Need a new clutch? Considerations for older cars or high mileage ones....

[Mac Attack]

I love this thread. Thank you for sharing all this.

I wish I had your help for this next phase - Putting it all back together!

I'm glad I used a real mainshaft to check the clutch plates/pilot bearing alignment before placing it back in the transmission housing. Those plastic alignment tools are junk, and my pressure plate housing had to be loosened, the mainshaft inserted, and then the pressure plate housing torqued down again. Now the mainshaft can slide in and out Should help out a little later today....

Now I'm just waiting for an extra pair of hands to stick everything back in the transmission case. I'll do a dry run trying to fit the case on.

View attachment 148631

 

[goldNSX]

All I can say now is TAKE YOUR TIME and doublecheck everything. Better safe than sorry afterwards. Good luck!

EDIT: forgot to mention: make sure the collar of the 5th gear shift piece is in the right direction. If it's not you won't be able to put the ball/spring in it. The SM talks about that. -> SM

 

[Mac Attack]

It's all together!

You'll need a helper to place the mainshaft, countershaft, shift forks, and reverse idler. After that, I simply tilted the case such that the shift forks stayed against the sleeves. As Thomas says, make sure everything else is aligned and do a dry run. I had no problem setting the top half of the case without a second set of hands.

The snap ring wouldn't fit completely in the countershaft bearing initially. It was on top of the bearing, but wouldn't seat even though the cases were completely together. therefore, I just ran four bolts into each corner of the housing and flipped the transmission over so the weight of the countershaft would seat the snap ring. I didn't have to tilt it much before I heard the reassuring dull click. The snap ring is snug and able to rotate slightly in the housing recess... Success!

If you do need to tilt the housing to seat the ring, make sure there is no residual oil that could run out and mess up your Hondabond. My parts were assembled lightly coated with MTF - some really apply it liberally. You don't want a leak after all this.

Watch the detent balls per the SM. There are four. One is larger than the other three, and one of the other three has a shorter spring on it. Ran through all the gears and it seems to work fine :smile:

Thank you GoldNSX for the tips and tricks! Much appreciated!

Next up is positioning the transmission under the car, then somehow getting it onto the transmission jack saddle. Wish I had a lift!



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[goldNSX]

Congrats! You have the 'project of the year' now.

The 4 springs and 3/1 balls are of different dimension according to the SM.

When I completed mine I ran it through the gears 'like I was sitting in the car'. At that time someone had a problem with the 4th gear not going in straight.


Greasing the clutch is the next step. Not too much grease esp. on the splines on the mainshaft.

Mounting it back is not that difficult. You'll need to apply the more force the more far you go in. Getting the mainshaft in the flywheel bearing is combination of force AND wiggle. I was laying on the floor and pushed with my legs...

 

[Mac Attack]

Mounting it back is not that difficult. You'll need to apply the more force the more far you go in. Getting the mainshaft in the flywheel bearing is combination of force AND wiggle. I was laying on the floor and pushed with my legs...

Not that difficult? I can't even get the mainshaft to align with the first clutch disc splines. Unbelievable... I'm at the point where I'm considering dropping the engine.

 

[goldNSX]

Take your time...AND DO NOT DROP THE ENGINE.

You might have to turn the crankshaft (clockwise!) or the mainshaft (gearbox) a little bit to get a good match of the splines.

Good luck!

 

[Mac Attack]

The engine is pretty well supported with the passenger side mount and my jack under the oil pan (with a large block of wood of course). Every night I support the engine on a stand as my jack tends to have a small leak and will drop 0.5cm over night.

Got it in the first clutch disc somehow. I'm giving up for tonight. I'll try rotating the crankshaft clockwise a little bit tomorrow.

This is embarrassing. I've never had problems getting it in before. Must be old age. :wink:

 

[goldNSX]

Got it in the first clutch disc somehow. I'm giving up for tonight. I'll try rotating the crankshaft clockwise a little bit tomorrow.

There should be no need to rotate now. If the discs are aligned 100% it's more a question of the correct angle/height. In my case the engine was tilting down maybe 1-2 degrees. The more far I went in the more I had to lift the gearbox. When the resistance got higher I knew that the gearbox has to be lifted by a few mm. But even then I had to push it on with my legs.

 

[Mac Attack]

I agree, but at this point I'm getting desperate to seat this thing. I don't like the thought of placing undue stress on a clutch disc or the transmission mainshaft... and that probability increases the longer I leave it like this.

I've refrained from using my legs to push it over at this point (because of placing to much side force on the jackstands), but I think I will go ahead and try to push with my legs while holding on the suspension upper A-arm. Mine is tilted down about the same 1-2 degrees. That angle is still needed due to clearance issues and makes it a pain to re-attach.

