Determining if slave cylinder needs a shim

[rojizostang]

/\/\he has a twisted input shaft...

 

[Ken04]

/\/\he has a twisted input shaft...

I do ? Or the OP ?

 

[rojizostang]

the op twisted the input shaft. see post 10

 

[GrnBullitt08]

Good info on Liberty, I'll be looking that way first as well before I go dish out $4,000-$5,000 for a new T-56

 

[KDT]

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

I immediately liked what I heard from Liberty's. Out of all the tranny shops I talked to, I liked them the best by far. My trans is in route to them as we speak. I have heard of a hardened 10 spline shaft but at this point with everything that I have been through, I am going 26 spline. I got a new clutch disk and flywheel also ordered today. Thanks again for setting me straight. Damn, if you weren't so far away I would buy you a 24 pack.

 

[rojizostang]

I immediately liked what I heard from Liberty's. Out of all the tranny shops I talked to, I liked them the best by far. My trans is in route to them as we speak. I have heard of a hardened 10 spline shaft but at this point with everything that I have been through, I am going 26 spline. I got a new clutch disk and flywheel also ordered today. Thanks again for setting me straight. Damn, if you weren't so far away I would buy you a 24 pack.

thanks, but i really can't take any credit. i did speak to them on the phone, but SD turned me on to them. i'm just wishing i had made this move already. oh well

 

[bigray327]

So back to the original topic, does anyone have any tips for knowing when you need a shim? My XRT/6060 combo chatters like crazy, and I think the TOB is either going bad or needs something.

 

[1fastpony]

Great you got it figured out. Now from your clutch release discussion you got me thinking. With a hydraulic clutch shouldn't the release point be at the same point regardless. I'm scratching my head. I know mechanical types you'll see/feel the release point change as it wears out, to the point of the clutch being on the floor and not disengaging the cltutch from the flywheel.

The last six months since my centerforce failed the car would walk on the starting line when reving high rpms and eventually failed. Installed the Spec and it seemed ok during normal driving but going through the gears hard the cltch pedel would get awfully light. Then reving the car high rpms with the clutch engaged the pedel would instantly get soft and drop...then the clucth would seem to slip but no smell. a coinsidence the brake pedal would also get a little mushy. Often the pressure, force on both pedels to engage would be different. So thinking it might be the slave cylinder I ran it across a local speed shop here in town, Alternative performance an ADRL shop. The free adivse was "It sounds, feels, smells like an hydraulic issue possibly a vacum issue since it would take a few pumps of the brake pedel to firm it up during normal driving. A week or so ago I check the master cylinder and booster and there some good evidence of leakage, changed both out and now both pedels are very firm. The only test now ist to put the stickys on, rev it up, and let'er rip and see if the cltch holds up.

There are so many similiar symptoms to tranny and clutch problems I just wanted to get my case out there for those here to be aware of.

Hope your problems get worked out. Mine seem to be coming together and the car is ready hopefully, for a few more passes down the track...the car sure feels strong now. Hell, a vacum leak can cause all kinds of problems with the car and not even throw a code.

So back to the original topic, does anyone have any tips for knowing when you need a shim? My XRT/6060 combo chatters like crazy, and I think the TOB is either going bad or needs something.

My spec chatters just a bit when slowly releasing, don't think yours is suppose to. Try pulling a vacum on it and see if the symptoms change. DO you have the Mcloud slave?

 

[KDT]

From this experience, I have learned that a shim behind the slave will change where the clutch engages and disengages. If it disengages too close to the floor then a shim is needed. But who knows how thick? Trial and error taking the trans in and out appears to be the only way. Fuck that! From this experience, even though I discovered that my input shaft was twisted, from now on if I change my clutch, I will replace the flywheel with a new one from the same manufacturer. That should reduce the chances of a shim being needed. In fact I went ahead and ordered an Exedy flywheel along with my new 26 spline disk just to reduce the chance further more. I also ordered a .150 shim just in case but god forbid if I need it...lol Even turning down a flywheel a few thousands has an effect. I guess if you were to measure the thickness of a flywheel that you know is correct for a certain clutch before it is turned down, you could remeasure it afterward and add a shim behind the slave that is the same thickness as what was removed. I believe that would be the only situation where you would know for sure before putting it all together. If the transmission bell housing had a big window in it where you could get in there to take measurements, you could probably shim it properly and only have to remove the trans one time to put the proper shim in. In other situations, I don't see any other way than that putting it all together and driving the car to check the clutch operation hoping like hell you got it right as the only option. If someone knows a better way to do it on our cars, I would love to hear about it.

 

[1FastS197]

From this experience, I have learned that a shim behind the slave will change where the clutch engages and disengages. If it disengages too close to the floor then a shim is needed. But who knows how thick? Trial and error taking the trans in and out appears to be the only way. Fuck that! From this experience, even though I discovered that my input shaft was twisted, from now on if I change my clutch, I will replace the flywheel with a new one from the same manufacturer. That should reduce the chances of a shim being needed. In fact I went ahead and ordered an Exedy flywheel along with my new 26 spline disk just to reduce the chance further more. I also ordered a .150 shim just in case but god forbid if I need it...lol Even turning down a flywheel a few thousands has an effect. I guess if you were to measure the thickness of a flywheel that you know is correct for a certain clutch before it is turned down, you could remeasure it afterward and add a shim behind the slave that is the same thickness as what was removed. I believe that would be the only situation where you would know for sure before putting it all together. If the transmission bell housing had a big window in it where you could get in there to take measurements, you could probably shim it properly and only have to remove the trans one time to put the proper shim in. In other situations, I don't see any other way than that putting it all together and driving the car to check the clutch operation hoping like hell you got it right as the only option. If someone knows a better way to do it on our cars, I would love to hear about it.

dammit... i figured that was the only way to tell...



oh and KDT... i don't know if Exedy is like spec but spec can resplined their clutches for 59 plus shipping... just seen where you said you was gonnna order a new one...

