Bad Clutch Humming - No Motion

[TGP37]

First the low down, Getrag-282, Spec Stage3, New everything (master/slave/flywheel/clutch/etc)

Is it possible to spray clean the pressure plate and flywheel while installed? Or should I just take the massive anal reaming and pull the damn thing AGAIN......

First install it grabbed very well and would stall out in gear with brakes applied. Had it on stands at the time. Removed the block to fix a htob issue (air in the htob needed bench bled). After putting it all back together I am getting a terrible humming noise when I attempt to move the car under it's own power. Doesn't go anywhere, doesn't even rock the car any. Absolutely no motion when in gear and pedal is released but a terrible humming noise.

So I think the clutch is slipping pretty badly. The flywheel was cleaned due to a very light hue of rust. I am afraid the clutch still had contaminants when installed, or oil is leaking through the crank seal.

However, the front brakes are new and were grabbing the rotors very well during install. I always let them break free and seat with a spirited drive around the block.

Is it possible for front brakes locked to cause this? I would think the engine would stall out.

Ah man, if I got to pull that block again...................I got a headache now!

[neophile_17]

It's quite a bit easier to investigate the brakes than the clutch...

What did you clean the flywheel with?

[TGP37]

It's quite a bit easier to investigate the brakes than the clutch...

What did you clean the flywheel with?

Hot soapy water and a soft dish sponge to remove the orange rust haze, rinsed and blasted with air. Fearing there may be residue I scrubbed again with distilled water and again blasted dry with compressed air. It appeared spotless clean and wiped with lint free shop towel prior to bolting the pressure plate and disc (used alignment tool). No grease was used since I have a hydraulic throwout and that is not loosing fluid.

Unfortunately I did not blast the flywheel with brake cleaner as I now really wish I did.

Wondering if it would be possible to blast it through the service hole where the clutch line go while having a friend hold the clutch pedal down.

The thing is, it doesn't even budge the car at all. Not like trying to drive with the e-brake on, that I can feel. It is just a really nasty low pitched humming noise. The noise increased intensity with the gradual release of the clutch pedal.

I shut the engine down quickly, did not let the noise happen long but tried a few times and it simply isn't working right.

I might jack the front end up on stands and open the brake bleeder to relieve any pressure.

Ughhh, issues never ending!!!


edit: I sure hope it isn't a differential problem. I have an EP LSD in there. Installed by PontiacJeff himself so I am confident the internals are good.

edit edit lol: Hmmm, could a lack of oil reaching the differential cause the friction discs to fail grabbing? I'm not familiar with the internal workings of an EP LSD.

[neophile_17]

Well if both wheels are on the ground and it's assembled properly no type of diff should cause this symptom. I'd suspect lack of clutch engagement. Is it possible the humming noise is the pressure plate fingers rubbing something they shouldn't? I had an oil leak from the cam cover above the clutch for 12,000 miles and it never affected the clutch so I'd think a main seal leak would have to get _terrible_ to cause this issue. Given what you did to prep the flywheel I don't think contamination is your problem unless you soaked the clutch in oil.

~sam

[TGP37]

Never put any oil anywhere near the clutch/flywheel stuff. I made sure it stayed clean and dry during the slave bleeding. I too feel like it is the lack of engagement but why is puzzling me. And here is why.....

1- Trans was built by one of the best, PontiacJeff from engineered performance. And this issue wasn't present at first. The HM-282 is ready for MANY miles ahead.
2- No changes were made to the clutch/flywheel assembly when I had to extract the internal slave and bench bleed it.
3- The pedal, I can feel the engagement of the fingers. I know there is exactly 0.1" clearance w/ the slave fully decompressed.
4- There was very good engagement prior to pulling the trans to repair the slave.

One thing I remember now, may not be anything but.... I started the engine w/o the axles installed and did a quick test to make sure everything was running well. I noticed a rattling at first but it quickly subsided in seconds. Definitely not a catastrophic sound at all so it was brushed off as nothing. The clutch proved to disengage the trans well w/o the axles installed, the speedometer proved that.

There is no interference on the friction disc or pressure plate and the flywheel is bolted with ARP's nice and tight. Pressure plate is bolted with the hardest non-arp bolts feasible, I forget the class. The Bellhousing has the proper dowel pins and everything lined up great.

I wonder if a very light rusty haze can prevent grip. Maybe I could blast a few cans of brake cleaner into the bellhousing area....lol. As long as it doesn't damage the HTOB or rear main seal.
It is very possible the trans fluid is low, I planned to get some synchromesh or royal purple before hitting the road. Essentially ensuring proper levels as I don't have the dipstick to gauge. It seems irrational to believe the clutch is failing to engage 100% due to low fluid.