 

[goldNSX]

I had the same concerns back then. But believe me it's a combination of repositioning the gearbox and pressing. There no need to turn the crankshaft now if it's already in the first clutch disk if the alignment of the of clutch is 100%. If it's not then you have to realign it again but I don't think this is your actual problem. I know of one clutch job where they were simple too lazy to unscrew the lower control arm with the result that the first clutch disk got misaligned while taking the gearbox off. It needs quite a lot of force to misalign it...

While you push it to the 'end' of the first clutch disk you might feel that it gets the more and more resistance. This has two reasons: 1. more area, more resistance. 2. the main reason: when the engine tilts down and you push horizonally the gearbox has to be positioned the higher the more you go in.

Brute force won't function if the gearbox is not in the correct position. There's no need to use as much force as if you try to push the car off the jackstands. Medium force (20-30 kg?) AND wiggle + repositioning the gearbox will do the job. You have three barriers: 1. 1st clutch disc, 2. 2nd clutch disc and 3. the flywheel bearing. The last step is the hardest part. I've tried it several times with different gearbox levels, tried to push it back in with ONE leg and finally, it just slided in. Me and my friend were doing this as a one man job. Of course you could get someone who helps you to push while you try to wiggle it in.

I'm pretty sure you work it out. Good luck!

 

[Larry Bastanza]

This could be mis-alignment with the splines. For checking the dif preload there is a special tool that goes into the dif(like the intermetiate shaft does). If you put the trans in gear, slightly rotate the dif, maybe having the put the intermediate shaft in if you do not have the tool. Should allow it to go in. I typically put the trans in place get it close, then rotate the dif, and it slips right in.

BTW, did you use a proper pilot shaft to align the splines on both clutch disks?

HTH,
LarryB

 

[Mac Attack]

Thanks Thomas and Larry for the tips and tricks.

Before re-assembling the transmission, I used the actual mainshaft to align the clutch discs. In the past I've used the cheap plastic tool and it was "difficult," even with the transmission and engine out of the car. I thought this was a clever idea and would make it a lot easier trying to put the transmission back in.

I think the main problem is that I've done this by myself so far, and I'm a little dude without much upper body strength. I have a buddy coming over Saturday to help.

In the meantime, I've been trying to get the transmission aligned with the engine as best as I can visually, then wiggling while trying to shove it in (even with my legs). The mainshaft is through the first clutch disc, but just won't seem to go into the second. I've been very careful to keep the transmission and engine aligned while the input shaft is through the first clutch disc, because I don't want to hurt the disc or the mainshaft.

We'll see Saturday. If it won't go into the second disc, I'll probably have to pull the transmission back off and try to realign the discs... this time with the plastic tool.

 

[Larry Bastanza]

Sounds like it is not exactly level. Are you using a floor jack? Also make sure you have the clutch fork in place. Even though I have done this over 100 times, last one I did, I slid the trans in place, and said, oh crap, you left the fork out!!!!

 

[Mac Attack]

I only have the passenger side engine mount supporting the engine, and have a floor jack with wood block under the oil pan to shift the engine up/down as needed.

I have a HF hydraulic transmission jack supporting the transmission.

Got the fork in place - I actually placed a note on the transmission reminding me of that!

 

[goldNSX]

If it won't go into the second disc, I'll probably have to pull the transmission back off and try to realign the discs... this time with the plastic tool.

Honestly, I think at that stage and time already spent I'd pull the gearbox back off right now and check with the plastic tool. My friend spent hours of trying to mount it after having misaligned the clutch disc during his 'lazy' gearbox work (lower suspension arm not removed). I used the OEM Honda tool and I can tell you it get stiff when it's fully in. You need to pull by aprox. 5-10 kg to pull it out again. Not sure about the plastic tool. Try with the plastic tool first and get a feel of the resistance.

I had Asylum's deluxe gearbox lift back then...As it held 100% of the weight you could concentrate 100% on dialing in the position.



Oh, yes, good hint, don't forget clutch fork!

I'm pretty sure we'll hear a releaving hurray on Saturday evening.

 

[Mac Attack]

It's in :smile: Thanks everyone for the tips and encouragement.

Now I need to get the rest back together....

 

[goldNSX]

What was the problem?

 

[jwmelvin]

Yay!! [emoji3]

 

[Mac Attack]

The problem is that I couldn't get it aligned perfectly with the transmission jack, and then didn't have enough strength to wiggle it in if I lowered the jack out of the way a bit.

