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Guess the thread title can't be edited? Spelling fix for title: Clutch Intermittently slipping Part II.
So I bit the bullet and crawled under the beast to perform the mighty clutch inspection replacement etc.
Got everything out and the disk / flywheel / PP all look great. The only noticeable thing is a semi deep grove on the throw-out bearing guide and one of the inside sides of the fork shows rubbing marks. I'm guessing that the throw-out bearing is getting stuck on the guide and that a full clutch release is not happening all the time. Other than that I'm 100% sure I need to figure this out before reassembly as I don't want to do this job again anywhere in the near future.
FW = Stock
PP = Stock
Disk = 930
Anyone ever had this happen to them??
Thanks
Mike G.
Last edited by Golden Hands; 01-02-2024 at 12:44 PM.
Reason: Spelling error
Here's a better pic of the clutch guide. Does this amount of wear usually occur on these guides? I'm wondering if the throw-out bearing was getting stuck and not allowing the clutch to engage.
I'm somewhat perplexed as to what 930 disk is the correct one as there are the same part number disk at many different vendors and the price is significantly lower at some!!!! The place listed below in the link is less than 1/2 price of the other vendors.
If the clutch disc is in good shape, I recommend that you resurface the flywheel and the pressure plate if they were not new when you installed the clutch disc. The flywheel and the pressure plate do not wear evenly on a radial plane. You can check this with a straight edge and a feeler gauge.
Whiles goofy around looking at the difference between the 930 and the Club disk it came to me that torque capability of disks is deceiving.
From the formula for transmitting torque the club disk wins. The club disk has smaller surface area, but that don't matter!". WTH right? The club clutch has a larger I.D. which ends up giving the average contact radius are larger value which gives a higher torque capacity. Anyway if you mess around with the I.D. of the disk in the formula at the bottom of the page you will see that increasing the I.D. gives higher torque capacity. I know I know as you approach a infinitesimally small contact area the capacity goes very high which can't be true, but.... My buddy and I at work still think there has got to be something with surface area that increase capacity, but there is no evidence to that. haha. I am ignoring all other things relevant to the actual design of a clutch disk of course.
Maybe this has been argued to death already in the past but it's still interesting.
I would not surface the pressure plate, instead I would replace it because it is so much time and effort to do this job. If you are committed to resurfacing and keeping the pressure plate, I would recommend inspecting very closely the springs on the plate. One or more could be weak or broken and causing an asymmetrical force on clutch engagement/release. This could explain the wear on the guide.
Already purchased a new PP and Disk. Just don't want to take the chance. But for fun I am going to test the load on the old one and then kick my self in the butt because there is nothing wrong with it or the disk. lol
BTW I do know for a fact that the throw-out bearing guide was off centered from the last SOB that installed it. They must have not centered the guide with the tabs that stick out of the guide that should register into the bellhousing centering hole feature. When I removed the guide I noticed that 2 of the guide tabs had been crushed. I suspect they placed the guide up in the bellhousing and just started tightening the 3 bolts with a powered ratchet wench before centering the guide. So they never noticed that it wasn't centered after the bots with tightened down. I even tried to center the guide in the bellhousing but it was impossible as the 2 bent tabs interfered with the bellhosuing and didn't allow that. Kinda really sucks that a $7 part installed incorrectly cost me $$$$$ and 30-40 hours of time rolling on the ground by the time its all done.
You haven't mentioned how much power/tq you're running? Or plan to run. Now's the time to upgrade if you anticipate increasing performance in the future.
Pretty much stock but some extra boost 14-15 psi boost with an A-Tune kit.
Here's the kicker. I've been driving my self crazy after I called the balance shop local to me. First he mentions that he needs the crankshaft to balance the flywheel and PP correctly. He says he needs to put the proper bob weights on to get it right. I start researching only to find out that for an inline 4 cyl it is 100% not necessary to have the bob weights on the crank for balancing the crank. So now I'm starting to think he may not know what he's talking about.
Why you ask. In line 4 finally does something right.
Then he actually states that the new PP comes from any vendor well within balance spec. I'm thinking maybe he doesn't want to do the job, haha. He also mentions that the vendor (SACHS) probably has the correct fixture with a crankshaft/bob weights to get the or PP balanced. But that really makes no sense to me either as I'm really starting to believe that both the PP & FW are neutral balanced. So yes I could take the FW & PP to a machine shop but the 2 shops that I called said there is no advantage and thought it wasn't worth while.
Mike G.
Last edited by Golden Hands; 01-18-2024 at 12:10 PM.
Now I've been told by 10 shops that it is much better to have an unbalanced flywheel. They even recommended arbitrarily drilling holes wherever I pleased and even adding weights using JB weld.
Ok how far did you read this until you realized this post is just for humor?
01-01-2024, 09:50 PM
Clutch interment slipping part II
