Got the car back! Okay so it looks like they (may have -- we can't tell for sure) smashed the wiring harness right before the harness end of the O2 connector. It actually didn't look that bad but there was some damage to the sheathing there. My mechanic basically replaced about a foot worth of the 6 strands of wiring there. We also had to replace the O2 sensor. Not happy about it, but he made a good repair to it and everything is running properly now. I think I'll go ahead and buy a spare engine harness just in case, but I'll leave the old one in there for now.

Now for the good news, the vibration is gone. Now I have a chance to be able to tune my car since we know the Centerforce was indeed the cause of the vibration, maybe just maybe the vibration was the cause of the knock... Will make a new datalog after I break in this new clutch properly.

The clutch, while less grippy than the Centerforce, is more grippy than the OEM and seems to be working well. Shifting still feels a little off. I'll give it some time to let things settle in and then I might try putting the Bluefish bracket back in there (after I give it a paint refresh).

In regards to the suspension, it feels great. I think I'm done with suspension stuff for now, I'm pretty happy with it suspension-wise and look forward to putting it to the test.

2 steps forward and 1 step back. I guess that's the way it goes sometimes. Right now I'm just glad to have my car back!

BackInBlack said:

2 steps forward and 1 step back

Click to expand...

It may seem slow, but it sounds like progress to me...........carry on!!....

I'd read that Centerforce clutches have similar vibration issues when the weights get stuck and don't return as expected, failing to evenly slide along the pressure plate diaphragm springs. In those cases, they snipped the wire and removed the weights with no ill effect.

I read about that too! (In a corvette forum!) That was actually the first thing we tried after we balanced the flywheel and found it to be true already. The weights didn't seem to be stuck either, but it's hard to say if they were moving the way they're supposed to or not. After the weights were removed the vibration increased significantly. It seems they balance these things with the weights on. With the weights there was a minor vibration (but regular and noticeable) at around 4000 RPM or so. With the weights off there was an increased vibration throughout the RPM range. It seems the pressure plate itself was a little off, but can a clutch like that truly be balanced with those weights on it? I think this clutch is not good for high revving cars. Probably better for classic type cars that don't rev as high...

The weights can actually be removed without cutting the wire. It's surprising there aren't more stories of weights flying off with how the weights are attached. There are about 6 square ... let's call them washers, that seat down around the diaphragm spring fingers and block the weights from travelling too far outwards. The weights themselves have a groove that holds them onto the pressure plate fingers and lets them slide back and forth with a thin wire that runs through all of them, the only thing holding them together is a 90 degree bend at the end of the wire. Behind the weights is a thicker stainless steel ring that sits in a groove in the rear of the weights and keeps them all in alignment with each other. The only thing that keeps them from sliding off of the fingers is the wire, and centrifugal force! I will say, I had no disastrous issues though and I really liked the clutch. I just don't think the vibration mine had is good for my worn engine.

Whoohoo! Ford has a wiring harness repair kit!
There's also an aftermarket version:
Time to drink down the Milwaukee's Best and make some lemonade!

BackInBlack said:

The only thing that keeps them from sliding off of the fingers is the wire, and centrifugal force!

Click to expand...

I'm guessing you're looking at it uninstalled. When in the car, the transmission input shaft is filling some of that space. It might be that there's not enough space between the end of the finger and the shaft for the weight to get through.

I wonder if they balance these at a high-enough rpm for the weights to be in their outer positions. I think a slight imbalance at low rpm would not have as much effect as an imbalance at high rpm, so optimizing the high-rpm imbalance would make sense. It could be that 4k rpm is when the weights move position, and the shudder you had there was an issue with one or more of the weights taking a little more rpm to move. There would be a natural imbalance caused by some weights being in the "outer" and some at "inner" positions in an rpm window. That said, 4k feels high for the "activation" rpm.

Yeah. Honestly I doubt it's the cause. I'm just hoping it's something other than the engine ya know.

