RebekahsZ

Been waiting all morning for your post. Ouch. I never dreamed we'd be breaking there. So you were able to drive home on 1 axle because you are welded? Any oil left in your diff? Looks like I'm goon be setting my 2-step at 2000 and leaving it there. I'm so super bumbed for you. If I'm gonna have to keep the launch rpms that low (so much for the bias ply theory (how much air you inflatin' to)), that opens things up for some drag radials to make the fast end safer??? When you gonna start your 9 inch conversion thread? Once I get my 7.0 I may slap all the camber back in it and lean more toward going around cones.....the amount of maintenance it takes to drag race one of these cars....

I replaced the 7/8" defective Tilton master cylinder with a new 1" Tilton master cylinder and I think my problem is solved. Car is shifting really slick-ly. I haven't tried it at 6,000rpm because I haven't logged the recommended 500 miles of easy driving for breaking in the clutch. That will be a better test than the driveway test (it always passes that one). One thing that is cool about this ceramic clutch is that I can HEAR when it starts to engage. But the true test is no shift refusals at 6k rpm. Drove car for about 4 hours today of mixed driving styles from city to highway and it was just great. I'm so very happy. I DO want to shim this thing to improve my pedal/clutch engagement position. I have some ordered. What thickness did you use? My clutch provider insists that I shouldn't need a shim, but I do. Thanks so much for your help/advice.

You are always one step ahead of me! I have all the parts for the clutch-mounted MSD 2-step, but this damn clutch held me up! Send pictures of your install if you can. I think I have the clutch under control now. It seems to have been the master cylinder.

Looks like the problem was the master cylinder. Talked to Dan at Tilton who gave me a really simple trouble shooting plan. Put an AN3 plug in the master cylinder outlet and that isolates the problem to the master cylinder. Did it and problem continued-see videos. Swapped master cylinder and everything seems ok in the driveway. Unfortunately going from a 7/8" master to a 1" master makes for one very stiff clutch. Will adjust throw tomorrow, will have to be careful not to overextend slave. If this doesn't fix it, I have slave cylinder shims on the way. Had a really tough time getting all the air out of the new master in order to bleed the system by the traditional methods. Finally, used SUNNY's technique of mighty vac sucking on small hole in the master cylinder reservoir - that is what finally got the job done. I kept vacuum down below 5, just in case this is what ruined my old master. Then, very brief bleeding of lines by putting the remote speed bleeder into the reservoir. Tore old master down and I don't see anything wrong, which worries me a bit. Just watched videos, note that they are not before and after. They are before swapping in the new master: one time I push the clutch and no disengagement, next time it disengages fine...it has been the unpredictability that has been killing me. IMG_0733.MOV IMG_0734.MOV

Is that the stock clutch pedal? It looks like the arm is just as thick as the brake pedal...my clutch pedal flexes a good bit, hmmm.....

I gotta get my google translate to help me with that video! Great work y'all.

SUNNY, I called YOU, remember? I wanted the phone number for the hot chick with the green hair, but I got you instead. I have no advice for anybody until I get this pathetic clutch fixed. (sad face).

Please do a super detailed writeup on the supercharger; this is on my list. Subscribed.

An easy way to see if you are bottoming out is to put a long bread-tie type twisty tie around the strut rod and see how much it gets pushed up. Kind of a "tell-tale."

Call it "patina" and keep driving it.

Start swapping diffs and burning up clutches and you'll be dropping that driveshaft several times a year. Plus, I make a habit of re-tightening my driveshaft and axle bolts after every trip to the track. Anything that makes removing it easier is well worth the initial trouble. I just wish there was a good way to get a torque wrench on the bolts. I LOVE my RT mount. I think the way you lowered the rear of the diff was genius: the easy solution is usually the best! Congrats. I wonder what grunts and grumbles will be uncovered when I finally put a muffler on my beast-I may be copying your fix.

Sorry about the omission, and thanks for the advice, I'll take all I can get. New 7/8" Series 74 Tilton MC. Same MC as a Tick (see LS1tech.com). Had a brief, but good talk with Tilton rep: Dan. He had a simple suggestion: put a plug in the end of the master cylinder and see if the pedal acts the same way. Plug on order via Speedwaymotors.com. The black hydraulic fluid comes from the way the throwout bearing/slave is designed (it sucks clutch dust)-it is a universal LS-style T56 problem. My fluid started to blacken on my first test drive, but I've already flushed it once and will flush it before each trip to the track. I chased the black fluid poltergiest around for weeks before replaceing the clutch (which was warped). Seems black fluid and frequent flushings are just going to be part of my LS hotrodding experience, but it doesn't seem to hurt performance. Went ahead and ordered a 1" Series 74 Tilton from Summitracing.com along (couldn't find a 15/16" anywhere) with a puke bottle for my R200 which spits a little out of the vent tube. There was this Mustang at the track with a leaky diff that was really making work for the track crew everytime he lined up. They were nice, but I'd have been pissed. My replacement parts should be in this weekend and I'll find out if it helps. For all I know, I hurt some internal seal with my mighty vac.

That would make me very sad with only 18,000 miles on it.

