clutch install gone horribly wrong

[sonicnofadz]

One day, I blow my clutch disc up. I have extreme trouble shifting into and gear (grinds like crazy)...so I take the tranny off, and I discover the clutch in pieces. So I replace the clutch disc, I check the flywheel step height (.610) and I buy a branch new SBR street disc and slap it in. Now I have everything back together, but it is still extremely hard to put into any gear (at first the car had ALOT of trouble even starting) and it grinds badly. The pressure plate itself is stock. I replaced the throw out bearing and everything else that needed replacing. Why won't my car go into gear!? Maybe I should use an extended slave cylinder rod? Any suggestions would be extremely helpful. Thanks.

 

[Amazin' Wasian]

One day, I blow my clutch disc up. I have extreme trouble shifting into and gear (grinds like crazy)...so I take the tranny off, and I discover the clutch in pieces. So I replace the clutch disc, I check the flywheel step height (.610) and I buy a branch new SBR street disc and slap it in. Now I have everything back together, but it is still extremely hard to put into any gear (at first the car had ALOT of trouble even starting) and it grinds badly. The pressure plate itself is stock. I replaced the throw out bearing and everything else that needed replacing. Why won't my car go into gear!? Maybe I should use an extended slave cylinder rod? Any suggestions would be extremely helpful. Thanks.

is this your first clutch job? did you bleed your clutch? did you torque everything to spec? did you have your flywheel resurfaced? have you tried adjusting your clutch? well ya gotta start narrowing it down a little for us, pin point every mistake you coulda made. as for the extended slave cylinder rod i dont think you will need it, but corrrect me if im wrong. its also a good idea to replace the slave cylinder and master cylinder, im not saying thats whats wrong but its possible. well goodluck to you......
-nick-

 

[Defiant]

The pressure plate itself is stock.

It needed replacing as well. No point in putting a fancy friction disk under a stock pressure plate.

 

[Ultimatedsm]

People always forget to do a few things when installing a clutch. You have to check for your pedal travel and freeplay, and adjust it accordling. This is very important! I hope you check those things out before you attempt anything.

 

[sonicnofadz]

is this your first clutch job? did you bleed your clutch? did you torque everything to spec? did you have your flywheel resurfaced? have you tried adjusting your clutch? well ya gotta start narrowing it down a little for us, pin point every mistake you coulda made. as for the extended slave cylinder rod i dont think you will need it, but corrrect me if im wrong. its also a good idea to replace the slave cylinder and master cylinder, im not saying thats whats wrong but its possible. well goodluck to you......
-nick-

No I have installed clutches on this car and on a few others. The flyhweel did not need resurfacing (recently resurfaced). The clutch line didn't need to be bleed (I never disconnected the line). The slave and master cylinder are new...however I didn't check the clutch pedal itself for adjustment...

 

[sonicnofadz]

It needed replacing as well. No point in putting a fancy friction disk under a stock pressure plate.

Fancy friction disc? It was only $100! I was just looking for a stock replacement but I heard alot of good things about this disc. The pressure plate looked fine, there were no bent fingers, the area where the throw out bearing engages has almost no wear, and it worked fine up until the old disc decided to come apart.

 

[DSMcrazy3]

One day, I blow my clutch disc up. I have extreme trouble shifting into and gear (grinds like crazy).

Sounds to me like a transmission problem then.. Bad synchros..Does it grind in every gear, even babying it into gear?

 

[Dream On]

I too would check the freeplay. Weld the pedal assembly if you need to. It sucks and I hated doing it, but I'll never have to again (at least on this car...)

http://www.dsmtuners.com/forums/showthread.php?t=156805
http://www.dsmtuners.com/forums/showthread.php?t=96981

 

[sonicnofadz]

I think an extended slave cylinder rod and or clutch pedal adjustment should do the trick. I remember now that the old clutch disc was very worn and I noticed when the pressure plate was tightened down all the way the fingers stuck outwards towards the transmission quite a bit. Now since the clutch disc is brand new, when I tightened the pressure plate I noticed the fingers don't stuck out at all, at it is pretty much flush. With this in my mind, I think an adjustment in the clutch fork travel is needed (the fork would need to be able to travel much further towards the flywheel in order to properly disengage the clutch). I also remember that as the clutch pedal was before, it was disengaging right off the floor (I had to press it all the way to the floor), so with all of these factors in mind, I think I just need to adjust the pedal and maybe use a longer push-rod on the slave cylinder....hope this works! I really appreciate everyone's suggestion...I sure hope my tranny hasn't bitten the dust. Before all of this happened it was shifting beautifully!

