Well its like this. I got the Ram clutch and someone I know said I didnt have to have the adjustable master cylinder for it to work right. So I left it at that. When I put the clutch in, I didnt use the shims that were given, out of ignorance. It almost disengaged, but just didnt release far enough. Called Ram and figured out I needed the shims and they said I need an adj. master as well. So I pull the trans and redo the clutch with the shims. Without putting an adj. master I tried to drive it and see how things were. This time it wouldnt disengage at all! None. After adding shims and taking the pressure plate further away from the flywheel how can this be? This weekend I am going to take it out a third time and hopefully everything is ok. Also I did put in an updated slave when I did this. So that isnt an issue. What do you guys think? I am getting really frustrated. Why cant they just make these damn clutches that dont need shims and adjustment.

Thanks

Brandon

 

Ideas?

 

Brandon, I dont't know exactly what your problem is but when I installed my ram clutch I used the shim that goes between the slave and the transmission, did the drill mod, and installed an adjustable master cylinder and I no problems at all.

 

Did you just use one set of shims or 2? The tech at Ram actually said I probably need two. WTF. Why cant they just make this thing a straight up install. Did you have an issue getting the U studs out of the firewall that hold the master cylinder? The one on the left(while you are in the car)moves freely, the one on the right wont budge. Oh well, its about par for the course.

Brandon

 

I only used 1 shim. Yes changing the clutch master cylinder was a major pita. You have to just keep messing with it and eventually it will come out. It is another pita getting the u studs back in. I am glad I am done with that mod, hopefully will never have to mess with it again.

John

 

you need to use as many shims as it takes to get the ring height to the proper level. in most cases its 3 shims (from the factory)... you need to check this with a the depth checking part of a micrometer through the little hole in the PP.

JR

 

i just got my ram clutch in and there are no shims that came with this set. Just pressure plate, clutch disk and install tool. That's it! I was also told that i didn't need the shims if I had an adjustable master. What gives????????

 

Which RAM clutch???

 

Powergrip "Stage 3"

 

I have a stage 4 with no shims and used a new stock master/slave.Perfect pedal and feel.

 

I bought a powergrip stage II and love it. They told me that when I resurfaced my flywheel to watch the amount. If it was more than .001 then I would need shims. It ended up being .024. I just bought a new flywheel and put it in with a new slave, no drill mod, no adjustable master and it was all good. No problems from this point.

 

When I installed my Ram Powergrip, (Level 3), I didn't use a shim. They didn't supply, or tell you to use one. It had a setup distance of 0.155" from the collapsed slave. With the stock master and new GM slave I couldn't get complete release. I installed a McLeod master, (13/16" bore), which pushes more fluid and had good release. So I couldn't make it work either. Call Thunder Racing, they put them in. They don't always work without a different master cylinder. This stuff about 0.020" or something when resurfacing a flywheel is rediculous when you consider the specs of the slave. All you do with a shim behind the slave is move it closer to the flywheel, moving it farther into its bore. This actually because of slop seems to give a little more release. You dont actually push the slave 0.050" farther if you put a 0.050" shim in at all. The slave only moves as far as the amount of fluid being pushed into it by the master. Bigger master (McLeod), more fluid, equals more slave travel. Putting shims in and limiting flywheel resurfacing is all to push the GM slave cylinder farther into its bore so it travels better and doesn't malfuntion with these aftermarket clutches that are farther away from it than the stock pressure plate. Measure you setup distance before you put the trans in. Shim to achieve 0.125" distance from the pressure plate fingers to the collapsed slave. This will allow your slave to have the minimum travel out of it's bore. It's what all these clutch manufacturers are doing to try to actuate their pressure plates with the stock slave. Again this minimizes the slop in the system and isn't a direct improvement on release, however it is a good thing to shim to 0.125". If this this doesn't work and you have bled all of the air out of the system you will need a larger bore master. The only thing an "adjustable" stock GM master will give you is the ability to lengthen or shorten the rod. If your stock master pushes your peddle against the switch like many do, you can't get more travel on the rod by lengthening it, and it won't give more release. You can only preload it, and if you preload too much will not let the pressure release port in the master open. You can shorten the rod and get less release. You want a larger bore master like the McLeod.

 

This is a really good post. There have been more posts about release problems then I can shake a stick at and suggesting to measure your distance from the compressed slave/throw out to the pressure plate fingers prior to removing the stock setup and after has not been mentioned to my recollection. Keeping the slave piston as much in it's bore is a good idea which makes shimming the slave to make up for different height pressure plates and resurfaced flywheels make the most sense. Pushing more fluid through the system only pushes the slave further than it was designed to go and, of course, lengthening and shortening the rod has no effect unless the positive stop is the clutch inhibit switch in which case shortening the rod to bring the pedal up would add a bit more throw.

