Diagnosis And Testing; Low Lubricant Level; Hard Shifting; Transmission Noise - Jeep cherokee 2000 Service Manual

21 - 44 NV3550 MANUAL TRANSMISSION
GENERAL INFORMATION (Continued)
Fig. 3 Drain and Fill Plug Locations
1 – DRAIN PLUG
2 – FILL PLUG

DIAGNOSIS AND TESTING

LOW LUBRICANT LEVEL

A low transmission lubricant level is generally the
result of a leak, inadequate lubricant fill, or an incor-
rect lubricant level check.
Leaks can occur at the mating surfaces of the
housings, or from the front/rear seals. A suspected
leak could also be the result of an overfill condition.
Leaks at component mating surfaces will probably
be the result of inadequate sealer, gaps in the sealer,
incorrect bolt tightening, or use of a non–recom-
mended sealer.
A leak at the front of the transmission will be from
either a loose or damaged, front bearing retainer or
retainer seal. Lubricant may also drip from the
transmission clutch housing after extended opera-
tion. If the leak is severe, it will contaminate the
clutch disc causing slip, grab and chatter.
Transmissions filled from air or electrically pow-
ered lubricant containers can be under filled. Always
check the lubricant level after filling to avoid an
under fill condition.
A correct lubricant level check can only be made
when the vehicle is level; use a drive–on hoist to
ensure this. Also allow the lubricant to settle for a
minute or so before checking. These recommenda-
tions will ensure an accurate check and avoid an
under-or-overfill condition.

HARD SHIFTING

Hard shifting is usually caused by a low lubricant
level, improper or contaminated lubricants, transmis-
sion component damage, clutch linkage malfunction,
or by a damaged clutch pressure plate or disc.
Substantial lubricant leaks can result in gear, shift
component, synchro and bearing damage. If a leak
goes undetected for an extended period, the first indi-
cations of a problem are usually hard shifting and
noise.
Incorrect or contaminated lubricants can also con-
tribute to hard shifting. The consequence of using
non–recommended lubricants is noise, excessive
wear, internal bind and hard shifting.
Improper clutch release is a frequent cause of hard
shifting. Incorrect adjustment or a worn, damaged
pressure plate or disc can cause incorrect release. If
the clutch problem is advanced, gear clash during
shifts can result.
Worn or damaged synchro rings can cause gear
clash when shifting into any forward gear. In some
new or rebuilt transmissions, new synchro rings may
tend to stick slightly causing stiff and/or noisy shifts.
In most cases, this condition will decline as the rings
wear in.

TRANSMISSION NOISE

Most manual transmissions make some noise dur-
ing normal operation. Rotating gears can generate a
mild whine that may only be audible at extreme
speeds.
Severe, obviously audible transmission noise is
generally the result of a lubricant problem. Insuffi-
cient, improper, or contaminated lubricant can pro-
mote rapid wear of gears, synchros, shift rails, forks
and bearings. The overheating caused by a lubricant
problem, can also lead to gear breakage.

REMOVAL AND INSTALLATION

TRANSMISSION

REMOVAL
(1) Shift transmission into first or third gear.
(2) Remove the floor console and shift boot as nec-
essary to access the bottom of the shift lever at the
shift tower attachment.
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