I received a response from Bill, looks like he did not notice my prior email about the shudder issue etc.. and only responded to the whirring video I sent as a reply to my first email. I have sent a follow up to him on those original issues/questions again.

He stated on the whirring:

"
At idle and transitioning from idle whirring is indicative of a worn pilot located in the rear face of the engine crankshaft providing less than ideal centering support of the far end of the transmission input shaft in turn the spline mesh alignment contact point between input shaft and clutch disc experience a harmonic resonance that is transferred to the transmission case where it broadcasts the whirring noise during flow normalization. This audible byproduct is your indicator for keeping track of pilot degradation over time. Uneven radial wear of the clutch disc friction surfaces (outer region wears faster than inner region) increases as pilot centering ability decreases.
"

Followed by:
"You can hear the whirring sound but not at an obnoxious level. Replace pilot and disc if it gets twice as noisy or entire clutch if the clutch starts slipping under load."

So he seems to feel that the sound is the pilot bearing, and it's not bad enough (if that is the ONLY thing wrong) to do anything about it yet. But again I do not think he saw my comments about the shudder I want to address.

 

A year ago I replaced my clutch PP TOB slave and MC on my 96. Looking back on it I should have gone with the RAM. The cost would have been the same. The product is a newer design and appears to be superior. Plus there is no sending new parts off to be checked by someone else etc... That never makes you feel good when the $450 clutch you just bought isn't properly made.

I sent my PP to ZFdoc and it was way way off. He sent me a different one that had the proper post height and was ready to go. He also checked my clutch disc and said it was balanced. I used a Fidanza aluminum flywheel. My DM was moving alot and had tons of burn marks on it from the previous owner. I took my DM flywheel and the new flywheel to a local machine shop and they balance matched the Fidanza to the DM. The DM is counterbalanced so you need to have your new flywheel matched or it will vibrate.

I did mine on jack stands just like you're talking about. I never took my transmission out from under the car. I used 2 ratchet straps to keep it strapped in place on the trans jack. It is very heavy and if it falls or rolls over it can hurt you. Leave the transmission in 3rd gear when sliding it out of the bell housing. It will go back far enough to clear the bell housing and shifter hole when lowering it. I left it on the jack and pushed it as far down the tunnel as I could. I also replaced the shim and the dust cover that ZFdoc came up with. NOTE: Please very careful when installing the dust cover. It is coated in rubber and needs to be driven in place evenly. Otherwise you will cut the rubber and it will leak....ask me how know...ugh.

I also went with the short throw shifter. That's a very nice upgrade and worth every penny in my book. I did that in the car. The worst part about that job is driving the pin out and back in that attaches the shifter to the trans. I used and air chisel with a punch on it. That would have been easier to do from outside of the car. But I was doing mine at a later date and time from my clutch install.

When re-installing never pull the transmission to the bell housing with the bolts. If you do that you can damage the bell housing and the pilot bearing. When properly aligned you can push the transmission all the way up to the bell housing. Don't forget the aluminum shim that goes between the transmission and bell housing. It can be frustrating get it lined up while under there but it will go in. The top driver's side bell housing to the block bolt is the worst. Without that one this all comes apart pretty quickly.

Be sure to get a manual and use all the proper torque specs.

If you do have to replace your flywheel and the new one comes with a coating over the mating surface be sure to clean that off prior to install with paint thinner or some other solvent. I was told it would melt off after the first 10 shifts on the first drive. Well my first drive only had 2 shifts due to another problem that cut it short. Well that stuff wasnt all the way gone and it glued the disc to the pressure plate. I couldn't get the car to disengage the next day after sitting. Luckily it was parked where I normally worked on it. I had to take the disc out and clean it off. Yeah that didn't make me very happy. But the second time through I did it all in about half the time. I was also told that stuff can smell really bad, dead animal, at first run and wear off but goes away quickly. A year later if I slip the clutch at all I can still get a slight smell. ugh...

Yes, I made some mistakes along the way and I have told my stories here before but I would rather other members read my mistakes and not make the same ones I did.

This is hard heavy work in cramped spaces, but like you I love it I do find it satisfying once it is all complete. Now, what else could I do so I have to take my car apart again...headers, exhaust...hmmm.....hahahaha.

 

Thank you for more great info!