 

[sonicnofadz]

Sounds to me like a transmission problem then.. Bad synchros..Does it grind in every gear, even babying it into gear?

It was shifting fine in ALL gears, then after one launch (around 7000 rpms) I heard a really loud noise, and noticed I couldn't shift into any gears. After removing the transmission I found the friction disc had seperated (all the springs were missing too). I am HOPING that it is the disc the was causing the shifting trouble and not my transmission dying... However even after replacing the disc, I now cannot shift into any gear, but hopefully some pedal adjustment will cure me.

 

[Morphius]

I think an extended slave cylinder rod and or clutch pedal adjustment should do the trick.

Longer slave rod does NOTHING for getting more travel out of the system. Your clutch pedal assembly provide a defined travel or 'swing'. For that defined swing, the pushrod on the master cylinder displaces a defined amount of fluid based on the bore diameters. The slave cylinder only responds to the amount of fluid displaced by the master cylinder. The slave rod is only along for the ride.

The reason the extended slave rod works for so many people is this: There is a compensation valve in the master cylinder that cuts off flow to the master reservior once the pedal is depressed a small amount. A lot of people, (including myself as I've done this by mistake) have adjusted the pedal enough (or the master cylinder pushrod out enough) that it his preloading the pedal, causing this valve to shutoff. The result is a set amount of fluid in the line. The system, when the pedal is release, can't readjust itself for clutch wear. Now, when install the extended slave rod, the piston in the slave can't adjust or move inwards towards. The extra length then adjust the TOB towards the pressure plate, sometimes resulting in a TOB that rides on the presssure plate constantly. Results, early failure to the TOB, damage to the pressure plate fingers due to constantly contacting the TOB. The disk can also wear faster because the hydraulics is now holding the pressure plate open. As a clutch wears, the slave rod will move deeper into the bore. Now, remember the slave can't readjust due misadjustment of the master cylinder and now holds the clutch slightly open. (ie why some notice a newer disk slipping)

Bleed the system for air.
Check for master/slave leaks.
Check the step height on the flywheel.
Check the pedal assembly for slop.
Adjust the clutch pedal per service manual.

 

[sonicnofadz]

Longer slave rod does NOTHING for getting more travel out of the system. Your clutch pedal assembly provide a defined travel or 'swing'. For that defined swing, the pushrod on the master cylinder displaces a defined amount of fluid based on the bore diameters. The slave cylinder only responds to the amount of fluid displaced by the master cylinder. The slave rod is only along for the ride.

The reason the extended slave rod works for so many people is this: There is a compensation valve in the master cylinder that cuts off flow to the master reservior once the pedal is depressed a small amount. A lot of people, (including myself as I've done this by mistake) have adjusted the pedal enough (or the master cylinder pushrod out enough) that it his preloading the pedal, causing this valve to shutoff. The result is a set amount of fluid in the line. The system, when the pedal is release, can't readjust itself for clutch wear. Now, when install the extended slave rod, the piston in the slave can't adjust or move inwards towards. The extra length then adjust the TOB towards the pressure plate, sometimes resulting in a TOB that rides on the presssure plate constantly. Results, early failure to the TOB, damage to the pressure plate fingers due to constantly contacting the TOB. The disk can also wear faster because the hydraulics is now holding the pressure plate open. As a clutch wears, the slave rod will move deeper into the bore. Now, remember the slave can't readjust due misadjustment of the master cylinder and now holds the clutch slightly open. (ie why some notice a newer disk slipping)

Bleed the system for air.
Check for master/slave leaks.
Check the step height on the flywheel.
Check the pedal assembly for slop.
Adjust the clutch pedal per service manual.

Thanks for the info! Tonight Im going to check to see if the clutch pedal needs adjustment. The flyhweel stepheight is .610 inches (which, according to RRE, is OK). The clutch line has no air in it (the pedal is very firm and I never disconnected the line). I am certain the master/slave cylinders are not leaking, because my clutch fluid is at the fill line, where it was since I replaced the slave cylinder 2 years ago. I'm going to try adjusting the clutch pedal, and if this does not work, I'll try replacing the master cylinder...god I hope I don't have to drop the tranny again ARGGHHHHHHH

 

[sonicnofadz]

Well I adjusted the clutch pedal, and it still grinded like crazy going into any gear. So I said the hell with it, and I took it for a spin. I noticed that as soon as the car began moving it was a hell of alot easier to shift and didn't grind at all anymore!? So strange...anyways the car seems OK but there are still some issues. Even when I have the clutch pedal pushed to the floor (and I have it in 1st gear) the car will start creeping forward a little, like the clutch isn't fully disengaged. I have the clutch pedal adjustment rod (the one that goes into the master cylinder) maxed out on the threads, so I have no more travel to play with. Any more suggestions?

