There are a handful of advantages to Hydraulic Throw Out Bearings (TOB for short) over the traditional Mechanical type, but today we will talk about the Hydraulic TOB pitfall, “The Seals!!”

There is a surefire way to know when your TOB is dead or on it’s way out.  A puddle of brake fluid under the bell housing is as sure as you can get.

The car arrived with an empty TOB reservoir, after filling it to the correct level and operating it a couple times, it did not leak.  Hmmm….   So I was determined to find out WHY!!

I hooked up my micro camera and pointed it right at the bright red McLeod TOB.  No leaks to be seen.


Fired up the engine and saw the seals leaking only when the engine was running and the clutch was held down for more than 2 seconds.  Unfortunately, that would not leave a “Big Puddle” but more of a “Dripping Trail” which is not so easy to discover.

The Kit was ordered and transmission was dropped.

The bearing itself was showing signs or heat discoloration.

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It seemed a better time than ever to change out the clutch and pressure plate.

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The seal kit is actually quite simple, just be sure to change the seals in a clean environment and Do Not use Grease on the seals.  Use Brake Fluid or ATF.  Whatever was in there to begin with and what you plan to use in the reservoir, should be the same thing!

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By the way, something I learned about 5 speed TREMEC transmissions.  The manufacturer recommends GM ATF Fluid in the case, but a good source pointed me towards using Mobil motor oil instead.  And I must say, the car runs smooth as ever.

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