A friend goes a long way with this job. First, holding up the rear hubs while you slide the axles out, then removing the transmission, and finally, re-assembly. My wife helped holding the hubs, but the transmission alignment was a little tricky.

While this took about a week fiddling around with the reinstallation, it mostly sat until I could have a buddy come over and help. I really only spent about 30 minutes total trying to wiggle it in myself.

Now all I have to do is torque the axle nuts to 240 ft-lbs and stake them, then start it up. I'll check the clutch pedal play later.

For those of you that have the '02+ headers, be very careful tilting the engine down to gain clearance: I damaged the rear O2 sensor because it hit the vertical "A" brace while lowering the engine. I bent the metal sheathing around the wires. The wires look OK, so for now, I'll see if it throws any codes or has the stumbling issue. Here I was worried about stressing the three main coolant hoses as I lowered the engine, and didn't notice the O2 sensor was rubbing.

The newer Exedy twin organic HMG12SD clutch is about 25% stiffer pedal feel than the OEM clutch and the RPS twin carbon I just removed. Some extra pedal effort was expected with a stiffer pressure plate to hold the torque, and it seems liveable. The clutch pedal moves sooo smoothly now. It wasn't bad before, but this is really nice. Even though I ran it through the gears while the transmission was on the ground, it was a nice feeling that it seems to work OK installed in the car.

Hopefully the roads will be dry this evening to take it for a test spin. Thanks again everyone for the help and encouragement. I still prefer tearing into an engine than a transmission though.

 

[Mac Attack]

Ugh, I have a check engine light. It's probably the rear O2 sensor as expected. I'll pull the code later. Otherwise, the engine ran fine in safe mode and I took it for a quick test drive. Edit - Yes, it's code 42 for the rear O2 sensor heater. I've got a spare!

This clutch is just like OEM, except about 25% stiffer. I love it. No chatter, no shudder, no floating midplate noise, and easy to modulate. And, it has the quality you'd expect from an OEM supplier. It may not have the lowest moment of inertia compared to other offerings, but that just makes it more driveable on the street.

If you're making up to 525 WHP, this is the clutch to get. Can't wait to get 500 miles break-in on this.

 

[goldNSX]

Take your time with breaking it in esp. with that amount of power. I've found that it takes very little to get a fishy clutch smell when new.

 

[Mac Attack]

Take your time with breaking it in esp. with that amount of power. I've found that it takes very little to get a fishy clutch smell when new.

It's only 3.3 degrees C outside and I'm still on summer tires, so yes, I'm driving very carefully!

Ran great on the way to work. Even at 3.3 deg C (38 F) and a cold car (non-heated garage), my current GM synchromesh blend made cold gear selection smooth.

Next up is reinstalling the diffusor and lowering it a tad....
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[JLCoolman]

Congrats on getting it all back together Dave!

Thanks for the review on the new Exedy twin organic HMG12SD clutch.
After doing some more reading on Prime, I'll be debating between that one and the Exedy Twin Plate Racing Clutch HM012SD in the future.

Just in case anyone else is interested, here are some relative threads regarding the Exedy clutches.
http://www.nsxprime.com/forum/showthread.php/199982-Exedy-twin-organic-clutch-who-s-running-it
http://www.nsxprime.com/forum/showthread.php/180833-Exedy-Stage-4-twin-disc-clutch
http://www.nsxprime.com/forum/showthread.php/146724-Exedy-Hyper-Twin-Clutch-Kit-Acura-NSX-Pull-type
http://www.nsxprime.com/forum/showt...sk-Organic-Clutch-for-the-1991-1996-Acura-NSX

 

[goldNSX]

I've mentioned the 'break in procedure' because if done too aggressively you're likely to end up with a shuddering clutch again. It really needs time and 1.2 k miles esp. at that power level. Until the friction material transferred from the clutch discs to the pressure plates and the clutch surfaces get broken in things get really hot. A little bit of burnt fish smell is ok as the friction discs have to vent a little bit but too hot is very bad.

BTW did you measure you old clutch for wrapping? Unevenly distributed friction material can also induce shudder.

 

[Mac Attack]

Break-in is being done very carefully! I'm not making much power off idle, and certainly am not making the clutch very hot.

Rob Smith (of RPS clutches - maker of this SOS clutch) previously volunteered to check out my old carbon clutch, so I'm going to mail it back for inspection. When he was helping me with my shudder issues on the phone, he told me to do a few standing starts in 2nd gear, and then let it cool. Very, nice, friendly person. Maybe it was my ISB causing my issues? I'd like to think so. Regardless, I have a SOS twin carbon clutch with 6k miles I'd like to sell and recoup some of my costs... after it's inspected by RPS.