rayaapp2 Posted May 6, 2014 Share Posted May 6, 2014 Here is the run-down on my setup. early sbc 2 piece rear main seal Centerforce flywheel McLeod Friction disc OE pressure plate LT1 T56 transmission (96 camaro) Titon 1" master OE slave The clutch setup has 4000miles on it, and is impossible to get into reverse without shutting the engine off. It also acts like it isnt fully disengaging when the pedal is depressed fully through the other gears. This started happening recently! As in this setup worked fine until a few miles ago! So I figured Id clean the whole hydraulic system out and bleed it. I did that and still no change! Then I checked the adjustment on the clutch pedal clevis and it was set correctly! Here is where things became interesting. The TOB sounds like it is working properly and I can adjust the clevis on the pedal to nearly bottom out the TOB against the transmission... which leads me to think that the clutch has had a failure. I have not had time to pull the transmission out, but I dont have a lot of experience with these kinds of clutches and I am hoping someone here will read this and be able to tell me what kind of failure I am expecting to find and maybe the best way to address it. I did some googling and found similar problems where spacers were used, but that doesnt sound like a fantastic idea and Id be worried about slipping the friction disc and burning the unit up. 1 Quote Link to comment Share on other sites More sharing options...
SUNNY Z Posted May 6, 2014 Share Posted May 6, 2014 Unless you can see that the TOB is indeed doing its job, I'd suspect thats your culprit. Possibly a bad seal on the TOB. See any seepage or leaks? Quote Link to comment Share on other sites More sharing options...
rayaapp2 Posted May 6, 2014 Author Share Posted May 6, 2014 (edited) The Throw Out Bearing on this is the pull type not the push type like the LSx setups. So there is no seal to leak at the TOB. The Slave is external to the bellhousing. And there are no leaks or seepage signs. From what I read this problem happens when the friction disc is too thick or either the TOB collar that the clutch arm attaches to fails/clutch arm pivot T fails. I have full movement up to the clutch arm and I can over adjust the clevis at the clutch pedal to get the TOB to bottom out(which makes me cringe a little) and still it does not dis-engage. This clutch setup has a mere 4000 miles on it, and it worked perfect until recently. Im going to order up a pressure plate and friction disc and have them on hand for when I take it apart. But since I do not have a lot of experience with this type of system Im having a hard time grasping the failure... Hopefully its something easy and cheap to replace being as I have so much money into this clutch setup already! Edited May 6, 2014 by rayaapp2 Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted May 13, 2014 Share Posted May 13, 2014 I warped my flywheel right after my swap by letting it out slowly at the drag strip thinking I was being easier on the axles. (Cooked that sucker). The warpage made it seem like my clutch disc was extra thick and it wouldn't disengage fully. I now let it out fast. If you've been driving that way, perhaps you have the same problem, so good-on-ya for having the parts on hand. I also recommend proving the operation of your clutch master cyl. Put a plug in the outlet hole (isolates the master). The clutch should be solid as a rock. Then put light pressure on it see if it leaks down slowly. My Tilton was brand new and it was bad-plugging it found the hydraulics problem. In other words, I had two reasons for similar symptoms. Funny, I have fantasized that the external hydraulic system of the LT/T56 was somehow easier to deal with. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted May 13, 2014 Share Posted May 13, 2014 That's just my experience, a single experience. Intellectually, it seems like you have something broken in the pressure plate. Quote Link to comment Share on other sites More sharing options...
egzlilgituarboy9 Posted May 14, 2014 Share Posted May 14, 2014 Ive had many problems with a similar setup. Check your throwout bearing and if bad replace with a lt-4 one much stronger, check your clutch fork pivot and clutch fork itself could be bent, also inspect your pressure place could have cracked or something along those lines. Your best bet is to pull the trans and inspect. it does suck but you gotta do what out gotta do. Had mine out 3 times in the last six months and i have to pull my motor to get mine out! Quote Link to comment Share on other sites More sharing options...
Rob240z Posted May 15, 2014 Share Posted May 15, 2014 About a year ago I was having the same problem with my car. I was able to max out the slave throw at first, but within a few days it started not wanting to fully disengage again when I was away from home. Within a few more miles it wouldn't disengage at all. After I had the car towed home I pulled the transmission and clutch. One of the springs in the clutch hub broke and came out. The spring lodged itself between the center of the flywheel and clutch. It never sounded like anything broke. There was no weird noises. I resurfaced the flywheel and put in a new clutch and it has been fine since. That was my experience, yours might or might not be the same. It could also be the clutch fork pivot. A bad throwout bearing will usually make noise when you push the clutch pedal down, but the clutch fork might have come out of it's place where connected to the throwout bearing. Once you completely rule out the hydraulics as a possible problem you need to drop the transmission and inspect everything. Good luck. Quote Link to comment Share on other sites More sharing options...