 

[Mr4G]

take your trans back off and put a washer under the pivot ball. this should work.

 

[sonicnofadz]

Hmmm yes this might give me more travel, but the pivot ball is brand new! Why isn't the clutch disengaging? Oh well I'll have another look tommorow

 

[Morphius]

Be sure to adjust the pedal per the service manual. So the point of resistance when the pedal is pushed, is 1/2. If the pedal is stiff from the start, or can be depressed further than 1/2 before some resistance is felt, then readjust the master cylinder pushrod. The clutch should release around 1 inch to 1 1/2 inches off the floor.

If after this adjustment, the hydraulics still doesn't release, I'd suggest pulling your pedal assembly and welding it up. In my opinion, the pedal load for an ACT 2600 is so excessive that it's at the limits of the cross shaft of the pedal assembly. It simply deflects torsionally too much for that given load. If after doing this, it still doesn't work, I see two options.

1. As most people suggest, shim the pivot ball 2mm. What this does, is eat up the tolerance between the TOB and pressure plate fingers. Although not the best idea, it helps. The risk is that no one knows what that stackup tolerance is. Does the TOB end up riding on the pressure plate constantly? May or may not. If it does and you've adjusted the pedal assembly correct, it may ride against the fingers and spin the TOB constantly. Although not the best, it likely would be OK given minimal load. (ie pedal system adjusted properly)
Potential to wear out the TOB early.

2. If after all the adjustments, shimming and welding it still doesn't release, I'd suggest a different slave. The 1G AWD 3000gt slave is a smaller bore and will increase the TOB travel for the same clutch pedal input. The down side is a slightly heavier feeling pedal. It's nearly identical to the AWD DSM slave except it's not threaded on the mounting tabs of the body. You'll need two bolts and nuts.

 

[PieEyedPiper]

I'm far less experienced at transmissions than you guys are but I know, that when a tranny is dropped, that the fork is then out of contact with the salve push rod. Correct?
Well when I moved my push rod off of my fork I let air into the system without ever actually opening the system. Bleeding of course was the solution, but if I'm correct, which I may very well not be, how did you avoid letting air into the sytem during removal of your transmission?

 

[sonicnofadz]

Air should not get into the system if the slave cylinder piston never pops out (and leaks fluid everywhere). You can take the rod out without having to bleed the whole system over again.

 

[Amazin' Wasian]

i would still recomend bleeding the clutch, you would be surprised.....
-nick-

 

[sonicnofadz]

OK I am at a loss. I am going to try to bleed the clutch tonight and see what happens. The car is getting hard to stick into any gear again, and in 1st gear (when I am a complete stop) the car shakes VIOLENTLY when taking off (even when Im careful to slip the clutch a little). It feels the car wants to stall but my rpms will be 2000-3000 and the car feels like its about to fall apart (because of the shaking). I noticed when adjusting my clutch pedal that there are traces of brake fluid leaking from the master cylinder (old and dried). So maybe a defective master cylinder is the cause of this?

 

[PieEyedPiper]

If thats the case you most likely have air in your lines. Any leak will let air in old or new. Even though I still don't know how you let the slave rod extend without letting air into the system, it happens instantly.. from my experience.
Shaking and other odd behavior doesnt sound very characteristic of a leaky master though.

 

[sonicnofadz]

I have found out the root of my problems! I was bleeding my clutch line when I noticed one of the tranny bolts that holds the tranny to the block was loose. It turns out the little "ear" that has the threads on the block (near the slave cylinder) had snapped and fell off. So my tranny is flexing (because that bolt isn't there for support) everytime I press on the clutch. I was able to use a longer bolt to try to clamp onto what metal is left and it goes into gear nicely except when I go into first it comes undone and I cannot go into gear again (the bolt pops and becomes loose) Tonight Im going to drill a hole in the front engine mount and use a longer bolt to thread into it instead of the block, so that the tranny stays in place. I can't believe my block cracked!

 

[Dream On]

Eeek. Hope it works out man. Damn.