I have been all over LS1tech.com and have tried every solution offered. In fact, I did everything they recommended before I installed the new clutch. I'm calling Tilton now regarding the bleed-down of the pedal with constant, light pressure. I searched there more than I did on this forum, but since then I've found several guys on our forum: ULLYSES, EvilC, cheesepocket and others who have fought this, but they haven't volunteered any solutions. Theres were old posts, so maybe they have moved on to more interesting topics. What kills me is that when I first did this swap, the clutch was super sweet, even with just a 3/4" master. If tilton has nothing to say, I may just swap back in my 1" to find out if more volume solves the problem. I've learned something from every mod I've made, so I just haven't found the right needle in the haystack.

Super bumbed out. I just can't seem to get the performance I need from my clutch hydraulics. I've replaced EVERYTHING in the system and I still don't have this right. Clutch is disengaging only when pedal is absolutely on the floor, and it is not disengagine enough to allow for hig power shifts. Sometimes at intersections, I have to pump the pedal several times to get it to work. Everything is new from the master cylinder to the flywheel. Re-bled the master cylinder (no bubbles). Used a mighty vac inside the master and at the end of the bleeder: no bubbles. I have bled the rest of the system for about 30 minutes continuously by putting the remote (speed bleeder) bleeder in the fluid reservoir so that the system re-fills itself. Pumped pedal smoothly for 30 minutes. Even switched fluid from yellow Motul to blue ATE Super Blue to ensure that I was pumping fluid well-no bubbles at any point in the process. The new throwout bearing is only moving about 1/2 inch inspite of having maximum adjustment of the pedal linkage. It would take 1" to fully extend the thowout bearing, so I'm nowhere near overextending it. At first, I'm thinking that the Datsun pedal doesn't allow for a long enough stroke of the 7/8" master cyl, but the push rod pin is 2" from the pedal pivot in the Datsun, whereas it is about 1-1/4" from the pivot on the 3/4" stock GTO master cylinder. Also, if I push the pedal quickly and firmly (it is firm at the top), I get good feel and the clutch disengages (barely), but if I slowly apply light, constant pressure to the pedal, I can get the pedal to slowly go down almost all the way without very much pressure at all, and the clutch won't disengage. This is a new Tilton master cyliner. Anybody recognize any of my symptoms and have a fix? This clutch problem has sidelined me for about 2 months and I see no end in sight. I'm at the point of despair. Maybe I should adjust the top pedal stop to keep some pre-load/pressure on the master cylinder to keep the piston from bottoming all the way out in the depressurized position? That is my next step...

All great ideas are rejected initially. You know going to coilovers makes it impossible to go back to stock springs and citing out the tyranny mount makes going back from a v8 to an L6 impossible too. Good job.

You ought to sell those brackets!

I have had same problem, there are a lot of posts out there from me and a bunch of guys helped me with advice. Mine is a R200 Z31 CLSD with 6 new clutches and 4 shims for a tested preload/breakaway torque of 63 pounds wet. I still have an occasional pop/bang and shudder but it is much better than when I first did the mods. First thing to do is take car to a parking lot and do circles clockwise for 15 minutes then counter clockwise for 15 minutes. Turn as tightly as you can but not so tightly that it bangs. Yes, you will get dizzy and bored. This dramatically reduced my popping. I have no idea why it helped. If it bangs too much, drain off your diff. oil then refill after putting in 2 tubes of friction modifier. Filling diff. on the car is a real PITA. I was able in my 240Z to pull a drain plug in the spare tire well and run a 3/8" hose down to the diff. using a funnel at the top end. This winter, I plan to remove some shims to reduce breakaway torque. Hope that helps.

I really like the Subaru R180 CLSD swap using johnc's adapter flanges. You are looking at 400-500 for the diff and 500 for the adapters. You can reuse your driveshaft axles and mustache bar. The only "while you are at it" that I would do is the RT front diff mount which is about 70 bucks. This is a GREAT setup. I put 400 hp to it for several months and took it to the strip with street compound tires. I haven't put it up for sale for sentimental reasons but I have all the parts for this swap along with some really nice (but expensive) Wolf Creek axles, which aren't necessary to make the system work.

Not sure what you mean by "blew out" but the cheapest way to go is to fix what ya got. Next is another stock r180. If going LSD, save up a thousand bucks unless you get lucky and stumble into a real deal on the parts. The issue is that the "leg bone's connected to the - foot bone...." Depending on the year car you may have to change the driveshaft, mustache bar, and axles.

A picture is worth a thousand words. By the way, nice clean under-dash. I think my car has a few dead bodies tucked up in the under dash wiring!

The longacre camber gauge is really nice. Pu one on your Christmas list.

Look at my learning to drag race thread and you will find pictures of the bumpstops jnjdragracing recommended. Also, did you use progressive springs? They coil bind really bad and that feels just like bottoming out. Simple way to find out if coil bind bumpstops orbottoming out is the problem is to raise ride height and see if problem goes away. Actually coil bind could continue even still. That can be seen by jacking car up by by LCAs with tire off.

In an unrelated situation (hydraulic clutch), I'm having trouble getting all the air out of my system. Does the cylinder need to go FULL stroke to purge all the air? I'm not getting bubbles anywhere but pedal still is good at times and soft at others. I can't understand why I could have such intermittent performance. It is totally unpredictable. Any ideas?

Sure I'm taking calls, but honestly nobody has ever called! Everybody has a different take on the build but by now we ought to have a cook book. I would have loved more guidance on the wiring but that was where the least help was forthcoming. I bet there are a bunch of conversions out there with everything done BUT the wiring. I'll be happy to help where ever I can. I'm still having trouble with intermittent clutch failure to disengage.