60th Birthday - Winter Work - '07 & '08

 

 
 

 

  

Critical Measurements

The most critical part of this installation is taking some key measurements at both the pressure plate side and at the throw out bearing side. In order to do this properly you need some sort of measured platform to use as your "base".  So, remember those bolts from the preceding page.......I ended up only needing to use two of the threaded rods.

Bolts locked to engine backing plate & Nyloc nuts to use as a platform base
It MUST measure EXACTLY 4" from either the face of the engine block (if you don't
have an engine backing plate) or from the face of the backing plate (like I have here)
 to the top of your platform base. In hindsight, I would have screwed the nylocs on upside
down to give me a little larger base to rest the straightedge on.
I had a nice thick straight piece of molding that I drilled two holes in and slipped it over the
bolts. You can use anything as long as it's straight and solid.
Here you can see the straightedge resting exactly 4" off of the backplate.
Use a carpenter square to measure from the straightedge to the PP Fingers. Next is to measure
that little yellow line.
Use your caliper to measure the depth from the end on the square to the straightedge. Write that
number down and take a few more measurements to double check. This is your "A" measurement.
In hindsight, I wish I had used my cheapo old plastic dial caliper. The digital ones are too
sensitive and record every little variance in a big digital read out. It drove me nuts!

Now it's time to install the t/o bearing on the tranny input shaft. But first.......some testing. I did not want to go through a leaky bearing again.......be it the bearing itself or a lousy hose tightening job by me. So I made up a test "rig"

A block of wood with a hole large enough to let the bearing pop out about 1/8" and another
flat piece for the other side.

Roll it all next to the car, hook up the hose to the M/C, clamp the wood to the bearing, fill &
bleed the assembly and pump the clutch. You can't over-extend the bearing and you'll see if
there's any leaks at the bearing or at the hose connections. It takes a little time and uses up some brake fluid but it's a lot easier and quicker then having to pull the tranny due to a leak.

Time to install the Throw Out Bearing......first there's these shims......start with 6 of them
Next....lube the "O" ring in the t/o bearing with some brake fluid and slide it on the tranny nose.
Now we do the same Measurements on the Throw Out Bearing side
And measure the distance.........write this number down as your "B" measurement

OK.....time to step back and understand what these measurements mean. Let's start with measurements "A". If you go back to setting the measuring distance at 4" we used the caliper to determine the distance from our straight edge to the pressure plate fingers and called it measurement "A". Let's assume, for simplicity sake that the distance was 0.50". Take that number and subtract it from 4" so 4.00 - 0.50 = 3.50". Therefore 3.50" is the final "A" measurement . The 1st goal here is to get the A & B measurements to be the same.....or as close as we can get them. In other words we want "B" to measure 3.50". Add or remove shims as required to get the measurements equal or close to it. When you have them "equal" it means that, if you were to install the tranny, the t/o bearing would be touching the face of the pressure plate. We don't want them touching so read the t/o bearing instructions to see what spacing is required. My bearing wanted a minimum of 0.125" and a maximum of 0.185" of separation between the t/o bearing and the pressure plate fingers. So when the tranny is installed, the t/o bearing is a minimum of 0.125" and a maximum of 0.185" from the face of the pressure plate. I had to remove a shim or two to obtain this spacing. I think my final "B" measurement ended up being 3.64"....... 3.50" + 0.140" = 3.64". The 0.140" fell right between the minimum and maximum required.

All that's left to do now is install the bushing on the tranny nose and the bearing's anti-spin stud.

Bushing (yellow arrow) takes some "persuasion"
to slide on the nose. Orange arrow points to
the bearing's anti-spin stud
A close up of the anti-spin stud

Now we're ready to attach the tranny to the engine.