I got another email from Bill re: shudder...I guess I'll see when I (finally) pull it apart...:

"
Shudder occurs during clutch modulation while transitioning from stationary to moving in either direction and always caused by a combination of disc anomaly that has one spot a little thicker and pressure plate not parallel when fastened to the flywheel. Many production vehicles received high delta manipulated Valeo clutches.

Centerforce was carrying higher quality TO bearings if replacement needed. I can’t guarantee that they still are.

I have never installed a RAM clutch. There is a human error factor when setting up the clearance between bearing and pressure plate spring fingers. As the clutch wears, the fingers get closer to the release bearing. Get the gap wrong and the clutch will short life.
"

 

I would still rather have my RAM, I am sure it will live longer than the stock setup I installed (with the machined PP, SMF and stock type clutch). That setup lasted about 800 miles and in all those miles it was slipping!
I was told by Bill after I removed it and sent it all back for him to inspect that I should not have used any Loctite on the pressure plate bolts and that contributed to my clutch slippage. But he did admit that the disk was probably not the correct setup for my car.
I will never know the real reason for the slipping but I can tell you that I did use Loctite on the PP bolts on my RAM setup and there is no slipping at all. It could be because it is the 900 series disk and flywheel but I am sure it would not slip with the 300 series either.
It is just a better setup overall.
I didn't even drill into my bellhousing like RAM suggested. If you have an inspection camera you can align the hydraulic throw out bearing on the dowel pin with a bit little bit of effort.
These are the pictures of the slipping setup I replaced with the RAM. Talk about uneven wear! To me it looks like uneven clamping pressure from the pressure plate. But I am no expert.

 

How do you like the RAM setup so far (install, pedal effort, etc)?

I’ve not seen a lot of feedback on the forum.

 

It works well, I am very happy with it. The clutch engagement is a bit higher in the pedal than stock.
The pedal effort is no more than a stock type setup.
Actual clutch engagement happens quicker than stock (which is nice), probably because it is a hydraulic throw out bearing versus the slave and a separate throw out bearing and the fact that the disk is a sintered iron disk.
The 900 series I have can sometimes feel too aggressive. At times like when driving like a granny the clutch will chatter from a dead stop. It likes a bit more RPM than a stock type clutch disk. It likes a quick release not a slip type engagement.
It grabs real hard and launches well.
All gears seem to shift much smoother than before regardless of speed.
The single mass setup is a bit louder than stock when you lug it or accelerate hard in an upper gear. Any single mass flywheel conversion setup tends to be noisier than the stock dual mass flywheel.
I do have the shim from Bill installed in my transmission and the noise isn't that bad at all. Idle is just a tad noisier than stock but certainly not objectionable.
As far as price is concerned the RAM is about the same as a stock single mass conversion setup.
I spent more for the stock type replacement with a single mass flywheel setup. And of course I spent more than I should have because that stock type replacement slipped terribly and I had to change it to the RAM.
The RAM conversion kit is very complete. It has the throw out bearing, different size shims, clutch disk, pressure plate, balanced flywheel, stainless braided hydraulic hoses and all the fittings. The only thing it didn't come with was a clutch alignment tool, flywheel bolts (ARP bolts are recommended) and brake fluid. I bought the RAM steel alignment tool to ensure my transmission was going to engage the splines properly. When working on my back I didn't want a hassle with transmission alignment.

 

^awesome feedback, appreciate that! The RAM kit has always intrigued me, especially when taking into account issues with pressure plate leg standoff height, slave cylinder replacement availability, etc. It can be dealt with but your case is a prime example of all that prep still resulting in a bad clutch system.

when it comes time I’m sure I’ll have some more questions for you. Hopefully I’ve got another season or two on my stock setup. Thanks again for the response.

 

I agree, when I needed a replacement clutch there were really no reviews on the RAM. But after my problem I said what the hell the RAM can't be any worse than what I pulled out.
Also Mike Norcia at RAM was good at answering all my questions. He would email me back promptly as I had a bunch of questions for him.
I actually put about a thousand miles on the RAM, now my Vette is away for the winter months.
Here is a picture of my RAM hydraulic throw out bearing setup mocked up on my transmission and bellhousing before installation.

 

I would think that could be adjusted with the TOB shims, if you wanted it lower.

 

Nice, thanks for the pictures. I took a quick read of the RAM instructions and it doesn’t look TOO bad. How difficult was the install in your opinion.

