Determining if slave cylinder needs a shim

[KDT]

I recently installed a new Exedy Mach 600 clutch and p.p. in my car. I also installed a new slave cylinder when I replaced it even though the car has only 8K miles on it. My stock clutch was slipping pretty bad, especially in 3rd gear at wot. I used a new take off oem flywheel instead of an Exedy lightweight flywheel. I really didn't want a lightweight flywheel and Exedy doesn't make one in standard weight. Well after the 500 mile break in, I noticed a slight grind if I shift into 3rd fast. I have a WOT box and it grinds at any rpm if I shift it fast. It only does it going into 3rd. All other gears are fine and if I drive it normally, there is no hint of a problem. I didn't notice any grinding before the clutch install but it was slipping pretty bad. About a week before I put the clutch in I missed third really bad and very well could have damaged something in the trans then. I didn't try another fast shift until the new clutch was in it. I very well could have a problem in the trans with the 3rd gear syncronizer but I want to be sure it isn't something to do with the new clutch before I order the parts to rebuild 3rd gear. There has been some discussion in other threads about shims being used under the TOB to get the clutch engagement correct in certain applications. I surely don't want to be guessing here. I went out this morning and jacked the car up. I checked the clutch engagement with a tape measure using the clutch pedal for a reference. With the clutch all the way to the floor and the car in 1st gear, I can ease the pedal off the floor and the rear tires start to move with the pedal 3" off the floor. The clutch pedal is 7" off the floor at the top. There is exactly 1" off "freeplay" at the top. With my foot resting on the brake just enough not to stall it in first gear, the wheels stop turning as I push the clutch down to the same 3" mark. That's exactly half way of the pedal travel minus the "freeplay". Does it need to engage a little more off the floor? I would hate to get in there and find nothing wrong and discover that all I needed was a shim. Any input at all would be appreciated. I am coming back out with the trans this week and surely want to get it right this time.

 

[KDT]

Well I got the trans out and disassembled. There is nothing wrong with third gear or anything else in the trans. The syncronizer, the gear itself, and the blocking ring look brand new. I went ahead and put it back together and ordered an Exedy flywheel and a .150 slave cylinder shim. I really didn't want a lightweight flywheel but I will take it if it stops the 3rd gear grind. I am determined to fix this shit. If this doesn't work I will put a damn automatic in it.

 

[GrnBullitt08]

Let me know if that shim helps. I have been having similar issues since I installed my Spec Clutch.

 

[KDT]

I guess I will try it with the new flywheel first. If it still doesn't work right. I pull out the trans and put in the shim. If that doesn't work I will pull the trans out and bury it in the back yard and put a built 4R70W in it.

 

[rojizostang]

well if you're going to bury your transmission, let me know, i may come dig it up and send it to liberty or somebody and have them fix up nice.....maybe that's what you should do to start with?

 

[GrnBullitt08]

Im sure the built 4R70W will work a little better with your setup anyway. I plan on putting a T-56 V-Spec in mine.....but first Im gonna blow mine up.

 

[KDT]

well if you're going to bury your transmission, let me know, i may come dig it up and send it to liberty or somebody and have them fix up nice.....maybe that's what you should do to start with?

Liberty can't fix something that's not broke. There is nothing mechanically wrong with the trans. I determined that today. Its got to be something to do with the tolerance in the clutch and slave. I really don't want to put a lot of money into a 3650. I would rather put that 2 grand toward a 6060 or better yet a T56 Magnum. Now that I have seen the internals of this trans first hand, I like it even less. All the gears look pretty strong but the design of all the shift gates and linkages are crapy imo. Now I know why it is so notchy.

 

[1fastpony]

If you are having shifting issues at WOT have you thought about first replacing the plastic hydraulic line with a steel braided one. I did and you can feel the difference in normal shifts and WOT. If you haven't it might be worth the time and effort.

