Tilton 7.25 OT-II Clutches (98-725R) User Manual

Page 2

CLUTCH DISC INSTALLATION

When installing the pressure and floater plates, be sure to align the painted alignment
marks found on each plate and one clutch leg. This is how the clutch was balanced at the
factory and will also make sure the plates are always installed in the same direction.

Install the plates and discs in to the clutch in the following manner;

SINGLE DISC CLUTCH ASSEMBLY

Contains “V” or “W” in the part number.

1. Install pressure plate with raised ring against diaphragm.
2. Install disc #1 (V or W hub) with TE logo on rivet heads towards the flywheel.

DUAL DISC CLUTCH ASSEMBLY

Contains “VV” or “VW” in the part number.

1. Install pressure plate with raised ring against diaphragm.
2. Install disc #1 (V hub) with TE logo on rivet heads towards the flywheel.
3. Install floater plate.
4. Install disc #2 (V or W hub) with TE logo on rivet heads towards the flywheel.

CLUTCH ASSEMBLY INSTALLATION

Now that the clutch is assembled with discs, install it onto the engine as follows:

1. Slide clutch over the mounting bolts and make sure the heads of the bolts are secure

against flywheel lip. Start aircraft-type washers and nuts onto each bolt by hand.

2. Align discs with an alignment tool or a spare input shaft.
3. Tighten the six bolts in a criss-cross pattern, half-of-a-turn at a time until bottomed.

Torque the nuts to 18 lb-ft using thread locking compound.

4. The tips of the spring fingers should taper slightly towards the transmission. The

spring must not be inverted toward clutch.

5. Install the bellhousing and transmission. Do not let the clutch support the weight of

the transmission while installing.

Note:

Use only aircraft grade hardware (AN or NAS) when installing this

clutch. Tilton offers a wide range of clutch-to-flywheel bolt kits.
Visit www.tiltonracing.com for further information.

PEDAL STOP SET-UP

This clutch must be used with a positive stop on the clutch pedal to prevent over-strok-
ing. Below is an easy means of setting the stop once the drivetrain is in place:

1. Support the rear of the car on jack stands.
2. With the engine off and the car in gear, slowly depress the clutch pedal until the drive

wheels just barely break free.

3. Give the pedal an additional .25" of travel (measured at the foot pad) and lock the

pedal stop in place. This will allow the clutch to cleanly release itself without damage.

4. The theoretical maximum master cylinder stroke with the recommended master

cylinder size is .730" (18.5 mm) assuming .040" cut-off port travel.

MAINTENANCE

Discs: Clutch discs start new at .283" thick. Discs should be
replaced when total pack wears .030". This means the individual
disc thickness should not be less than:

• Single disc = .253" • Two disc = .268"

The friction material used on these discs is extremely wear resis-
tant. It will typically wear quickly for the first .002" of disc thickness,
and then wear dramatically slower after that.

Pressure Plate and Floaters: Check the plates periodically for
warpage. This warping is caused by heat put into the clutch
during engagement. Check warping with a straightedge and
feeler gauge. Maximum allowable warpage is .008" in any plate.
Pressure Plates can be resurfaced to a minimum thickness of
.525". Floaters should never be resurfaced. Be sure to align the
balance marks when reinstalling the plates. After installing the
plates in the cover, rotate them until they contact the thrust
buttons on one side, and use a .006” feeler gage between the
thrust buttons and the plates. This is the minimum clearance
for proper clutch release.

Diaphragm Springs: The spring should be replaced periodi-
cally or if the clutch has been over-stroked. The spring in this
clutch can only be replaced by an authorized Tilton clutch
rebuild center.

SERVICE / WARRANTY INFORMATION

If your clutch requires service, please follow
these procedures:

1. Contact Tilton at (805-688-2353) and describe the problem

or the service that is required.

2. If the clutch needs to be sent in, a Returned Material Autho-

rization (RMA) number is required and will be provided by a
Tilton representative.

3. Write the RMA number on the outside of the package and

keep a record of this number.

4. Ship the clutch by UPS or Fed EX only.

Do not return the clutch without an RMA #

Tilton Engineering, Inc. 25 Easy Street • PO Box 1787 • Buellton, CA 93427 • www.tiltonracing.com

Single

Double

EEL

TCH