 

[KDT]

oh and KDT... i don't know if Exedy is like spec but spec can resplined their clutches for 59 plus shipping... just seen where you said you was gonnna order a new one...

Thanks! I was unaware that a disk could be replined. That's good to know. Exedy didn't even mention it when I talked with their tech support. Anyway, since what happened, I have rethought my clutch. I have decided to go back with a Mach 500 instead of a 600. The 500 disk has 20% less friction coefficient than the 600 so it doesn't lock up quite as fast. That should soften the hit up some. I still will have more than enough clutch for my power. The only difference between the 500 and the 600 is the disk. The pressure plate is the same. I honestly believe the 600 was overkill for my car. ( lesson learned) That may very well have had something to do with me twisting the input shaft. I'm telling you, that 600 grabs like a mofo. Well anyway, my new disk in on its way. It was a special order straight from Exedy. I also ordered their billet flywheel to go along with it.

 

[1FastS197]

Thanks! I was unaware that a disk could be replined. That's good to know. Exedy didn't even mention it when I talked with their tech support. Anyway, since what happened, I have rethought my clutch. I have decided to go back with a Mach 500 instead of a 600. The 500 disk has 20% less friction coefficient than the 600 so it doesn't lock up quite as fast. That should soften the hit up some. I still will have more than enough clutch for my power. The only difference between the 500 and the 600 is the disk. The pressure plate is the same. I honestly believe the 600 was overkill for my car. ( lesson learned) That may very well have had something to do with me twisting the input shaft. I'm telling you, that 600 grabs like a mofo. Well anyway, my new disk in on its way. It was a special order straight from Exedy. I also ordered their billet flywheel to go along with it.

cool, i bought a spec billet flywheel and 3+ clutch... i hope it doesn't break an input shaft... i really hope it doesn't have to be shimmed... lol...

 

[Blacksmoke]

How did you twist your input shaft?

 

[KDT]

How did you twist your input shaft?

I wish I knew for sure...lol My stock clutch started slipping a little over the summer. Mainly in third gear at wide open throttle. It progressively got worse until I replaced it in late August. I went through the standard 500 mile break-in on the new clutch. The very first time I ran it through the gears, I did a quick shift to third to see how it would grab. The clutch grabbed hard and the car reared up. It never did that with the stock clutch. From then on it would grind going into third if I shifted fast. If I had to guess, I would say that's when it happened.

 

[dysan]

Let me know what you think of the trans rebuild from Liberty. I'm toying with the idea of getting my 3650 rebuilt this winter if I have the $$$.

 

[1BADHRSE]

I was having the same problems before I killed the transmission the builder suggested I do this also! Here is the "HOW TO" he directed me too....
I am doing this for sure to make sure, I just had my tr3650 built and I don't need to chance it...

http://ramclutches.com/Instructions/RAM Hyd Setup.htm

Shows you have to use feeler gauges and math to see what size spacer or shim you need...

 

[KDT]

After a long wait, I finally got my trans back from Liberty. I got it back in the car Thursday night and was able to put a few break in miles on it as well as the new Exedy Mach 500 clutch. Right now I couldn't be happier with it. The trans shifts 100% better than it did from the factory. It is much smoother and goes into all the gears with very little effort. The Mach 500 clutch feels pretty much like the stock one. There is only a slight increase in pedal effort. The engagement is very similar to the stock clutch. It is a little more forgiving than than the Mach 600 which I had previously. The car seems to rev a little quicker with the lightweight flywheel but it has been a while since I drove it so I might be wrong there. The Exedy disk and pressure plate is heavier than the stock one so the lightweight flywheel just offsets that some. The entire assembly is only about 3 lbs lighter than stock when it's all said and done. To sum it up, so far so good. I will post again once I get everything broken in and really let it rip. Oh yea, the last pic is a souvenir I requested back from Liberty. It makes a good conversation piece / paper wight...

 

[Ricosbullitt]

Some great info. Glad it worked out for you. I have had the dead brake and clutch pedal thing happen to me recently but never noticed any leaks....how would the brake and clutch pedal be related?

 

[KDT]

Some great info. Glad it worked out for you. I have had the dead brake and clutch pedal thing happen to me recently but never noticed any leaks....how would the brake and clutch pedal be related?

I would guess there might be something wrong with the master cylinder. That's the only thing the brakes and the slave have in common.

 

[Rick Simons]

Some great info. Glad it worked out for you. I have had the dead brake and clutch pedal thing happen to me recently but never noticed any leaks....how would the brake and clutch pedal be related?

Sorry to butt in, I've been researching the shim-the-slave-cylinder thing as I'm getting ready to install a Mach 350 setup in my car. The clutch and brake share the same fluid supply, so if (when) the fluid gets hot it can affect both systems. I've fitted a motorcycle fluid reservoir for the clutch for my car to alleviate this condition.