 

[KDT]

If you are having shifting issues at WOT have you thought about first replacing the plastic hydraulic line with a steel braided one. I did and you can feel the difference in normal shifts and WOT. If you haven't it might be worth the time and effort.

I put the JPC line in when I replaced the clutch and yes it does make a noticeable difference. I am now almost positive that my problem has to do with tolerances in the clutch and slave. That's pretty much all that's left now.

 

[KDT]

Well, I found the problem. I have a twisted input shaft. I tried to slide the clutch disk down the splines and it will not go very far. I then put a straight edge on one of the splines. You can easily see that it is twisted, probably a couple of thousandths end to end. Problem found, now I have got to figure out what I am going to do.

 

[GrnBullitt08]

Shit, I hope that's not my issue.

 

[KDT]

Just found it while ago. My cash is low right now but I have got to fix it.

 

[GrnBullitt08]

I'm planned on adding a new shifter, k-member brace with torque limiters, steel clutch line, and changing the fluids and see how it runs.

 

[KDT]

Good luck. I hope that works out for you. I am self employed and business is bad slow. I sure didn't need this right now. Oh well, at least I found the problem. I guess it is time for an upgrade, hopefully I can swing it.

 

[GrnBullitt08]

I'm partially self employed myself and I feel your pain. Finding work has been rough, my other job has been supporting me lately.

 

[rojizostang]

not to beat a dead horse, but liberty quoted $650 to upgrade the input shaft and polish all the shift forks and shot peen the synchros and stuff. maybe that's an option if you're not going to swap to an auto or go to a 6 speed.

there were a couple of other places that do upgrades for the 3650 also, but i don't remember who they are except for maybe hanlon motorsports i think. good luck

 

[KDT]

not to beat a dead horse, but liberty quoted $650 to upgrade the input shaft and polish all the shift forks and shot peen the synchros and stuff. maybe that's an option if you're not going to swap to an auto or go to a 6 speed.

there were a couple of other places that do upgrades for the 3650 also, but i don't remember who they are except for maybe hanlon motorsports i think. good luck

Thanks for the info, I plan to make some calls today. Liberty is on my list.

 

[KDT]

Thanks again for putting me on the right track rojizostang, I just got off the phone with Liberty. I am shipping the trans to them for a carbon syncro and 26 spline input shaft upgrade. With shipping and everything I should be looking at about 6 to 7 hundred. I can sure handle that. I have just got to find a new 26 spline clutch disk now.

 

[rojizostang]

Thanks again for putting me on the right track rojizostang, I just got off the phone with Liberty. I am shipping the trans to them for a carbon syncro and 26 spline input shaft upgrade. With shipping and everything I should be looking at about 6 to 7 hundred. I can sure handle that. I have just got to find a new 26 spline clutch disk now.

hmmmm......did they say anything about a hardend 10 spline shaft? i have someone making me an offer on his transmission out of his 2010. i'm still thinking about picking one up and having it upgraded and holding it in reseerve until mine goes DOA. Now i wish i had mine sent out while the clutch and slave cylinder job was being done...

BTW...gotta give credit where it's due...US-1 turned me on to liberty...it wasn't an idea of mine

 

[Ken04]

Liberty can't fix something that's not broke. There is nothing mechanically wrong with the trans. I determined that today. Its got to be something to do with the tolerance in the clutch and slave. I really don't want to put a lot of money into a 3650. I would rather put that 2 grand toward a 6060 or better yet a T56 Magnum. Now that I have seen the internals of this trans first hand, I like it even less. All the gears look pretty strong but the design of all the shift gates and linkages are crapy imo. Now I know why it is so notchy.

it's not the trans I think in your case or mine, although I thought it was for awhile. It's the clutch release and engagement. I have a very similar issue in a stock clutch and TR3650. I can push the clutch pedal in between shifts and it's doesn't completely disengage which makes it also grind at times going into the next gear. And the only way I discovered it wasn't disengaging properly coming out of gear is hearing the driveshaft clunk around. If I pull it out of gear without the clutch the driveshaft doesn't clunk.