Clutch release bearing installation

Okay this is embarrassing. I appreciate any advice.

I finally got my rebuilt SOS Sport 350 clutch and put it all in. Only to find out that my clutch does not disengage. I felt a little vibration through the pedal when pressed while the engine was running and heard a bit of sound when releasing it while the engine was not running. I was bummed (having put everything back together).

Looking back I believe I know the problem but would like to confirm if possible before redoing the entire thing. I didn't snap the release (throwout) bearing into the fingers of the pressure plate. It was just loose in the assembly between the disc and pressure plate. Here's a picture before I put the transmission on.



Appreciate any guidance for a first timer who just screwed up.

-Jason

One additional thought: it seems to me that the fork should have pulled the release bearing into place when activated by the slave cylinder. But that didn't happen, I'm guessing because the fork pushed the release bearing too far off center when I inserted it. Do you think there's any realistic chance I could manipulate the bearing through the fork access hole so that the fork can pull it into place in the release plate? Or do I definitely have to pull the transmission off?

EDIT - Oops, looks like this guy had the same problem with the SOS 350 install:

http://www.nsxcb.co.uk/showthread.php?10538-Ed-s-DIY-clutch-replacement

You'd think the instructions would have at least a note for this. Again, sorry.

Since you'll be pretty good at this, can I bring you my car for a clutch swap? I just got my Harbor Freight 800lb transmission jack, but a lift makes it sooo much better.

jwmelvin said:

One additional thought: it seems to me that the fork should have pulled the release bearing into place when activated by the slave cylinder. But that didn't happen, I'm guessing because the fork pushed the release bearing too far off center when I inserted it. Do you think there's any realistic chance I could manipulate the bearing through the fork access hole so that the fork can pull it into place in the release plate? Or do I definitely have to pull the transmission off?

Click to expand...

If you were able to snug the transmission up to the engine block then the release bearing is at least centered where it should be. The inlet taper on the bearing matches another generous taper around the transmission input shaft, so the bearing has to be centered and snug at this point.

My new Exedy clutch has you pre-load the pressure plate before the clutch is installed to insert the release bearing within the pressure plate fingers, but it's hard to tell from your picture how the bearing is supposed to go. I can't tell from the picture/angle if it's supposed to sit out on a different release bearing lip. Did the instructions say? Your pressure plate fingers look like they have the correct angle, but again, it's hard for me to see in the picture and not having experience with this particular clutch.

While a sudden hydraulic failure is possible but unlikely, the only things I can think of are:

* Your release fork is not installed correctly
* Too thick of clutch plate used during the rebuild
* Wrong pressure plate used during the rebuild

Sorry. Hopefully the transmission doesn't have to come back off. I'm about to do my clutch swap and am not looking forward to the reassembly part of the process.

View attachment 147387

Thanks Dave I appreciate your thoughts. I understand what you are saying about the taper on the transmission side. I don't understand why the bearing wasn't pulled into place when first activated. Hopefully you are right that the fork isn't in correctly, as that will be the easiest fix.

I plan to start by pulling the front beam, shift cables, and slave cylinder to get access and try to see what I can figure out. At that point if I cannot get things right then I will pull it all apart again. At least this time it will be easier since I have strategies for each of the hard-to-reach bits; and I still have all the labeled baggies for fasteners.

Edit: I suspect that there is nothing wrong with SOS's rebuild as the clutch made some odd mechanical noises when I depressed the pedal. To me that suggests something wrong with my install.

Mac Attack said:

EDIT - Oops, looks like this guy had the same problem with the SOS 350 install:

http://www.nsxcb.co.uk/showthread.php?10538-Ed-s-DIY-clutch-replacement

You'd think the instructions would have at least a note for this. Again, sorry.

Since you'll be pretty good at this, can I bring you my car for a clutch swap? I just got my Harbor Freight 800lb transmission jack, but a lift makes it sooo much better.

Click to expand...

Dave, I really can't thank you enough for finding that for me. At least I understand what I did wrong. I agree that it's too bad the SOS instructions don't mention the step of seating the release bearing. Shame on me for not reading the service manual.

While it will take some time to redo it all, it will help make this a lesson I don't forget! And like you say, the lift makes it a good bit easier. I only have the HF scissor jack for the transmission, which doesn't go as high as I would like but is definitely a big help.

Mac Attack said:

Since you'll be pretty good at this, can I bring you my car for a clutch swap? I just got my Harbor Freight 800lb transmission jack, but a lift makes it sooo much better.

Click to expand...

