Need help from the clutch gurus about Mcleod setup

[drdano]

I need some help from the clutch gurus...lots of questions as usual.  This is the clutch that was behind my worn out 390 in my car.  This clutch is from Mcleod, organic disc, diaphram clutch, matching throwout all connected to my TKO600.  Everything has a max of maybe 1500 miles total on it.  No burnouts, no tomfoolery, the tired 390 couldn't even chirp the tires with 4.11 posi in the back.  Just a few around town trips and then the yearly pilgrimage to Bonneville with the car.

I'm finishing up assembly on my 428 right now and giving everything a good looking over while I've got it out.  I've got some concerns on the clutch parts though.  First the flywheel had scratches in it like the tracks between songs on a vinyl record.  Very thin and barely catchable if you ran a fingernail across.  I could still see the machining marks from when the flywheel was resurfaced. 

So, were these scratches likely just caused from dust and debris?  Everything was super clean when I installed it.  There is nothing shiny on the flywheel side of the clutch disc that looks like it was dragging, and all the rivets in the disc face are still a good ways down in their respective holes.

Next, there are rivet heads in the clutch disc that are cracked.  Looks like a manufacturing defect to me because the cracks are only where whatever cutter is used to trim the head down left a chunk on there.

Lastly the throwout slung all it's grease out.  I'm reasonably positive it wasn't over greased on install or idling against the clutch fingers while the car was in gear.  Is there a reasonable explanation of what would cause it to puke all the grease out and get a ton of slop like in the video?

Has anyone seen this with Mcleod parts before or is this just a series of flukes all at once?

Rivets:




Pressure plate side of clutch disc


Flywheel side of clutch disc


Pressure plate face.


Grease from throwout




Throwout



Video of play in the throwout bearing

http://www.flickr.com/photos/44602356@N06/6444503733/

[rcodecj]

Not a clutch guru but:
That clutch was slipping, due to who knows, maybe incorrect linkage adjustment, too high of gears, whatever, but it was slipping.
As far as the clutch rivets go, I think you got a defective clutch.
Lastly, I have had throw out bearings that looked like they "slung all it's grease out", but it never got on the clutch or pressure plate surface.

[machoneman]

Former clutch guru (hah!) but I still like Long/Borg-Beck clutches better. The clutch wasn't slipping IMHO and the circular marks and color or the metal look normal for such a low mileage clutch set-up. Here's literally the first pic I grabbed off the 'Net (down a ways) of a burned, scorched and 'blue' heat-checked flywheel.  Also, check the inside of your bell' again. A slipping clutch will throw off lots of black clutch dust,  dust that isn't present in your pics on the disc, flywheel nor clutch cover.

http://www.mazdas247.com/forum/showthread.php?123774160-HELP!-Mazda3-clutch-failure-at-42k-and-dealer-warranty-issues

The rivet heads on the disc do look poorly finish-machined (more like finish-butchered!) and should look better. Still, if the anti-chatter springs aren't rattling around (s/b tight and no play) I'd reuse it. In fact, the whole set-up looks so good no flywheel face nor clutch face machining is needed. For peace of mind, slapping in a new disc would  work but I wonder if the new one would exhibit the same poor workmanship. Maybe try another brand of disc and check it closely before installing same.

The throw-out bearing is trash. Some do seem to throw a lot of grease off but that much in 1,500 miles and the play between the two shells?  Get a name brand bearing that doesn't come in a white (overseas)  box.

[drdano]

With regards to black dust, no, there is not any on the pressure plate and barely any on the disc.  The flywheel did have a small dusting on it, but nothing worse than on any normal clutch job I've ever done.  They flywheel has since been remachined and rebalanced.  For $35 it's good piece of mind and I wanted the balance checked since the new 428 is neutral balanced.

If I can get ahold of Mcleod today I'll send both the disc and the bearing in for them to look at.  When I set up the clutch I recall setting the air gap through the starter hole (what a freaking nightmare!) and there was a good 1/4" of space between the clutch fingers and the bearing so I called it good.  I couldn't actually measure with anything, this was just with calibrated eyeball looking through the clutch fork hole in the bellhousing.

