1987 Dodge W150 Manual Transmission

The 1987 Dodge W150 features a rugged manual transmission system designed for heavy-duty performance and reliability. This 4x4 pickup truck comes equipped with either a 4-speed or 5-speed manual transmission option, providing excellent torque control and durability for both on-road and off-road applications. Below are key sections covering specifications, operation, maintenance, troubleshooting, and service procedures.

1. Transmission Specifications 2. Gear Ratios and Operation 3. Clutch System 4. Fluid Requirements 5. Shift Pattern 6. Maintenance Schedule 7. Troubleshooting Common Issues 8. Transmission Removal and Installation 9. 4WD System Integration 10. Warranty and Service Information 11. Technical Support

Transmission Specifications

The 1987 Dodge W150 manual transmission is built for durability and heavy-duty performance.

SpecificationDetails
Transmission TypeManual 4-speed or 5-speed
Model CodesNP435 (4-speed), NP445 (5-speed)
Case MaterialCast iron
Gear TypeHelical cut gears (2nd-4th/5th)
Synchronizers2nd, 3rd, 4th, and 5th gears
Input Shaft10-spline, 1-1/8" diameter
Output Shaft23-spline
LengthApproximately 24.5 inches
WeightApproximately 125 lbs
Compatible Engines318ci V8, 360ci V8

Gear Ratios and Operation

Understanding the gear ratios and proper shifting technique ensures optimal performance and longevity.

  1. 4-Speed Transmission Ratios: 1st: 6.69:1, 2nd: 3.34:1, 3rd: 1.66:1, 4th: 1.00:1
  2. 5-Speed Transmission Ratios: 1st: 5.61:1, 2nd: 3.03:1, 3rd: 1.67:1, 4th: 1.00:1, 5th: 0.81:1
  3. Reverse Gear Ratio: 6.69:1 (4-speed), 5.61:1 (5-speed)
  4. Proper Shifting: Always depress clutch fully; avoid forcing gears; use smooth, deliberate shifts

WARNING! Do not rest hand on shift lever while driving; this can cause premature wear on transmission components.

Clutch System

The clutch system provides smooth engagement between engine and transmission.

CAUTION! Proper clutch adjustment is critical; excessive free play can cause incomplete disengagement.

Fluid Requirements

Proper lubrication is essential for transmission longevity and performance.

Fluid TypeCapacityChange Interval
Manual Transmission Fluid3.5 quartsEvery 30,000 miles
Recommended GradeSAE 80W-90 GL-4Do not use GL-5
Transfer Case Fluid2.5 pintsEvery 15,000 miles
Differential Fluid4.0 pints (front), 5.5 pints (rear)Every 30,000 miles

NOTE: GL-5 gear oil can damage brass synchronizers; use only GL-4 specification.

Shift Pattern

Familiarize yourself with the transmission shift pattern for safe operation.

4-Speed Pattern:

5-Speed Pattern:

Maintenance Schedule

Regular maintenance ensures long transmission life and reliable performance.

  1. Daily: Check for fluid leaks under vehicle
  2. Monthly: Inspect clutch pedal free play and adjust if necessary
  3. Every 15,000 miles: Change transfer case fluid
  4. Every 30,000 miles: Change transmission and differential fluids
  5. Every 60,000 miles: Inspect clutch components for wear
  6. As needed: Lubricate shift linkage and clutch linkage points

Tip: Keep transmission breather tubes clear to prevent water intrusion.

Troubleshooting Common Issues

Address common transmission problems with these diagnostic steps.

SymptomPossible CauseCorrective Action
Hard shiftingWorn synchronizers, incorrect fluidChange to proper GL-4 fluid; inspect synchronizers
Gear grindingClutch not disengaging fullyAdjust clutch linkage; check hydraulic system
Transmission jumps out of gearWorn shift forks or detentsInspect internal components; replace worn parts
Noise in neutralWorn input shaft bearingReplace input shaft bearing
Noise in gearWorn countershaft bearingsReplace countershaft bearings
Fluid leaksWorn seals or gasketsReplace output shaft seal, input shaft seal, or side cover gasket

Transmission Removal and Installation

Proper procedure for removing and installing the manual transmission.

  1. Disconnect battery negative cable
  2. Remove shift lever and boot
  3. Support transmission with jack
  4. Disconnect driveshafts and speedometer cable
  5. Disconnect clutch linkage or hydraulic line
  6. Remove transmission crossmember
  7. Support engine with jack or hoist
  8. Remove transmission-to-bellhousing bolts
  9. Slide transmission rearward and lower from vehicle
  10. Reverse procedure for installation

WARNING! Transmission is heavy; use proper lifting equipment and assistance.

4WD System Integration

The manual transmission works in conjunction with the NP208 transfer case.

CAUTION! Do not operate in 4WD on dry pavement; this can cause driveline binding and damage.

Warranty and Service Information

Original warranty coverage and service recommendations.

Original Warranty: 5 years/50,000 miles (whichever comes first) from original purchase date. Coverage includes defects in materials and workmanship. Normal wear items, abuse, and improper maintenance are not covered.

Service Intervals: Follow maintenance schedule outlined in section 7. Use only Mopar or equivalent quality replacement parts.

Technical Support

Resources for additional assistance and technical information.

Note: This transmission is known for durability; many units exceed 200,000 miles with proper maintenance.

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