High RPM clutch drag

[bk7794]

On my 00 Civic I notice that if I take it up past 4 or 5k that 2nd gear is incredibly difficult to get into. I figured typical used car fashion that the transmission was just beat on heavily with a lot of city miles. I then came across this today http://www.8thcivic.com/forums/mechanic ... -read.html and it got me thinking.

I still haven't tried double clutching to see if that helps. I will work on that sometime.

[ClutchFork]

I wonder if these cars have rev hang? That would make it hard to shift into the next gear. But if the rev's drop sufficiently it should shift just fine, unless there is a high rpm clutch drag that lingers after rpms drop. I don't know, just thinking out loud. Maybe don't really know what I am talking about.

[ClutchDisc]

I doubt that a 2000 would have rev-hang.....as I don't think drive by wire was used in cars until later.

[tankinbeans]

Clutch delay valve perhaps? Or would 5k be too early for one of those to kick in?

[Shadow]

I wonder if these cars have rev hang? That would make it hard to shift into the next gear. But if the rev's drop sufficiently it should shift just fine, unless there is a high rpm clutch drag that lingers after rpms drop. I don't know, just thinking out loud. Maybe don't really know what I am talking about.

Rev hang doesn't make it hard to shift into another gear, it just makes it harder to shift smoothly into the next gear if you're not familiar with driving a car that has rev hang.

[Shadow]

Clutch delay valve perhaps? Or would 5k be too early for one of those to kick in?

Clutch delay valve isn't RPM-dependent. In simple terms, it just prevents the driver from using the clutch like a switch. In other words, it limits the speed at which the clutch can be engaged.

[theholycow]

Rev hang would make double clutching more difficult, but has no effect on single clutch shifting (other than the elephant kicking your rear bumper if you dump the clutch in the next gear while your rev hang is still happening, of course). A 2000 model with cable throttle can have rev hang but is less likely than a DBW car.

Clutch delay valve would not make it difficult to get into the next gear. CDV doesn't delay clutch disengagement; that happens every bit as fast as your left foot hits the floor. It only delays engagement, so no matter how fast you dump the clutch pedal it doesn't engage too fast.

I don't think RPM can affect clutch drag in the way that that post seems to imply, where clutch drag exists only at high RPM. However, if there is clutch drag then it will be much more easily noticed at high RPM even if it's impossible to detect at lower RPM.

[daleadbull]

Could it be the engine mounts?

Maybe the rocking of the engine at high rpms is making it harder to shift into the next gear?

[bk7794]

I kind of am doubting this entire theory myself, but it's definitely worth a good thought. Reverse gear is also all buggered up so I Am guessing its the damn previous owner. Definitely thinking of possibly opening this transmission up and changing a few things.

[potownrob]

no rev-hang, all mechanical (FTW?!? ), just gotta either double clutch or take longer to shift. had same issue with my 94 civica.

[Rope-Pusher]

I've seen vehicles where the clutch drags at high engine rpm. I don't remember if they were modular clutch or not, but the clutch disk wasn't even spinning, just the engine, flywheel and clutch cover assy. When I get back to work, I'll axe my buddy what they found when they tore them apart.

[bk7794]

no rev-hang, all mechanical (FTW?!? ), just gotta either double clutch or take longer to shift. had same issue with my 94 civica.

My 91 doesn't have this issue and it's got 3 times the mileage.

I've seen vehicles where the clutch drags at high engine rpm. I don't remember if they were modular clutch or not, but the clutch disk wasn't even spinning, just the engine, flywheel and clutch cover assy. When I get back to work, I'll axe my buddy what they found when they tore them apart.

Alright please let us know! I was wondering because the clutch engages so low because that was what the guy claimed fixed it.

[Rope-Pusher]

no rev-hang, all mechanical (FTW?!? ), just gotta either double clutch or take longer to shift. had same issue with my 94 civica.

My 91 doesn't have this issue and it's got 3 times the mileage.

I've seen vehicles where the clutch drags at high engine rpm. I don't remember if they were modular clutch or not, but the clutch disk wasn't even spinning, just the engine, flywheel and clutch cover assy. When I get back to work, I'll axe my buddy what they found when they tore them apart.

Alright please let us know! I was wondering because the clutch engages so low because that was what the guy claimed fixed it.

A low engagement point is synonymous with not having much reserve pedal travel - it's barely getting disengaged. With not much clearance when disengaged, all it might take is some mis-match between the centerline of the crank and the centerline of the trans input shaft and there could be a wobble that is exacerbated at high rpm. Have you tried bleeding the hydraulics to get the engagement / release points higher off the floor?

Another thing that might cause this is if the clutch cover wasn't bolted to the flywheel evenly. Best is to have a multiple-runner tool tighten all the bolts at once. second best is to do a star pattern, like you tighten-down wheels. Wurst is when you just go around the perimeter and tighten them as you come to them. That can impart a tilt to the clutch cover relative to the flywheel.

[ClutchFork]

FYI and if it is of any help and I don't remember if you had the master cylinder replaced, but the last two clutches I had replaced ended up with the pedal engaging at the floor. In both cases the master cylinder was bad. One had a reduced stroke from crud buildup and the other had a very slow leak (think it was an internal leak if that is possible). On mine, it would work fine until the weather got cold and then the engagement was below the floor, or in other words I had to shut it off to engage first gear and once it warmed up it would work again.

[bk7794]

I probably should state that the engagement isn't like it's right off the floor. It's about in the middle of the travel. All other gears shift fine at high rpms. I still haven't double clutched it into 2nd.

A low engagement point is synonymous with not having much reserve pedal travel - it's barely getting disengaged. With not much clearance when disengaged, all it might take is some mis-match between the centerline of the crank and the centerline of the trans input shaft and there could be a wobble that is exacerbated at high rpm. Have you tried bleeding the hydraulics to get the engagement / release points higher off the floor?

Another thing that might cause this is if the clutch cover wasn't bolted to the flywheel evenly. Best is to have a multiple-runner tool tighten all the bolts at once. second best is to do a star pattern, like you tighten-down wheels. Wurst is when you just go around the perimeter and tighten them as you come to them. That can impart a tilt to the clutch cover relative to the flywheel.

That's interesting, I knew it was important to do tighten it down evenly, didn't know it could cause this type of a problem. Though like I said earlier, the engagement point feels like it's middle, it's not like it's right off the floor. Maybe I can make a video describing the issue.

FYI and if it is of any help and I don't remember if you had the master cylinder replaced, but the last two clutches I had replaced ended up with the pedal engaging at the floor. In both cases the master cylinder was bad. One had a reduced stroke from crud buildup and the other had a very slow leak (think it was an internal leak if that is possible). On mine, it would work fine until the weather got cold and then the engagement was below the floor, or in other words I had to shut it off to engage first gear and once it warmed up it would work again.

Ah man, yeah the engagement point on mine seems to stay constant.

The reason why I actually brought up my 91 because it's got a cable clutch and the engagement point was always absurdly high because of our great adjustments we never performed on it.