So low fluid won't prevent a dual clutch limited slip from engaging?

Seems logical for me to change the fluids now as my next diagnostic test...and loosen the brake pads grip. New ceramic pads on new (but machined flat) rotors.

Any advise or lead is greatly appreciated. I'm in unfamiliar territory dealing with transmissions.

[TGP37]

After thinking about it a while, it isn't impossible for something to contaminate the clutch disc or flywheel along the way. Maybe a lucky shot of brake fluid when bleeding the slave, or a fluke splash of something. Possible the lint free shop towel had an oil residue as I did do a final wipe down on the flywheel just prior to pressure plate and clutch disc install.

I was able to move the car in neutral a few inches so the brakes aren't locking anything.

Something contaminated the clutch, or the input shaft is broken/slipped? Is that possible? No abnormal stresses were encountered when the trans was bolted up.

And I decided against carpet bombing the pressure plate with brake fluid through the clutch service port. If that truly helps the problem, then nothing but a full on cleaning off the trans is desired anyways. Looks like I have a project this weekend.

[neophile_17]

It certainly sounds like you've eliminated the problems that don't require transmission removal. Hopefully it's something simple and cheap. By the time your done you will be familiar with transmissions.

~sam

[TGP37]

Funny cause part of this build was too 'learn' as I go. And well, I got what I asked for.....lol

Not blasting the clutch disc, pressure plate and flywheel with ample brake cleaner is a mistake I will not repeat again.

I think I need to figure out how to pull the trans from the bottom so I don't have to remove to much.

Thanks guys

[pocket-rocket]

See, now I don't recall the car not moving in our pm's. When I hear the term slipping when talking about clutches, I think of the car moving, but the clutch is not grabbing as hard as it should and the engine is accelerating faster than the car, like when you ride the clutch. If there was contamination as we discussed, the car should still move, just like your brakes still work when glazed over, just not as well as they should.

[TGP37]

See, now I don't recall the car not moving in our pm's. When I hear the term slipping when talking about clutches, I think of the car moving, but the clutch is not grabbing as hard as it should and the engine is accelerating faster than the car, like when you ride the clutch. If there was contamination as we discussed, the car should still move, just like your brakes still work when glazed over, just not as well as they should.

Discovered the driver axle wasn't fully engaged into the differential. No score marks, no metal debris or evidence of grinding. Not knowing exactly how that effects the LSD's function but I suppose it was the main cause, obviously...lol

Sorry, forgot to mention it failed to move, even budge.

I said it before and I'll say it again.....I can do well for myself learning and getting things done....But my f**k ups are classic.

[neophile_17]

Good to hear you figured it out and it was pretty simple. It was a good weekend for an extended test drive.

[TGP37]

Good to hear you figured it out and it was pretty simple. It was a good weekend for an extended test drive.

Ah yeah it was a very nice weekend, weather wise. I decided to clean up the turbo a bit and removed traces of coked oil, loaded it up w/ assembly lube and sprayed the turbine blades clean.

I still pulled the block out after I discovered the axle out of the differential. It was only a few more steps and I took the time to spray the clutch parts w/ ample amounts of brake cleaner. Also found a bad o-ring at the hydraulic tob and replaced it. I had a 3-day leak in the clutch lines somewhere and I believe that was it. Creating micro bubbles in the fluid and it adds up very slowly. The o-ring was deformed a little.

And I took the time to admire the WOT-TECH purchased ARP Flywheel bolts.

Lots of room around the turbo exhaust manifold, double wrapped w/ 3 coats of VHT Ceramic paint (2,500°F - 3,500°F short term). I made a conduit from 2" aluminum to route the fuel lines, a vac line and the Wideband data line and shield them from heat. Overkill, I know.

[neophile_17]

Better overkill that than flames. I need to wrap my harness to stop the melting. Better to do it while out.

[TGP37]

Better overkill that than flames. I need to wrap my harness to stop the melting. Better to do it while out.

Exactly. Plus, anything that is routed near the exhaust is secured in place so nothing hangs or works it's way down and ignites from heat. I'm considering a temperature gauge w/ the sensor recording air temps just above the pressurized side of the turbo exhaust.

I always wondered about an emergency punch switch that triggers an installed fire extinguishing system spraying every part of the engine bay, lock the fuel lines and disconnect the battery. For those who push their cars to the limit. It would be an interesting safety mod.

[neophile_17]

Fire supression systems are fairly common in racing. Not cheap but less than what you've got in the car for sure.

~sam