Project SC300 Road Racer: Part 19 – Achieving Release, Mounting Problems
Measuring HRB Bearing Race to Transmission Face Distance
Then we measured from the HRB to the transmission face as instructed, and realized we had a problem.

It’s really important to use a high-quality straight edge when making these measurements, as you’re dealing with single millimeters (or single thousandths of an inch). But that wasn’t our problem. Our problem was the author and the fact that parts didn’t all come directly from Grannas Racing. That’s right, instead of getting everything from Grannas all at once, we got some things from each vendor and somewhat pieced it all together ourselves. So, blame Erik for getting it wrong. Getting what wrong, exactly?

Grannas’ kits are designed with mega power applications in mind. You know, the kind of 2JZs that make 1000-1500HP. As such, Joel’s Tilton kit uses a quad-plate carbon clutch. A four-plate clutch stacks much higher than a two-plate clutch.

Tilton HRB Threaded Collar Plate Attached to T56 Transmission Over Input Shaft
This little plate is what the HRB assembly screws onto.

The HRB rides up and down the threaded collar so that you can set the “height” (distance) of the HRB from the fingers appropriately. The HRB part number that Grannas recommends has a specific throw, but that throw was intended to be paired with a 4-plate clutch. With a 2-plate clutch, The same HRB’s throw was too short! The threaded collar wasn’t long enough, because it was never intended to be, as Tilton has HRB assemblies of all different lengths and throws. How would we fix this problem?

Well, this little plate happens to simply have the threaded portion pressed into the base. One of the benefits of being next to Road Atlanta is that L2 is also right next to a fabrication and race shop called Hypersport Engineering. Kirt, the owner and fabricator, was able to pull out the threaded portion and make an extension/insert to get us some extra overall length so that our HRB could stay within its rated throw and touch the clutch fingers. Whew.


Tilton 6000 Series Hydraulic Release Bearing Installed on T56 Transmission
Here’s the properly adjusted and installed HRB assembly.

Take note of the little post/stud at the bottom of the HRB assembly. The HRB is just screwed onto the collar, and the bearing race will generally be touching the clutch fingers. So, the whole HRB assembly wants to rotate. The little post/stand/bolt keeps the HRB assembly from rotating. The Tilton kit includes posts of two different lengths, but it doesn’t need to be crazy as it’s not seeing a lot of force/torque. Read the instructions.


Tilton HRB Braided Hoses Wrapped and Protected
Here’s another view of the HRB and transmission.

We’ve added some hose protector over the braided hydraulic lines to prevent any damage from chafing and vibration. Again, attention to detail. You can also see that the HRB has two hydraulic connections. One is the input from the clutch master, and the other is for bleeding. Grannas Racing includes a proper -AN male-male adapter that mates the braided clutch master hose he supplies to the HRB’s hose.

Speaking of the clutch master…

Hydraulic Vacuum Line Attached to Slave Bleeder
A vacuum was used to suck the remaining clutch fluid out of the master through the slave’s bleeder.


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