Ranger 4WD L4-134 2.2L DSL (1983)
Pilot Bearing: Technical Service Bulletins
Clutch Release Bearing - Noise Diagnosis
NOVEMBER 4, 1982
Article: 82-23-26
NOISE - CLUTCH RELEASE BEARING -
DIAGNOSIS
LIGHT TRUCKS
1983 RANGER
The following outline is designed to provide a step-by-step detailed procedure to properly identify the source of a noise and, in particular, to determine if
the release bearing is a probable cause prior to tearing down the powertrain.
The release bearing is a premium quality, constant run, full-angular contact, self-aligning design that will not necessarily require replacement each time
the clutch is serviced. The bearing can be reused unless roughness, binding or other specific concerns are noted. A careful and thorough vehicle
evaluation should be done prior to concluding that any noise emitted from the clutch/transmission area is related to the release bearing.
The clutch release bearing is in constant contact with the clutch fingers with a minimum of 20 lbs. pre-load. This results in the bearing always rotating.
Any noise being emitted from the release bearing will be persistant while the engine is running in any gear including neutral and when the clutch is either
engaged or disengaged.
Diagnostic Procedure in Determining Release Bearing Noise
^
Start engine and warm-up for approximately 5 minutes in neutral.
^
Eliminate all other possible internal/external noise sources (i.e.. roll-up the windows, shut-off the radio and A/C, etc.)
^
Starting with the clutch pedal fully up (clutch engaged) slowly depress the pedal, stopping at the disengagement point. If the noise disappears at this
point, it is most likely a transmission related concern and is not the release bearing because the transmission input shaft has come to a stop while the
release bearing is continuing to rotate at engine speed.
^
If the noise does not cease, continue depressing the pedal to the floor until the clutch is fully disengaged. A bearing related noise will continue
constantly through the clutch disengagement cycle and will most likely increase in intensity upon reaching the full pedal stroke.
^
There is a possibility that noise will not be noted until the reserve point of the clutch cycle is reached during disengagement. If this condition exists,
the noise is pilot bearing related. The pilot bearing is functional only when the transmission input shaft is not turning while the clutch pressure
plate/engine flywheel are still rotating. This situation occurs only at the point of reserve.
^
An exception to these results is a high pitched squeal or chirp with the pedal fully up that disappears when the clutch pedal is lightly depressed
(approximately 1/4-1/2"). This is a release bearing/clutch finger noise problem. However, the bearing is not necessarily the causal factor as will be
explained in detail below.
Typical Clutch Release Bearing Noise Diagnosis:
^
Constant Grinding or Scraping - This noise is a result of failure to the release ball bearing (e.g. rough raceways, loss of lube, missing ball, etc.)
^
Squeal or Chirp - This noise is due to slippage between the clutch fingers and the bearing face because of a lack of pre-load. A lack of pre-load is
attributable either to the hydraulic actuator slave cylinder spring or a lack of lubrication at the release lever or transmission input shaft bearing
retainer.
^
Squeal/Chirp/Squeak - This noise is the result of a damaged or insufficiently lubricated clutch pilot bearing. Replace, if necessary, per Section 16-01
and 16-02 of the 1983 Ranger Shop Manual.
In summary, the release bearing is suspect only if a noise occurs both with the pedal up and the transmission in neutral and with the pedal down and the
transmission in gear. If the noise disappears in either mode, the transmission or pilot bearing should be considered as the noise source, not the release
bearing.
OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: "INFORMATION ONLY"