When I talked to Centerforce about it they told me they have plenty of high revving race cars running these. I'm sure it's true but... with the minor issues my engine already has I just don't want to risk contributing to it's decline... It could be that the vibration plus my scored cylinder walls combined to make a bigger problem. We'll find out after 500 miles!

Here's a video I found of one spinning up

Lots has been going on... progress, but not functionally. So this past year, I've been trying to locate the cause of some knock/misfire that's been going on with my car. This led me down a rabbit hole doing all sorts of things, and ultimately led to two possibilities: A. The engine itself, B. A vibration in the driveline. Wanting to chase down the last possibility, I started looking at the most probable cause of the vibration: flywheel and/or clutch. Transmission was dropped and flywheel was found to be well balanced. Removed Centerforce clutch weights and vibration got worse. Replaced clutch with Exedy Mach 500 and I initially thought we got the vibration but it's still there, intensity reduced somewhat. Currently occurs at idle-2000 RPM and comes back at around 4000 RPM. Vibration is accompanied by a metallic scratching/grinding noise. Noise is most noticeable at idle and doubles in intensity if the A/C is on. Noise doesn't occur if transmission is cold, and doesn't occur when the clutch is disengaged (pedal pushed in). Driveline vibration is most noticeable at high RPM and high speed (4500+ RPM/80+MPH) and is felt in the center of the car although the shifter is not vibrating. Vibration is worse in some gears over others: In 6th I can feel no noticeable vibration. Vibration appears to be worst in 5th gear, is moderate in 2nd and 4th, and is barely perceptible in 1st and 3rd. The Centerforce clutch I was running previously had weights that caused metallic chatter at low rpms. This would have masked any other noise that was going on, and since my transmission is newly rebuilt, I didn't suspect it. But now with the new clutch and having broken it in, I'm pretty certain I've got an issue with a transmission bearing, probably the transmission input bearing. When I went to rebuild my transmission last year, I suspected at that time that my primary issue was the transmission input bearing. My rebuilder replaced a lot of things, but when it came to the bearings, they said they looked at them and that they were good so they left the original bearings in. This is my memory anyway. If there was noise after the rebuild, I wouldn't have noticed it due to the Centerforce chatter. And there were various other minor transmission issues before the rebuild. Good news is, I talked to my transmission builder and they've agreed to take it down again no charge. I'm pretty certain at what they'll find. Currently scheduling this and trying to go easy on the car.

More bad news: My mechanic jammed the adjustment mechanisms in my Koni adjustable struts. I tried what I did before, working them back and forth with an adjustable wrench and the passenger side broke free once again. The driver's side broke. So I've been running with my struts at full hard since I got my car back. Good news: Koni is giving me a 50% off replacement that will get installed next week.

More bad news, I just noticed that the driver's side panhard bar bolt hole is rounded out and is probably causing some clunk. It's not terrible and it'll hold for now. But I'm planning a trip to the junkyard to dismember some Ford 8.8 axle housings...

I got my wiring harness repair kit and it looks good. Planning on installing that sometime in the future, but for now the repair is holding.

Sorry not much good news to post, but I do have my car back, it's running and the end of this mess appears to be in sight. If I'm right about the transmission, the 2nd rebuild should bring big results...

Wishing you good luck on the vibration fix. It's been quite a journey you've been on and it's nice to see you still seem to have an upbeat attitude.

So, I've read that in order to keep from locking up the adjuster on these Koni struts, that you need to torque down the top center nut by hand, AND you're supposed hold the adjuster from moving while doing that. I called Koni and asked how to do this, they recommended an O2 sensor socket, which I have, but is the wrong size and the hole in the side isn't big enough. So I talked to mechanics, and they all said, how the f are you supposed to do that?

I'm guessing you guys already know, but in case anyone else is like me and didn't know, apparently there's something called a, "strut nut socket" that no mechanics or shops seem to have. I found this one from Steeda and hopefully my jammed up Koni woes are over.

