It does not have any pressure against the clutch, but it will only retract as far as the clutch fingers push it. So it may or may not spin when released.

 

Its the same as the pistons in your brake calipers, there is a gap when you put the pads in, then after the first time you push the pedal down the gap is gone, but as long as your foot is off the pedal there is no presure. Then as the pads wear the pistons move out and stay out. Obviously our clutches don't have to compensate as much for wear like the brakes but you get the idea. In most cases as clutches wear the fingers stick out more so that would close the gap on our setups, which is why there is a minimum clearance given.

 

I agree. This is why I went from a little clearance slightly negative.

 

I will have my measuring done very soon. Too many people have all the answers already it seems though. Personally I know either my crank is a different length sticking out of the back of my block, or something was machined incorrectly at quartermaster be it the flywheel or the hrb or something. All other possibilities have been eliminated at this point. I have another 2.0 stock longblock sitting at my house with 20k miles on it... I am going to bolt my transmission with the HRB in the same installed position to the stock block and check my clearance. I'll have a better idea of whats going on soon, and will have a FOR SURE answer for you guys in the near future! I will make a few calls tomorrow and check on if the HRB is supposed to be touching the fingers of the clutch, seems strange, how can you keep an eye on clearance if the bearing rides on the fingers at all times?

 

Also who really wants to buy a new clutch and then have to machine to HRB to spec???

 

Your not suppose to have to keep an eye on it, they give that minimum clearance so that it should be worn out before you run out of clearance. How ever thinking about it, your clearance will vary depending on the position of any crank in the block. For example, lets say you have a thrust clearance of .004, the clearance from the clutch to the HRB will change depending on where the crank is in that .004 when you measured it. If you want to measure it as it wears I guess you could try to get something in there to push the HRB back in to the assembly but I dont think it would be worth the risk, if you put a pry bar up there to push it in you could risk damaging the HRB. If you are worried about it you can always check your thrust at the front of the motor with a dial indicator. As long as your crank can move freely you will be fine. If it wont move, then you will be destroying your thrust bearings. Please note your crank should only move a little, depending on the builder .003-.010" so this must be checked with a dial indicator.

 

You measure your clearance with a set of dial calipers and a straight edge. Trans off the engine.

 

Yes but if its already in and being used you cannot measure it that way.

 

Have you taken any measurements Straightline?

 

Isnt this problem also solved by using a clutch stop? By preventing over extension.

 

no

 

Not yet, I am going to have some soon, I know I keep saying that, but I will. I have a 20k mile shortblock with stock crank I'm measuring tonight w/o flywheel, with flywheel, then measuring the installed height off the black of the block with the clutch. going to see what changes through my testing on a few different setups because something does obviously.

 

I had some questions about your setup.

Did you use the plate between the engine and trans? I've seen a few builds where people don't reuse that plate.

Did QM tell you how much they removed for proper bearing clearance.

I'll take some measurements for you guys. I should have something by tomorrow night.

 

Yes, I used the plate. Quarter Master told me that they were taking off right at 200 thousandths. It would have been even more out of spec without the plate.

 

So, assuming the distance between the TOB and pressure plate is the issue, would spacing the transmission out from the engine be a viable idea?