 

Installation was not much harder than the stock type setup. It involves a few more steps.
You need to do some measuring with a straight edge to get the hydraulic throw out bearing setup correctly. I needed all the supplied shims to get mine within the gap specified in the instructions.
Also they wanted you to drill into the magnesium bell housing so that you could get a long screwdriver to help align the throw out bearing onto the new dowel.
I decided not to drill the housing and get the hydraulic throw out bearing into position with the use of my fingers. I then used an inspection borescope through the opening where the old clutch fork use to go to make sure it was located properly while inserting the transmission into the bellhousing.
The fork opening is where the braided stainless hydraulic hoses come through now. The braided lines are just stiff enough to help with the positioning of the bearing if needed.
Bleeding the hydraulic throw out bearing is much easier than the old hydraulic slave was.
Here is a link to several of RAM installation instructions. There are specific ones for the C4s.
https://ramclutches.com/hydraulic-be...-instructions/

 

Update: finally got the trans pulled. Most annoying part was getting my corsa off in one piece (it fought me at the passenger cat). I got 20” of lift measuring to the pinch welds. That is plenty. I am nice and sore after all of that!

Will post more after I get the bell housing off. Someone definitely has been in there before, and see if you can spot their first mistake (hint I know why my pilot bearing whirrs).



Just fits!!!


Setup to pull trans.

Slid out the back no problem (had to tilt)

Hmmmmm

Hmmmmm, hard to see but that is the grooved bronze bushing

 

Glad to see you got the beast out. I have to say I never saw a pilot bearing that looked that bad. When you install the new pilot bearing make sure you install it dry in the crankshaft bore. Do not put any lube on the input shaft either, when reinstalling the transmission.
Maybe the last guy who did the job lubricated the bearing and caused it to prematurely fail. Bill Boudreau told me to never use any grease or lubricant on the pilot bearing or it will fail.

 

Ding ding ding. Hard to tell from the photos but the pilot bearing/shaft are caked in grease...and it's a bronze oil-impregnated bushing, NOT roller.

 

Yeah, that would definitely cause problems. Is the end of the input shaft still okay? That would really suck if it's jacked up.

 

Seems to be fine...have some corrosion to clean off of the case so that the surfaces mate true (could also contribute to pilot/align issues and all could be contributing to shudder by causing uneven clutch wear [please see zfdoc comments above #21,cannot wait to get the bellhousing off])


Before

Quick wipe with paper towel (can feel no roughness with fingernail)

Have some corrosion to clean

More

 

Alright...I got all of the bellhousing bolts removed (PITA, I definitely need a swivel socket set for better clearance).

Now for actual bellhousing removal: What did you all do about the cat exhaust brackets? Did you remove the cats or ? FSM says "remove entire exhaust"...but I was hoping only cat back was necessary. Also did you need to remove the starter?

 

I can't help you RE the exhaust, because mine had long-tube headers and cats way far back from stock. I didn't need to loosen or remove the headers, but I doubt that helps much. I did remove the starter. I can't swear that it was absolutely required, but it's easy to do (at least with the headers) so I yanked it.

 

I have headers on mine too so I didn't need to remove the cats.
But when I installed the headers I did end up cutting the bracket that attached to the catalytic converter. If memory serves me right the passenger side cat bracket was attached to the bellhousing. So I am not sure if you can pull the bellhousing with the cat and bracket still in place.
Sorry I couldn't be more helpful.

 

So what you are telling me is I should let this snowball to LTs? ...I've wanted to do ARH with high flow cats at some point but yeesh not cheap and then I'm into the exhaust manifold/bolts and then wires/plugs and then might as well freshen the opti and then water pump and then what about seals and then... I am planning to do O2 sensors while I'm here anyway though!

The cats themselves are not in the way...however the stock cat support brackets on both sides bolt to the bellhousing. I think the passenger side I can just unbolt the bracket from the cat (if the bolts aren't seized)...the driver side may be difficult trying to unscrew the studs that are holding the bracket, so I may need to drop one or both cats... Since someone has been in here I will try and see what bolts have been cranked on and hope those are easier to break free since they've been off before. It's just odd to me in all my searching/instructions/FSM/zfdoc etc... there is little to no detail between the point of getting the transmission removed up to the point of dealing with the clutch fork/TO bearing in regards to the bellhousing removal...the FSM says "remove entire exhaust, see section 6F" going to that section appears to refer only to the catback...

Also, in regards to above braces, this nugget from the FSM:
"To eliminate undesirable noises from transmitting into the vehicle TWC braces were installed between the transmission and TWC on (VIN P) models. These braces are nonserviceable"