The throwout sounded awful the past few months.  The last few trips out anytime I had the clutch pushed in it sounded like it had sand in it, obviously nearly dry in retrospect.  What brand would be better for the throwout?  I have no idea who actually builds stuff stateside anymore.  Hays, Lakewood, Luk, other ?

[machoneman]

Next time check the air gap with the tranny out. Don't know on the quality bearing since it's been a while since I needed to buy one. Perhaps Summit / Jeg's can recommend a USA built brand or one another poster chimes in and makes a recommendation.

[RICK LAKE]

Hi Dano I see a bunch of issues with your setup, could we start at the beginning.
Was the bellhousing setup to center on the block and crankshaft? if not this will cause binding problems and damage
A clutch is a clutch, different styles are just that. I see a glazed flywheel and blown thrownout bearing We don't have pictures of the other
side of the pressure plate. Like to see what the forks look like. Same for the throwout bearing, looks chewed up where the fork is. Any chance of
of getting pictures of this and the fork end? Does the fork pivot smooth in the bellhousing or is it sliding forward? Is there a return spring to pull the
fork back to a stop? Some more pictures would be nice. Will try and walk you through this,
Lets start with pilot bushing or bearing, is it new and does it fit into the back of the crank and it is not loose ot wobbling, Be careful with hitting it into the crank shaft. Bass punch and soft hammer. A hard socket and damage the case of the bearing, chip the bronze bushing. I add a little grease to install either
Next bellhousing being centered. IMO this is a must. Takes time. You can get offset pins to center on the block. It took me 3 hrs to get a lakewood, .038" back on center. Alot of grinding, extra long pins and welding nuts to the bellhousing so is permanent centered on this  block unless a major failure happens.
Ok lets install the clutch. EVERYthing clean of oil, grease, even finger prints. I use gloves for this part. Get you centering dowl and install it in to the pilot bushing or bearing. This dowl should be new. It should fit snug in the hole. IF its loose or falls out, we have a problem and need to measure the inside of the bushing or bearing and the end tip of the input on the trans. Fix this problem.
Next install disc, again dowl should hold disc in place and centered. Pressure plate has some weight, install couple
of bolts on the bottom to help control the weight. Torque bolts to 10 pounds and keep crossing them until you reach the correct spec. Want to pull down the pressure plate evenly.  I use blue loc-tite to stop them from coming loose over time. Install the clutch fork and throw out bearing in the bell housing
If you can hook up the linkage for the throwout bearing.some system you can them check the air gap with the clutch engaged. you want between .035" and .055" on the air gap to get full release of the pressure plate on the disc. If not enough air gap, adjust fork rod, same applies for too much clearance. This will do damage to the pressure plate fingers. Once this is done, install the trans. The last thing is to check the travel of the clutch pedal and not overextend the pressure plate with too much pedal travel. Have found that a small braket or a block of wood works the easiest to limit travel. . One last measure ment, measure from the flat face of the trans to the tip of the trans input shaft. Them with the bellhousing on the motor measure to the bottom of the center of the crank. Need to make sure you are not pushing the crankshaft into the thrust bearing in the motor and do MAJOR damage to the motor. In some cases with a lakewood bell housing you need to cut .380" to prevent damage of the thrust bearing. I have seen this happen with a ford motor and GM input shaft trans. Good luck. This should walk you through the process. If you think you still have a problem , call me, I might be able to walk you throught this.732-254-3536 in the evening after 7pm EST time. Rick L.

[drdano]

Rick, thanks for the reply.  Here are some answers to the questions:

Bellhousing is from Quicktime and centered in at .0015" out of the box.  The TKO's are pissy with centering, so this was all inspected during mockup and again before final install.

I can't see the other side of the pressure plate unless I dissemble the pressure plate assembly.  It looks painted red from what I can see through the release fingers.

