything that looked amiss, but will double-check. Not sure how that would affect things in terms of it changing when the car is hot or cold, though?