Hydraulic Throw Out Bearing install

Bob Streu

SDC #67658 ( Dec 2012)

T-56 6 speed

....ordered the OEM (Throw Out Bearing) setup and off we go.

The hydraulics in the F-bodies use a 2" distance from the clutch pivot to the MC plunger mount so I used that number. The MC plunger travel distance is 15/16" and building that into the Avanti clutch pedal gives a little over 5:1 ratio and a travel of 5" at the pedal.

I mocked the pedal to travel from 6" off the floor (total travel of the pedal originally is about 6 3/4" from the floor) to 1" off the floor. That should give me room for carpet and insulation and a stop for the pedal so I don't over extend the slave with to much travel from the MC.

I then mocked up the clutch rod to give an angle that would clear the Brake MC and let the brake and clutch pedals swing clear of each other. I ended up with this configuration that keeps the clutch plunger travel almost in a straight line over 15/16" travel and clears the brake MC.

That's the minimum clearance, I plan to build a shoulder bolt for the clutch rod attachment and that will give me about 3/8" of clearance between the pedals. The washers will be replaced with a bushing welded to the pedal. The washer stack is 3/4" so that will be the bushing length.

Clearance below the Brake Booster.

And without the booster.

My plan is to build a bracket to support the clutch MC that fits under the brake booster mount and also bolts to the inner fender for more support.

That will require more time than I have today so consider that a preview of coming attractions.

One last data point, the 383 stroker needs a special flywheel to connect the two piece rear seal engine to the LT1 T-56. A Centerforce 700173 is on the way.

One of the reasons for posting this early is to solicit opinions on what's been done and on further mods. After all, T-56 installs into Avanti's don't seem to be very prevalent on the forum nor web.



During our discussions I was aware of the differences but needed advice on what was required on size and cylinder displacement as well as availability so your input was valuable. Interestingly, during my investigations, I found that the newer OEM units came with the braided line standard so I made sure that was what I purchased. Another advantage is they come assembled with fluid added so there will be no bleeding issues.

The T-56 is a large tranny but it is setting on the pole barn floor close to a 700R4 that came out of my 83 Avanti. It's about as wide but slightly shorter so it should not interfere with the X-member. In any case, it'll fit I have a torc----- OOPS!!! A gallon of resin and a large supply of glass cloth and mat.

While there is little info on these swaps into Studebakers, there is a tremendous amount of data on swapping them into older GM bodies so a lot of fitment issues have some clues available. The hydraulic system really cleans up the clutch setup in the Avanti's. Even if I had kept the 4-speed I would have gone with the hydraulics.