The Ideal Measurement for RAM Hydraulic Bearings

May 31, 2022 | Hydraulic Bearings

Part 2 – Aftermarket Bearings


Last month we discussed the importance of properly setting up the factory internal hydraulic bearing with your new clutch system. The few extra minutes it takes to measure and set up these bearings correctly is just as important with an aftermarket release bearing like our RAM units.

Most aftermarket bearings are built on a principle of ‘gap’ or bearing ‘freeplay’. In comparison, factory slave cylinders are set up based on ‘preload.’ The measurements are just as essential to ensure your clutch system will operate correctly and provide a long service life.

RAM delivers an assortment of shims with each kit to help you. Keep in mind that clutch and transmission packages vary widely in their setup heights. It is not uncommon to need extra shims or a longer anti-rotation stud. These parts can be found in our store when you search for ‘hydraulic accessories‘.

The ideal gap for a RAM hydraulic bearing is .150-.200″. As your clutch wears, the fingers will get taller and this gap will diminish. So you want to have enough to allow for wear over time without the bearing bottoming out on the fingers and causing the clutch to unload or slip. I prefer to target the .200″ number in your setup, especially with a dual-disc clutch.

Some things to watch out for as you do this install:

Once you have completed all of your setup measurements, manually extend the bearing to its full travel, then check the stud length. It would be best to trim the stud so the tip is engaged in the bearing anti-rotation slot but not protruding far enough to hit the clutch cover.

Make sure you leave slack in your hydraulic lines to allow the bearing to move forward and back.

Also, ensure the lines will not contact the clutch fingers or cover. Some installs require a 45-degree fitting to angle the lines back away, especially with three-finger clutches.

When performing the bleed, leave the system closed and pump, pump, pump! Make sure you have an assistant keeping the fluid reservoir full. You will need to pull the pedal back up as you do this with your toe. Expect to get a pedal ‘feel’ about halfway up before continuing to bleed like a conventional set of brakes.

We provide a handy setup instructional guide and a video of an install on a 6-speed transmission to help you understand the process. Once you have completed this the first time, you will have an easy time with any additional installs you may do in your shop or helping a friend with a similar installation.