Tilton 52XX User Manual
INSTALLATION INSTRUCTIONS
60-52XX Hydraulic Release Bearing
Description
Tilton’s 60-52XX Hydraulic Release Bearing (also known as a concentric slave cylinder) is designed to
be mounted inside bellhousing. This hydraulic bearing assembly uses a radius-faced bearing with a
44mm contact diameter that is intended to work with Tilton 7.25" racing clutches.
If you are using something other than a Tilton 7.25" clutch you must verify that your clutch is
designed for a 44mm bearing.
The hydraulic release bearing assembly is self-adjusting in that the bearing stays close to the clutch
spring at all times. Although the spring changes position with clutch wear, there is no extra return
spring that pulls the piston back all the way to the bottomed position. In this respect, the piston in
the hydraulic bearing assembly works like the piston in a disc brake caliper, returning only as far as
forced. For this reason, with a Tilton hydraulic release bearing the feel of the clutch does not change
with clutch wear allowing the driver to make more consistent shifts.
prior to installation
1. Both ports of the hydraulic release bearing are threaded 3/8-24 UNF x .28" deep with a 37º
tapered seat and are suitable for use with standard AN-3 or JIC 37º ttings. Alternatively, the top
of the port is machined at for use with a crush washer (banjo tting installations). Two AN-3 to
AN-3 union ttings are supplied with the slave cylinder. If you choose to use banjo bolts instead,
be sure that the bolt does not stick out past the bottom crush washer by more than .28".
2. Hydraulic hose is not included with this hydraulic release bearing. It is up to you to source
high quality hose and a bleed tting assembly. We recommend the use of PTFE lined stainless
braided hose for the entire length of both the feed and bleed lines.
3. For most standard clutch pedal ratios, this hydraulic release bearing and a Tilton 7.25" clutch will
work best with a 3/4" bore master cylinder.
installation
Bearing clearance and mounting
1. Some applications may require you to cut the pilot tube o the gearbox input shaft bearing
retainer. You may need to remove the bearing retainer from the gearbox to do this.
2. As received in the box, the bearing piston may not be fully retracted. You will need to compress
it before taking any measurements. The small lip on the outside diameter of the piston is
intended to bottom against the orange wiper seal.
3. Position the bearing assembly on the surface you wish to mount it so one port points directly
up. This will be the port to which you attach the bleed line. Both ports are identical, so either
one can be placed in the upward position. The other port will be attached to the supply line.
Its orientation is not critical. Position the lines so they are clear of the clutch and ywheel.
4. Prepare the mounting surface to which the assembly will be attached. Four bolts (1/4" or 6 mm)
hold the assembly in place. Accurate positioning should be done with a register on the I.D.
or the O.D. of the four legs. This register should be on center with the input shaft within
.010" (.25 mm).
5. Check the bearing clearance. A clutch assembly with worn friction discs will not provide
accurate results, so make sure new friction discs are used when taking measurements. The
bearing clearance must be in the range of .170"-.230" (see Diagram 1). If the clearance is less
than this range, there will not be enough room to allow for the full wear range of the clutch
since clearance reduces with clutch wear.
6. If the assembly is too short or too long, Tilton has pistons available in a range of lengths (see
drawing). Also, note that the plastic shim under the bearing (.050" thick) may be removed for
additional clearance if needed). If the shortest piston and removal of the shim still makes the
assembly too long, the four legs of the hydraulic base can be accurately trimmed on a lathe.
Block all por ts to prevent chip entry if any machining is to be performed.
98 -1135
Diagram 1
.170"- .230"
Bearing Clearance
(New Clutch)
Bearing Fulcrum
Spring Contact Point
Hydraulic lines and ttings
Install the two supplied union ttings and tighten. These ttings are made to seal on the tapered
section and not the threads. Do not use pipe tape or other sealants.
Install the (customer-supplied) hydraulic lines and bleed tting assembly, routing both of the lines
clear of the exhaust system, oil lines and other heat sources.
Master cylinDer priMing
1. Fill the master cylinder with brake uid. Use a DOT 3, DOT 4 or other non-silicone based uid.
Avoid DOT 5 (silicone based) uids since they are not compatible with the seals.
2. Open the bleed tting (if equipped) at the master cylinder while the line port is closed.
3. Gently depress the clutch pedal, close the bleed screw and release the clutch pedal.
4. Repeat Steps 1 and 2 until uid free of air bubbles emerges.
Do not stroke a Tilton master cylinder more than 1".
HyDraulic release Bearing BleeDing
1. Fill the master cylinder reservoir with DOT 3 or DOT 4 brake uid.
2. Apply approximately 3 lbs of force on the clutch pedal. You want enough force to hold the
bearing out against the clutch diaphragm spring, but not enough to actually move the spring.
3. Open the bleed screw that is attached to the bleed line on the hydraulic release bearing.
4. Completely stroke the pedal.
5. Close the bleed screw.
6. Let the pedal return to its relaxed position and wait a few seconds.
7. Repeat Steps 2 through 6 while keeping an eye on the uid level until all air is removed
from the system.
Note: You do not want to stroke the clutch during the bleeding process.
All you are trying to do at this point is get all of the air out of the system.
Do not stroke the clutch until the p edal stop is set!
clutcH peDal stop
A positive clutch pedal stop must be used to prevent over-stroking the
hydraulic release bearing piston and the clutch. With a Tilton 7.25" clutch and a
3/4" bore master cylinder, you will need approximately .79" of master cylinder
stroke for proper clutch release. For access reasons, in many cars it is not easy
to determine how far the master cylinder is being stroked. The method listed
below provides a very eective method for adjusting the pedal stop:
1. Lift the drive wheels o the ground and support the car on jack stands.
2. With the engine o, place the gearbox in rst gear and have someone
attempt to rotate the drive wheels.
3. Depress the clutch pedal slowly until the clutch disengages and the drive
wheels can be rotated.
4. Adjust pedal stop to allow another 1/4" of pedal travel. This should provide
clean release of the clutch. Do not stroke the pedal any further than this
point throughout this procedure, otherwise you will over-stroke the clutch.
FIREWALL
Diagram 2
Pedal position where
pedal stop should be set.
Never travel clutch
pedal past this point!
Pedal position where
clutch breaks free.
Adjustable
Pedal stop
1/4" additional travel
(exaggerated for clarity)
Loading...