Chevrolet Silverado / GMC Sierra. Service manual — part 1228

MANUAL TRANSMISSION

MANUAL TRANSMISSION TROUBLE SHOOTING

MANUAL TRANSMISSION/TRANSAXLE TROUBLE SHOOTING

CONDITION & POSSIBLE CAUSE

CORRECTION

Excessive Noise

Loose pump-to-drive assembly screws

Tighten screws

Loose tube on pump assembly

Tighten tube

Valves not functioning properly

Replace valves

Oil Leakage

Loose end plug

Tighten end plug

Bad seal crimp

Remove and re-crimp

seal

NOTE:

This is GENERAL information. This article is not intended to be
specific to any unique situation or individual vehicle configuration.
The purpose of this Trouble Shooting information is to provide a list
of common causes to problem symptoms. For model-specific
Trouble Shooting, refer to SUBJECT, DIAGNOSTIC, or TESTING
articles available in the section(s) you are accessing.

Condition

Possible Cause

Noisy In Forward Gears

Low gear oil level, Loose bell housing bolts,

Worn bearings or gears

Clunk On Deceleration (FWD Only)

Loose engine mounts, Worn inboard CV

joints, Worn differential pinion shaft, Side

gear hub counterbore in case worn oversize

Gear Clash When Shifting Forward Gears

Clutch Out Of Adjustment, Shift linkage

damaged or out of adjustment, Gears or

synchronizers damaged, Low gear oil level

Transmission Noisy When Moving (RWD
Only) Quiet In Neutral With Clutch Engaged

Worn rear outputshaft bearing

Gear Rattle

Worn bearings, Wrong gear oil, Low gear oil,

Worn gears

Steady Ticking At Idle (Increases With
RPM)

Broken tooth on gear

2008 Chevrolet Silverado 1500

GENERAL INFORMATION Trouble Shooting - Basic Procedures

POWERTRAIN

CLUTCH TROUBLE SHOOTING

BASIC CLUTCH TROUBLE SHOOTING CHART

Gear Clash When Shifting Forward Gears

Worn or broken synchronizers

Loud Whine In Reverse

Normal condition

(1)

Noise When Stepping On Clutch

Bad release bearing, Worn pilot bearing

Ticking Or Screeching As Clutch Is Engaged Faulty release bearing, Uneven pressure plate

fingers

Click Or Snap When Clutch Is Engaged

Worn clutch fork, Worn or broken front

bearing retainer

Transmission Shifts Hard

Clutch not releasing, Shift mechanism

binding, Clutch installed backwards

Will Not Shift Into One Gear, Shifts Into All
Others

Bent shift fork, Worn detent balls

Locked Into Gear, Cannot Shift

Clutch adjustment, Worn detent balls

Transmission Jumps Out Of Gear

Pilot bearing worn, Bent shift fork, Worn

gear teeth or face, Excessive gear train end

play, Worn synchronizers, Missing detent ball

spring, Shift mechanism worn or out of

adjustment, Engine or transmission mount

bolts loose or out of adjustment, Transmission

not aligned

Shift Lever Rattle

Worn shift lever or detents, Worn shift forks,

Worn synchronizers sleeve

Shift Lever Hops Under Acceleration

Worn engine or transmission mounts

(1)

Most units use spur cut gears in reverse and are noisy

NOTE:

This is GENERAL information. This article is not intended to be
specific to any unique situation or individual vehicle configuration.
The purpose of this Trouble Shooting information is to provide a list
of common causes to problem symptoms. For model-specific
Trouble Shooting, refer to SUBJECT, DIAGNOSTIC, or TESTING
articles available in the section(s) you are accessing.

CONDITION & POSSIBLE CAUSE

CORRECTION

2008 Chevrolet Silverado 1500

GENERAL INFORMATION Trouble Shooting - Basic Procedures

Chattering or Grabbing

Incorrect clutch adjustment

Adjust clutch

Oil, grease or glaze on facings

Disassemble and clean or

replace

Loose "U" joint flange

See DRIVE AXLES article

Worn input shaft spline

Replace input shaft

Binding pressure plate

Replace pressure plate

Binding release lever

See CLUTCH article

Binding clutch disc hub

Replace clutch disc

Unequal pressure plate contact

Replace worn/misaligned

components

Loose/bent clutch disc

Replace clutch disc

Incorrect transmission alignment

Realign transmission

Worn pressure plate, disc or flywheel

Replace damaged

components

Broken or weak pressure springs

Replace pressure plate

Sticking clutch pedal

Lubricate clutch pedal &

linkage

Incorrect clutch disc facing

Replace clutch disc

Engine loose in chassis

Tighten all mounting bolts

Failure to Release

Oil or grease on clutch facings

Clean or replace clutch

clutch disc

Incorrect release lever or pedal adjustment

See CLUTCH article

Worn or broken clutch facings

Replace clutch disc

Bent clutch disc or pressure plate

Replace damaged

components

Clutch disc hub binding on input shaft

Clean or replace clutch disc

and/or input shaft

Binding pilot bearing

Replace pilot bearing

Sticking release bearing sleeve

Replace release bearing

and/or sleeve

Binding clutch cable

See CLUTCH article

Defective clutch master

Replace master cylinder

Defective clutch slave

Replace slave cylinder

Air in hydraulic system

Bleed hydraulic system

2008 Chevrolet Silverado 1500

GENERAL INFORMATION Trouble Shooting - Basic Procedures

Rattling

Weak or broken release lever spring

Replace spring and check

alignment

Damaged pressure plate

Replace pressure plate

Broken clutch return spring

Replace return spring

Worn splines on clutch disc or input shaft

Replace clutch disc and/or

input shaft

Worn clutch release bearing

Replace release bearing

Dry or worn pilot bearing

Lubricate or replace pilot

bearing

Unequal release lever contact

Align or replace release lever

Incorrect pedal free play

Adjust free play

Warped or damaged clutch disc

Replace damaged

components

Slipping

Pressure springs worn or

Release pressure plate

Oily, greasy or worn facings

Clean or replace clutch disc

Incorrect clutch alignment

Realign clutch assembly

Warped clutch disc or pressure plate

Replace damaged

components

Binding release levers or clutch pedal

Lubricate and/or replace

release components

Squeaking

Worn or damaged release

Replace release bearing

Dry or worn pilot or release bearing

Lubricate or replace

assembly

Pilot bearing turning in crankshaft

Replace pilot bearing and/or

crankshaft

Worn input shaft bearing

Replace bearing and seal

Incorrect transmission alignment

Realign transmission

Dry release fork between pivot

Lubricate release fork and

pivot

Heavy and/or Stiff Pedal

Sticking release bearing sleeve

Replace release bearing

and/or sleeve

Dry or binding clutch pedal hub

Lubricate and align

2008 Chevrolet Silverado 1500

GENERAL INFORMATION Trouble Shooting - Basic Procedures