Camera is charging, I'll get some photos of the backside of the throwout.  The only markings I see are where the two clutch fingers are under the clutch finger holding tabs.  Doesn't look trashed.  The same contact points on the clutch fork fingers look fairly normal, just a bit of shiney-ness.  The scarring on the face of the throwout is discoloration, not gouging, I cannot catch a fingernail on it.

Clutch fork return spring was used and it was functioning correctly.  There was a visible 1/4-3/8" gap between the throwout face and release fingers when I set it all up.  The fork return spring does not use a stop to limit the return, I think the back of the throwout just rests against the input shaft hub of the trans.

Pilot bearing is a bronze oolite unit, BH50 I think.  Contact pattern of the input shaft is 5/16" into the bushing and nothing looks abnormal, no wobbling or weirdness.  I would have liked to have a deeper depth of the input shaft, but it was either this or the input was hitting the back side of the crank with the first bellhousing I mocked everything up with.  Car was never ran with that bellhousing, it was corrected first. 

The flywheel was cleaned with brake cleaner prior to install along with the pressure plate face.  I did nothing with the clutch disc but remove it from the box and install it.  The alignment tool to hold everything in place was new and fit so snug I ripped the ring off the end of it trying to pull it out and had to use a big pair of pliers to pull it out. 

ARP pressure plate bolts were used with blue loc tite, everything installed and torqued to spec in star pattern.

The trans worked great, shifted fine and everything seemed all and well.  The past few times I drove the car the only issues I had was the throwout sounded dry when I pushed the clutch in.  The other is there is a plastic tab on the clutch pedal that insulates it to the clutch assist spring under the dash.  That insulator snapped and the clutch engagement was a bit choppy since the assist spring was now riding metal-on-metal against the clutch pedal.  I may just remove the assist spring altogether since I barely had any tension on it and it wasn't doing much of any good.

[drdano]

I thought I'd post a follow-up to this issue.  Things have been a bit crazy the past week with my daughter arriving last Wednesday by surgically-trained stork.  This morning there was a box from Mcleod sitting in front of the door to the shop.  Inside was the disc, pressure plate and throwout I sent them for inspection and a note explaining everything.  The return slip said they had repaired the clutch disc with new rivets, however it looked like a new unit in a new box.  However the rivets look good on this one.  The pressure plate they said they also rebuilt, but again, new unit, new box and looks good.  The throwout had a "continuous sealed bearing" installed on it.  It looks and feels much tighter than the one before.  Does anyone have any experience with these?  I assume this type is supposed to live longer where it may be idling on the pressure plate fingers?  Oh, and the best part--all replaced under warranty including the return shipping.  I'll definitely give these parts another shot in the car, this is excellent customer service that sadly is pretty rare these days.

[jayb]

Great to hear about that excellent customer service!  Good luck on the install - Jay

[machoneman]

I thought I'd post a follow-up to this issue.  Things have been a bit crazy the past week with my daughter arriving last Wednesday by surgically-trained stork.  This morning there was a box from Mcleod sitting in front of the door to the shop.  Inside was the disc, pressure plate and throwout I sent them for inspection and a note explaining everything.  The return slip said they had repaired the clutch disc with new rivets, however it looked like a new unit in a new box.  However the rivets look good on this one.  The pressure plate they said they also rebuilt, but again, new unit, new box and looks good.  The throwout had a "continuous sealed bearing" installed on it.  It looks and feels much tighter than the one before.  Does anyone have any experience with these?  I assume this type is supposed to live longer where it may be idling on the pressure plate fingers?  Oh, and the best part--all replaced under warranty including the return shipping.  I'll definitely give these parts another shot in the car, this is excellent customer service that sadly is pretty rare these days.


Nice, good follow-up by you and McLeod's positive response. Actually, a continuously sealed throwout bearing is more the norm these days (no grease nipple) to avoid the modern super aggressive clutch dust from getting inside and eating up the bearing surfaces.