It would be an honor and a pleasure to help you with that or another project. And I am serious.

I would think you ran into the same issue as my mechanic who installed my Exedy Twin Organic clutch. Take a look at page 7 on this manual and see if it helps some. I didn't do the install but from the description it seems to be the same problem.

http://www.nsxprime.com/forum/attachment.php?attachmentid=124376&d=1433246082

Thanks [MENTION=31854]furinax[/MENTION] that does seem to be a similar issue. My problem was more that I didn't even try to get the release bearing in the springs. Hopefully it isn't that hard to do once I pull things apart. But seeing the Exedy method is useful knowledge. I appreciate the help.

Looks like you already found the answer but I'm afraid, you must take the gbox off again….

From your photo, I can see the edge of the spring lever/diaphragm which means, none of them are inserted at the groove of the release bearing (blue arrow).

Looks like all of them are just sitting at the end of the bearing where the release fork is going to be inserted during the gbox installation (green arrow).
The release fork actually pulls the top hat section of the release bearing.

I just hope you didn't damage the pressure plate when you operated the release fork after the 1st installation....


Kaz

Thank you Kaz for confirming. After ~4.5 hours, I now have the release bearing properly seated and the transmission back on. Still have all the rest of the assembly to do but I'm feeling hopeful.

What a great community we have on Prime with excellent members and such informative advice. Can't beat that!

Sent from my A0001 using Tapatalk

Looking good, Jason.

Please remember to pack the internal groove of the release bearing with the Urea grease (yellow arrow).
And very thin coat of the same grease at the mating surface - the outer surface (must be free from rust, debris) of the release bearing guide mounted on the CL case.
Probably you were already aware of the above but I normally prefer doing it well before installing the CL on the engine so just wanted to remind you.


Kaz

Kaz-kzukNA1 said:

Please remember to pack the internal groove of the release bearing with the Urea grease (yellow arrow).

Click to expand...

Nope, I messed that up too. I coated, but did not pack, that area. I suppose I have to pull the transmission off a third time...

While ideal to pack that small volume with urea grease, I wouldn't necessarily remove the transmission again to thoroughly pack it. As long as everything was well-cleaned and coated beforehand, I think it would be OK to leave it.

If you don't want to remove the transmission again, I'm willing to bet the release bearing will slide smoothly on the transmission collar for the remainder of that clutches life.

My $0.02.


If you decide to pull the transmission again, maybe consider replacing the input shaft bearing. I'm shopping for the parts now myself, and it looks like it's 91002-PR8-008, plus an oil seal and spring washer (91216-PR8-005 and 23927-PR8-000). These are for my 5-speed, so the 6-speed that you have is probably different. My transmission has 126k on it, so it's probably a bit worn, and may have contributed to the shudder on my old SOS twin carbon clutch. Maybe not, but there's no doubt it sees some abuse and is cheap insurance to replace.

Same thing with the main seal on the crankshaft. Mine was leaking when I removed the clutch at 121k miles.

We really need a good thread or wiki on tips/tricks for clutch installs.

[MENTION=12356]Mac Attack[/MENTION] thanks. I am struggling a bit with the decision. The input shaft bearing and seal will be done when I switch to the dual-spline shaft I have so I can use a dual-disc clutch. For now I am tempted to leave the bearing unpacked but I'd hate to need attention any sooner than necessary.

I understand your dilemma. But if you're already making plans to replace it sooner than later, I'd just leave it alone. It's not like you didn't grease it at all, and personally, I'd rather put a little less grease on the transmission shaft splines and release bearing surfaces than too much.

Hopefully this new Exedy twin organic clutch released two years ago will be a nice balance. I should have mine installed by the end of this month and you're welcome to drive it. The dual-spline shaft opens up a bunch of options.

I was just in Baltimore two weeks ago and occasionally travel to DC for work. If this clutch proves friendly in stop-n-go traffic, I may begin taking it on nice days. Otherwise, let me know if you're ever in the Pittsburgh area!

I couldn't bear the idea of putting so much effort into this project and knowing I did something wrong so I pulled the tranny off and greased the bearing properly. It was a lot easier the third time. Should be back on the road soon.

Yay it's done! Just went for a test drive and everything felt great. Thanks again for the help Dave and Kaz.

3 years later and I have clutch that wouldn't lock up. So it wouldn't grab in any gear. I took it apart and see nothing wrong--the throwout was still in and looks like your picture, but should it be fairly tight as mine has plenty of clearance on all sides and even though it can't come through, it's very loose.