" Necessity is the Mother of invention " strikes again!!!

BackInBlack said:

So, I've read that in order to keep from locking up the adjuster on these Koni struts, that you need to torque down the top center nut by hand, AND you're supposed hold the adjuster from moving while doing that. I called Koni and asked how to do this, they recommended an O2 sensor socket, which I have, but is the wrong size and the hole in the side isn't big enough. So I talked to mechanics, and they all said, how the f are you supposed to do that?

I'm guessing you guys already know, but in case anyone else is like me and didn't know, apparently there's something called a, "strut nut socket" that no mechanics or shops seem to have. I found this one from Steeda and hopefully my jammed up Koni woes are over.

Steeda Strut Nut Socket - 19mm

Steeda likes to make installs as easy as we can on our customers, and the right tools make jobs so much easier. And the Steeda Strut Nut Sockets do just that!

www.steeda.com

Click to expand...

I have the full set of those in my tool box. I have also used the craftsman max access socket set on some strut nuts. The hollow drive allows another tool to pass through the tools and hold the shaft.

Replacement strut installed. Feeling quite relieved. It's working great and I got one of the best alignments I've gotten yet in this car. Running -1.2 degrees camber and that's about all I can do with the current setup. Suspension is feeling good. Pretty much where I want it. Might make some small tweaks later on.

I have an appointment locked in with my transmission builder. They agree it sounds like bearings. However, they warned that since MT-82 uses roller bearings, they think it's pretty unlikely this would be the source of any vibration. So, I'll do some datalogs and make sure that my O2 sensor wires are working properly after the previous debacle and after that, I'll relax and enjoy the ride. I will say that my oil consumption seems to be down. Maybe there's a chance this engine will redeem itself after all?

BackInBlack said:

I got one of the best alignments I've gotten yet in this car. Running -1.2 degrees camber and that's about all I can do with the current setup.

Click to expand...

On the front?

Junkyard Dog said:

On the front?

Click to expand...

Yeah, S197. Just street config right now. Reason I say it was a good alignment is b/c they got my caster, toe, thrust angle, etc. dialed in about as well as it can be. Sometimes after an alignment I find that they've messed up some stuff.

Koni warrantied my broken adjuster strut

Transmission is back at builder, has been disassembled and has unfortunately been given a clean bill of health. By process of elimination that leaves the engine as my only remaining possibility for the cause of my issues. Too bad.

Gonna have them replace bearings just in case and that's that.

Will try one more WOT pull when it's done to see how things are doing but I'm probably stuck with things as they are until I can justify a new short block a couple years down the road. At least I don't have to think about it anymore for a while!

Well, I got the car back. No big surprises, everything working properly. Noise is about 50% reduced. I guess those bearings helped a little. Gonna make some adjustments to things and will make a new datalog soon to see where I'm at. I think I'll also move to 19x10 wheels in the future to reduce some of the wheel gap I've got. I'll stick with 275x40 tires, they seem good for my use. Today I checked my fluids and bolts, got a shiney new piece of plastic interior trim installed and then I'll wash the car. Then I'll be lazy the rest of the weekend! Have a good weekend all.

Took the Whiteline transmission bushing out yesterday. It's been on the car for some 10 years or so but it still looks to be in good shape. So far, no noticeable change in shifting. The only change so far is the car is quieter on the road -- significantly quieter. I can still hear the gear noise, but just barely. I'll drive it this way for a while and see how it does. If shifting problems do crop up, I'll do the modern MGW shifter first. Got a couple other small issues to work on. Found transmission fluid spattered around underneath the car. Mostly on the bottom of the transmission where where it's bolted/gasketed together, a bit on the drain plug, and some on the driver's side of the trans tunnel. I don't see a leak, so I'm hoping it was just a sloppy drain. Cleaned it up and will keep an eye on it. Ordered a new drain plug so I will replace that and do a fluid swap soon just in case. QTP cutouts are also having issues... Will remove them for now and see if I can repair them off of the car.