Lt4-396

What you describe is exactly the problem I had and with the thinner plate it's back to 100%.

Edd1964

would extending the slave cyl rod help extent the throw

9T3VETTE

This is interesting I've never read this before. Wonder if this is why mine intermittently has trouble going into first and second sometimes..usually pumping the clutch and trying again works. Also has a slight grind under WOT going into fourth

mtwoolford

with LT4-396

I removed and set up my whole clutch m/c, spacers, rod, pedal and supporting assembly on a bench to discover what exactly happens; yes, a thinner spacer does increase the effective travel of the clutch m/c piston;

I reinstalled everything and with the transmission out but with the new clutch installed and the clutch disc held in place with the clutch plate alignment tool I measured the actual travel of the throwout bearing pulling out (my LT has a pull, not the more common push style clutch) ; using the measurements supplied to me by ZFdoc, I found that a spacer approximately one half the thickness of the original piece gave me the results closest to the measurements supplied by ZFdoc.

Needless to say I am very happy with the results, but the whole thing was a major PITA; it just reinforces my belief that nothing should be assumed and that everything should be checked; especially before reinstalling a clutch, trans, c-beam....well you get the picture.

Edd1964

I am finding that out. I must agree,
I am going to remove everything this weekend just to give it all a good look see and re-do it again and see where that will end up.
I did not remove anything from the 95 engine ie bell housing clutch etc... so i figured it was undisturbed and good to go. WRONG we had such a hard time getting the trans back in that now i am wondering if we screwed something up during the install.

Edd1964

well I found the problem. The release bearing fork was bent where the slave cyl connects as compared to the other one I have. I do not know if the 95 forks are that way factory but I am going to use the bell housing from the 92 that is from the trans that is in the car. I am changing the clutch out also since I am in there.

Edd1964

mtwoolford

well that fork bent for a reason (sure age and being operated a zillion times could account for it). check that your fork mounting stud hasn't backed out, and by backing out, I mean unscrewing itself and moving forward, toward the engine

Edd1964

I am replacing the entire bell housing with the other one I have

Red 91

Make sure the inside dia. of the throwout bearing matches the outside dia. of the input shaft.

Christi@n

It is hard to say from that pic, but fork seems not to be bent, that instead seems to be its shape

Edd1964

well success, installed the 92 bell housing with a new clutch,(old one was in great shape) but since it was apart I figured what the hey. trans slid back into place like a glove and everything seems to be working as it should. Maybe the forks between 92 and 95 are different, and the 95 was the one I used the first time. this time it was the original one from the 92. I want to Thank everyone for all of the advice and guidance it led me to the culprit.

mtwoolford

Hey, its just nice to hear back when someone actually solves a problem

Christi@n

Well done

9T3VETTE

Thanks. I'm using the factory spacer between the master and firewall along with an OEM style master and slave remand by powertorque. I'd think all the dimensions would be the same but like you said can't make any assumptions.

To the OP, glad you got it figured out

jmgtp

This talk of a thinner spacer caught my interest. I've had hydraulic issues in the past. I got that sorted and the air out but I've always felt that the shifter should slide into 1st/R with less effort when stopped. I never get a crunch or a lurch but in the back of my mind I wonder if I am getting full disengagement. Is there any way to test in vehicle? What are the risks of a smaller spacer resulting in too much TOB travel? The spacer looks simple enough to be fabricated in a home shop.

jmgtp

Found spacers are cheap and order one. I can mill a tiny bit off at a time and trial/error to see if shifts improve. I guess another risk could be that if milled too thin it seems some constant pressure could be applied to the TOB, speeding its demise.

Will be a few weeks till I try it out.

Lt4-396

It really depends where the clutch is grabbing. If it's right off the floor then it needs a much thinner spacer. If it's grabbing an inch off the floor then you will still benefit from a thinner spacer.
If you break the clutch throw into 3 pieces the first 33% off the floor should do nothing the clutch should grab between 33%-66% then the last third does nothing again.
There is a post about full master cylinder throw and most cars are only utilizing 60% of it.
I started with milling .125 at first then .020 at a time and ended up with about .205 +/- .005 off the original thickness spacer.

Depending on the clutch you may also need a thicker/thinner shim. Some clutches are thicker then OE clutches

jmgtp

Interesting breakdown. My clutch, as I remember it, has always been a high grabber. So it sounds like I may in fact need a thicker spacer based on your logic above. I guess what I can do is cut a .25" section if the extra spacer rather than mill it. This gives me the option to run the original spaced + .25" section or run the replacement spacer that is .25" smaller. Gives me options to try on both ends to see what works best. Should be an interesting experiment.

9T3VETTE

^ I'm interested. Bummer that mine is in storage but def something I'm going to mess around with in the spring. Let's u know what you find out jmgtp