Some of you will remember that I've been fighting with my brand new Exedy clutch, which won't release for some bizarre reason. I've checked the cable operation, cable free-play, clutch adjustment, pedal condition and even R&Red the trans a 2nd time to verify my installation. Still, it won't release.
Well, I finally figured out my problem. It's the sort of thing you have to see to believe.
Here is my test fit of the pressure plate in the flywheel. Note that the friction disc has been left out.
It looks good, but there's a giant problem. If you look closer at the bolt hole in the pressure plate, you'll find that the pressure plate is still a good 1/4" away from the flywheel. It won't go any further because the spring petal on the pressure plate is actually contacting the flywheel. Again, there is no friction disc, so this part should slot into the flywheel without any trouble.
Here's a slightly different angle.
Here is a different spring petal that shows the same problem, but not as bad.
Notice the tiny shiny spot on the flywheel notch that indicates the petal has definitely been making contact there. It's especially pronounced because I've been beating on the pressure plate for the last 5 minutes with a dead-blow hammer.
Let's pull the flywheel and have a look at it again, on the table.
Once again, there is no friction disc here. Normally, the friction disc will push the pressure plate 1/4" out. As you tighten the pressure plate down, the gap closes while tension is applied to the pressure plate spring. It's really easy to miss this problem unless you specifically test fit the pressure plate without the friction disc.
If you put that clutch together like it is and tighten it down, it won't release. It only took me 3 R&R's, plus these to figure it out:
This was a new flywheel from Rock Auto (I think). It was sold for an 89 Accord. The clutch is an Exedy for an 89 Accord, which lots of guys here use. The old clutch fit without issues, but 3 different new clutches did not. I'm not sure how this happens, but my guess is that this is a parts interchange problem. As parts makers eliminate parts for our cars, they find the next best part that might still work to replace it. Some intern figures out that the bolt pattern and diameter of an '05 Civic flywheel, for example, is the same as ours, so we start getting '05 Civic flywheels instead of 89 Accord flywheels. I'm speculating here, but it's the best explanation I can come up with.
I took the flywheel down to a machine shop that specializes in clutches and had them clearance the notches to fit the new pressure plates. I was hoping they'd do this on a mill, but it looks like they just used a die grinder. I asked if they balanced it afterward and got some jive followed by a quick redirect, so that's a no. I'm too tired now to fight about it and there's so much vibration in the A engines, I probably won't notice a little more. The lesson here, is that if you come across this problem at home, don't bother taking it to a machine shop. Just handle it yourself with a grinder. This is what sucks about Hondas. If I'd gone in with a 33-year-old Benz flywheel, they would have oooed and aaahed about my "vintage" Benz and done the job right (maybe). When I come in with a 33-year-old Honda flywheel, it's just an old car and they do crap work. This is how small businesses sink themselves.
Here's the final fitment, which is correct.
I'm sure this is another of those obscure and difficult problems I encounter that no one else ever will, but if you do, this thread is for you.