So the procedure would be something like:

- Crack the bleeder and push the throw out bearing back to ensure the slave piston is all the way back in it's bore. This might be a PITA and I can't think of a really good way to accomplish this.

- While compressing the throw out spring all the way, measure the distance from the pressure plate fingers to the throw out bearing surface. Compressing and measuring at the same time may also prove to be difficult.

- Do the same procedure after installing the new clutch assembly and shim the slave to achieve the same distance or get it down to ~.125". I have not seen pics of the slave shims but I would assume they have slots cut in them so as to be able to insert them without having to actually remove the slave off the input shaft.

ATL, maybe you could post suggestions or alterations for the first two steps.

 

Well I agree that I haven't seen anything posted about this subject. This is all basic setup for a hydraulic throwout bearing, (slave). It may have been discussed, and I would assume some are familiar with this measurement. One point I was trying to make was the real reason you shim a slave and what it does. I actually have all the dimensions of a stock GM '288' slave and will post them. The trans will be removed to do this and you want the dimensions of the new clutch that your installing. It is hard to hold the piston in as you point out. I removed the spring by pulling off the plastic collar and installed it without the spring to make the measurement. You should be able to push an installed slave into its bore because there is a pressure relief in the master that will let you push the fluid back. You would pull this off anyway when changing the bearing with and old slave. Just reinstall the spring after making the measurement. When installing a new slave just use the old slave and make the measurement. Remember this is the distance from the collapsed bearing face to the mounting face of the trans. The other dimension is the distance from the pressure plate fingers, (the ones that are farthest out toward the rear of the car), to the mounting face of the bellhousing. Take the pressure plate finger to bellhousing measurement and subtract the collapsed slave to trans mounting face measurement. This is your setup distance. Shim behind the slave to achieve 0.125" difference of the two measurements. You have to leave this because as the disc wears the pressure plate fingers will actually move toward the rear of the car. You don't want to have the bearing pushing against them when the wear occurs. I am also being conservative on this number. Some may say 0.100" is enough. I would consult the manufacturer on this number if you want to go below 0.125". The shims I received from spec have a hole in the middle and you do have to pull the slave off the input shaft to install them. I also fabricated my own shim.

 

That makes sense. I guess I wasn't thinking 'out of the box' to think how to do it with the tranny (torque tube in Y-Body terms) out. Measuring in from the mating points works.

 

Another issue is whether you purchased the plate separate or in a kit. If you use the off the shelf 402, this finger height is lower than the unit in the kits. We build this plate specific for the proper setup height in LS1 cars.

 

Good info AtlantaRTA...thanks for sharing.

 

Something I want to mention is that the aftermarket clutches do sometimes work with the stock hydraulics. The travel of the stock master and slave seems to be so close to what is needed to completely release these clutches that sometimes it falls short. When the clutches are installed complete disengagement can be the problem that people experience. Shimming the slave to minimize the mechanical slop in the system is what works for some. Of course always make sure the system is bled completely. This isn't as easy as it seems and is much easier if the components are bench bled first. If bleeding and shimming the slave to the proper setup distance fail to completely release the clutch more fluid needs to be pushed into the slave. If using an adjustable GM master you have to be able to lenghten the rod pushing the peddle against your clutch switch. That's the switch at the top of the peddle when it's released. If using a larger bore master such as the McLeod you will push more fluid and therefore have more release.

 

Are you serious!!! How much is it different? And the real question...why the hell would you do that?

I thought I bought mine in a kit (from new era performance) but apparently I didn't cause the clutch barely disengaged when the pedal was on the floor, and yes it was bled, and yes I had a new slave. I had to put the stock clutch back in cause i couldn't drive it like that, and guess what, the stock clutch engages right where it should. I guess I'll have to get a shim now but I need to know what size.
Ram Clutches

 

If you purchased the kit for your car then the lever position should be correct. The problem comes with buying the components separately - the same pressure plate can be used in early GM apps and those have mechanical linkage so adjustment is not an issue.

The kits are built to the lever height spec of the standard LS1 clutch, so as to not need shimming. The only times we have needed to shim are a) if the flywheel has been surfaced too much or b) the hydraulic system is inadequate, not functioning properly, or not bled completely.

If you feel the problem is in the clutch then I will certainly inspect it and correct any problems, should they be present!

Mike