rayaapp2 Posted May 15, 2014 Author Share Posted May 15, 2014 Wow. thanks for the input folks! Gotta give Hybridz some time to respond back. My clutch came in yesterday so I put it on the rack this morning and pulled everything. I found that the clutch fork is hitting the pressure plate! The flywheel doesnt seem to be warped, but Im having it surfaced in a few hours. The friction disc looks fine. Other some heat scoring so does the pressure plate. Im replacing them anyway, because its out and I have the parts so why not. Right now though I am concerned about the clutch fork and T pin. Is my T pin the wrong size? The clutch fork looks cast... I would not think that it could "bend" before it would snap. Its almost like the T-pin is to long? Let me know if the pictures show up. Quote Link to comment Share on other sites More sharing options...
rayaapp2 Posted May 15, 2014 Author Share Posted May 15, 2014 The TOB itself doesnt look great. The bearing is smooth in action, but its oscillates a little. Quote Link to comment Share on other sites More sharing options...
NewZed Posted May 15, 2014 Share Posted May 15, 2014 Aren't the rub marks on the wrong side of the fork pivot point for what your problem is? When you press the clutch pedal you move that part of the fork away from the pressure plate, if the pivot point is where it appears to be. Looks like collateral damage, but not the cause. Quote Link to comment Share on other sites More sharing options...
rayaapp2 Posted May 15, 2014 Author Share Posted May 15, 2014 No that side faces the pressure plate. I have the pressure plate turned around from the way it would be installed in relation to the transmission in the picture. Just got back from the machine shop. They took .020" off. There was a bit of warpage. So the old pressure plate is junk for sure with that kind of a deal... it will chatter if I try and use it again, but it is a stock pressure plate. The new pressure plate is another GM unit... its amazing how many places use the OE pressure plate for this setup and re-brand it, but it has all the factory casting numbers on it! I bought a "HD" friction disc. The old McLeod friction disc had ceramic pucks on one side and the other side looks like regular clutch material. The new one isnt ceramic at all. Quote Link to comment Share on other sites More sharing options...
NewZed Posted May 15, 2014 Share Posted May 15, 2014 I understood the picture. The rub marks will only happen when the clutch fork for is unloaded, that was my point. When the fork is just hanging there. When you press the pedal the end of the fork that has the rub marks moves away from the pressure plate. Quote Link to comment Share on other sites More sharing options...
rayaapp2 Posted May 16, 2014 Author Share Posted May 16, 2014 No, the contact only occurred when the pedal was full depressed. As Rebecca pointed out the flywheel can warp...well it was warped and on that end of the clutch fork as you depress the pedal it moves toward the pressure plate as it is on the outer end of the pivot point. I double checked the clearance before I fully assembled it this time. It turns out between the warpage and the TOB being wasted that created my problem. Everything seems good with the new clutch in on my test run. Matter of fact the transmission shifts easily into all gears and better into reverse than it ever had before! I ordered up some new tie rod ends and next Im getting an alignment then its off to see what autox events are coming up! Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted May 16, 2014 Share Posted May 16, 2014 Yippee! Happy for you. Pulling that tranny and bleeding everything is a real chore. And you got to it quick! I bet you can still be smooth in traffic if feathering at low rpm, but if you are launching with the revs up, let 'er out quick. I warped mine my first season, but had no trouble all last season at all since changing my technique. Axles and driveshafts are another matter... I keep spares for that now. We are gonna break stuff if we dog these old cars out-best to break the stuff that is easy to get access to. Build in such a way that you can fix stuff as easy as possible. Quote Link to comment Share on other sites More sharing options...
NewZed Posted May 16, 2014 Share Posted May 16, 2014 Good that it's fixed. I guess I don't understand how the pull-type LT1 linkage works. I thought the fork was getting pulled, but it must be the TOB, pulling on the diaphragm spring fingers. Kind of odd. Thanks for not getting all uppity on me. Quote Link to comment Share on other sites More sharing options...
rayaapp2 Posted May 16, 2014 Author Share Posted May 16, 2014 Im running the z31 turbo cv axles. Nice and thick with the large ball cage. I only worry about the 29 spline outers and my drive shaft u joints on this car. I have a VLSD that could also be a weak point, but when it goes out... its just an open. NP NewZed. Yep that is exactly how it goes together! Odd yes, and why it was done that way and not made to be simple like the RB25 or VG30dett I dotn know cause that clutch setup is plenty strong and simple. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted May 17, 2014 Share Posted May 17, 2014 Sounds like a porn star. Quote Link to comment Share on other sites More sharing options...
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