One step closer to selling it.

[Luke]

Hi CP:

Not sure if you already aware of this, but the stock clutch master cylinder has a built-in self-adjusting mechanism.
For the self-adjusting to work ( for example, your pedal engagement should not get higher as the clutch disc worns out and becomes thinner ), there need to be some freeplay at the top of the clutch pedal.

Instead of keep screwing the clutch rod in the direction of *into* the master cylinder, try backing it *out of* the master cylinder, until you get some freeplay at the top of the clutch pedal. Maybe that will get the self-adjusting-mechanism working properly. It did for me...

 

[CP]

Thanks guys. All great comments. I'm pulling the trans tongiht and will see if I've got clutch issues when it comes out. I've got a bad seal on the input shaft (I think) anyway, as I've had some fluid seepage from the shift fork boot hole in the bellhousing for about 6 months now.

 

[iceman69510]

Well, sorry to tell you this, but the input shaft seal has to be replaced from inside the trans.

 

[CP]

It's probably going back to Shep for an overhaul in the winter anyway. If the trans swap solves my driveline issues, then it's definitely the center diff. That's mostly the reason for the trans swap tonight. If that doesn't solve it, then I'm out of ideas, having already rebuilt the rear diff, driveshaft several times, and tried 3 different t-cases.

 

Quoting olson:
CY ive been going through the same problems but to an extream. i have a fidanza fly wheel and a 2900 act setup . after doing some pulls and dataloging the clutch let go. the friction center section completely let go. the cause was an over throw of the clutch pedal be extreamly carefull to not get to much throw other wise the pressure plate fingers will come in contact with the friction plate. i guess this is a common problem with the act seires clutches. so i went with an exedy unit and the fidanza fly the problem just started to come back i could HEAR the fingers making contact with the center section. also the fly wheel warped on my. At this moment im putting in a RRE no name 11lb flywheel. Also prior to putting in the exedy i replaced the slave and master and put an a extended rod on the master cylinder fixed the problem but had to much throw. also i think the fidanza flywheel wasnt steped right for the setup i had. My pedel box is the orginal one but has NO play in it at all. so hopefully the correct steped flywheel and all fresh clutch compnets are good. Also have a braided line with a teflon coating on it that was pressure tested at some crazy # .





The problem is called "over center" and it is caused by the clutch having too much pre load and causing the diaphragm fingers on the clutch to go past the center point and collapse on the disc. Not a very common problem on any ACT clutch or Exedy one unless the clutch isn't adjusted properly. If I have the rod on my car adjusted too far out I can make the springs touch the diaphragm every time I push the pedal in.

Every Fidanza flywheel I've ever seen has always had the correct step for DSM's/VR4's. So unless they've changed how they make the flywheels or have a bad batch I don't see how that would be an issue. What is more likely to have happened is as a result of the preload condition is the following: the preload condition on the clutch would have caused the disc to drag on the flywheel and pressure plate because it's the same as driving around with your foot on the pedal constantly. Eventually the heat generated from that would cause the flywheel to warp.

Daryl

 

[blacksheep]

^^^^ mahboie Daryl working for ACT knows his shizz....

 

[CP]

Soooo...it appears that my transmission has been porking me slowly for the last year or so. My "leaky t-case" turns out to be the transmission.

Inside the bellhousing:

Welp, the pic poster seems to be fubar'd right now.

The inside of the bellhousing is coated with black trans fluid. My "red" ClutchNet pressure plate is black and somewhat tacky with burnt/dried transmission fluid. I haven't popped off the clutch yet, and don't really want to for fear of having to replace it.

The clutch fork is fine. The pressure plate fingers are all there and intact/not loose. I still don't know what the problem is with the hydraulic system, but am going to replace the master cylinder.

I'm willing to bet my center diff is bad, and will find out after 1/8 mile once the spare trans is installed in the next few days.

Frank's putting up a fight, but I'm going to win this one /ubbthreads/images/graemlins/mad.gif In the meantime, the race car isn't all that fun to commute in. I got pulled over on Friday coming home from work for "speeding" and got a warning, and some questions about the LOUD exhaust. Fun stuff...

 

[curtis]

Cy

Hate to tell you this but while your down there and everythings off pull the fracking oil pan and change the thrust bearing or at least get the pan off and use a feeler gauge. I beat your thrust is gone and its crank walk city. With everything off you could change the rod and all the mains at the same time.

I had the same problem and didn't do it cause of time then it destroyed a PTT dual disk disks and has the car pulled apart for an insane rebuild restoration. 2 years coming in January so I haven't driven it in to damn long.

 

[CP]

More details! Do I need to push this thing in front of an 18 wheeler?

 

[ktmrider]

Ah yes Curtis, that does sound like the symptoms of crankwalk.
From what I read on the 7 bolt engines the usual problem was not oiling or noise but notchy/hard shifting, especially around corners.
Cy, check out the DSM boards for more info and if the issues match yours.

 

[CP]

Nah, I'm in denial. I just need to get this thing back on the road for now. I'm going to clean it up this afternoon and have some buddies coming over to help me get the other trans installed this evening.

 

[CP]

Is there any way I can check for crankwalk without opening up the bottom end, like pulling/pushing on the flywheel to see if it moves in/out at all?

I have zero experience messing with any parts in the block, and don't have any desire to learn this summer unless absolutely necessary.

 

[Rausch]

Yes (Ask me how I know...) I did it with the trans still in the car. you could see the crank pulley move when stepping on the clutch.. I was able to have someone step on the clutch and move the crank back with a small pry bar..I would assume you could do the same with some leverage on either side, and try to shift it back and forth. I don;t know the spec., but if it moves more that a TINY bit (couple thou) I would replace the thrust bearing.....

Mine was easy to diag., as when I stepped on teh clutch, the car stalled. /ubbthreads/images/graemlins/crazy.gif

 

[CP]

Got a diagram of where the thrust bearing is located, or a page number in the FSM?

From killing me slowly to killing me quickly...

 

[atc250r]

The thrust bearing is the middle main bearing set.

 

[CP]

I yanked on the flywheel but couldn't tell if it was moving in/out or side to side just a tiny bit. I'll be buttoning up the trans over the next several evenings and then will deal with this possible crank issue. It's back on the engine now. Hopefully the spare doesn't have anything wrong with it.

I sure made a dust cloudy mess when I blew off the clutch with compressed air. The pressure plate needed SEVERE cleaning with engine degreaser and brake cleaner. However the disc had barely any trans fluid on it from what I could see.

 

[atc250r]

Don't blow that sort of stuff with compressed air, that dust is really bad for you. Just spray it down thoroughly with brake cleaner. Don't use engine de-greaser or carb/t-body cleaner as those leave an oily film behind.

John

 

[Barnes]

Quote:
Don't use engine de-greaser or carb/t-body cleaner as those leave an oily film behind.



Really?? Never noticed myself.

 

[atc250r]

Yup. The other two are normally petroleum based, brake cleaner isn't. They don't leave much of a residue but when it comes to brakes or clutches I wouldn't want to roll the dice with either of them.

John

 

[Barnes]

Oh. Duh, I just automatically lump brake cleaner into the de-greaser category. I almost exclusively use brake cleaner.