Hydraulic Throwout Bearing Issues (maybe) - help!

[James OLC]

Originally Posted by JamesJ

The trans has ATF fluid in it? If you put 30W it will have problems shifting. I have to disagree about upshifting and downshifting, upshifting is easer to do with out the RPM "matched" Drive around and shift with out the clutch and see ow it acts. Maybe you will learn somthigng else that can lead you to the answer.

James - that is my opinion with respect to shifting as well. I can upshift much better (in general - not specifically with the '67) with only partial clutch or no clutch at all. My rev matching skills on downshifting can definately use improvement (and assistance via the clutch). Since the whole package (engine, transmission and clutch) were fresh I was trying to "take it easy" on everything at the time - relatively speaking.

Transmission fluid is Rockland spec Tranzilla fluid.

[James OLC]

So... couple of things already this morning. First is that I am at a loss as to how to properly gauge the throw of the TOB in it's "dissassembled" state - at least by myself. I'll get some help this afternoon because it would seem that (with the stock GM TOB) you need one person to "compress" the TOB to it's in situ depth while the other person presses the clutch pedal. Without the TOB compressed, pumping the clutch pedal has no effect other than to (eventually - with multiple pumps) pressurize the complete slave to it's full extended (dissassembled at rest) depth.

Second, I pulled the clutch out (leaving the bellhousing in place for simplicity at this point. I didn't see or find anything that stood out to me but I took some pictures of the individual components for your input:

The Flywheel and base ring:


The Pilot Bearing:

[James OLC]

Flywheel Disk (back or Flywheel side):


Flywheel Disk (front or pressure plate side):


Pressure Place (back or flywheel side):



Pressure Plate (front or clutch side):

[James OLC]

Clutch Disk (back or pressure plate side):


Clutch Disk (front or clutch side):


Clutch Back (disk side):


Clutch Front (transmission side):

[James OLC]

If anyone sees anything or wants more detail on anything let me know. Like I said, nothing obvious to my (inexperienced) eye.

There is probably 100 miles total on the clutch - some polite street miles, some sort-of inpolite track miles...

And for the record - checked the transmission fuild level - it was completely full and clean with no indication of contamination.

[KEISLER]

Originally Posted by reboot04

Does anyone have any suggestions, ideas, or recommendations on what these measurement mean and what remedy there may be?

My first thought was maybe bad TOB?

Any help would be appreciated.

Thanks,
James

** DELETED BY KEISLER DUE TO IRRELEVANT CONTENT **

[James OLC]

Yeah... thanks

And now back to something that's actually relevant/applicable...
(sorry pet peeve)

I'm still waiting for the replacment TOB (should be here tomorrow) but, following Andrew's advice, I picked up a proper Quartermaster machined alignment tool. More annoying than self serving tripe is the useless alignment tool that McLeod ships with thir clutch... you would think that when you charge nearly a thousand bucks for a clutch, you would include an alignent tool that fits the application (then again, I would also think that when you sell a scattershield for an LSx you would include metric hardware - but what do I know).

So the clutch is back in and as soon as the TOB show's up I'll change the hydraulic lines and reinstall everything.

[XcYZ]

Shafi, I don't see what pushing your kit has to do with the downshifting issue that James is seeing.

James, out of curiousity, did you check the bellhousing centerline alignment?

[James OLC]

I didn't see the relevance there myself...

The McLeod bellhousing makes it really difficult to check or double check any of the conventional alignment or runout specs - the big irregular hole might make it easier for some things but a consistent reference it is not. There is no indication on the pilot bearing or the input shaft of it being out of alignment but it is something that I am trying to rule out.

[KEISLER]

Originally Posted by reboot04

Yeah... thanks

And now back to something that's actually relevant/applicable...
(sorry pet peeve)

I'm still waiting for the replacment TOB (should be here tomorrow) but, following Andrew's advice, I picked up a proper Quartermaster machined alignment tool. More annoying than self serving tripe is the useless alignment tool that McLeod ships with thir clutch...

James, that is a lame reply to someone trying to help you. On the Pro-Touring.com website, I responded to your same call for help on the same issue here. Since my post above was unclear, I'll post some more information that should be a little more relevant:

First, here is the response I posted on P-T:
"James, I have not read all of these post replies, but I can tell you that if your numbers are correct then you are constantly engaging the clutch fingers and it would be a wonder the clutch is not burned up.

If the 2.25inch number is correct, you need to reshim the bearing to 2.10 - 2.0inch compressed and not any more. You can see my comments about why on the other thread mentioned with the Pontiac guy with the Weir bellhousing.

If you hit a wall on this, PM me and we'll help you further."

It's clear to me - with the experience of selling more than several hundred of the same McLeod bearing you are using, and more than a couple hundred McLeod Street Twin just like you are prematurely toasting - that either the wrong bearing piston size was sent (bolt-on design) or you installed it wrong (slip on design). Either way the instructions that came with the product *should* have provided you with adequate information to prevent this problem.

Next, you can set up the bearing however you'd like, but I will tell you what you *should* do if you don't want to continue ruining the clutch:
1. maintain .150 +.05 / -.03 clearance from the fingers of your clutch to the face of the bearing in the compressed state
2.A) if you are using the McLeod slip on type, LOCKTITE BLUE the thread in sleeve so it doesnt' back in or out, because it will likely change position if you don't
2.B) if you are using the McLeod bolt on type, the pistons are numbered 1-8, and they increment in .200 inch. So you will will need to determine which piston change by the amount of interference or air gap. You can't do this with the unit apart as you are trying to do.
3. pre-bleed the entire system, then install it to the car and final bleed it
4. if you did everything above correctly, AND you have the correct master cylinder bore and stroke AND you have connected it to the pedal at the correct location to achieve the correct throw WITHOUT bottoming out the master cylinder before landing the pedal on the floor THEN the clutch should release at 1/3 to 1/2 of pedal travel. IF it releases at the top of the pedal, then you need to go back to square one and recheck you numbers.


A couple other tips for the McLeod hydr bearing - both slip on and bolt on:
1. if it comes with banjo joints, throw them away and make hard lines. You can get the inverted flare seat fitting with the correct male side to screw in from most any good hydraulic store
2. get a couple spare sets of o-ring kits from them 'cause you will need it and you don't want to be stuck without one. They used to send a spare oring set with the unit just for this purpose.
3. run DOT4 fluid


Good luck