1987 F250 Manual Transmissions

The 1987 Ford F250 was available with several manual transmission options designed for heavy-duty truck applications. These transmissions were built to handle the torque output of Ford's engine lineup while providing reliable shifting performance for both work and daily driving. Below are key sections covering transmission types, specifications, operation, maintenance, and troubleshooting.

1. Transmission Models 2. Technical Specifications 3. Installation Guidelines 4. Operation Instructions 5. Maintenance Schedule 6. Fluid Requirements 7. Troubleshooting 8. Common Issues 9. Repair Procedures 10. Parts Identification

Transmission Models

The 1987 F250 featured several manual transmission options depending on engine configuration and intended use.

Transmission Model	Description
T-18	4-speed heavy-duty transmission with granny low gear
T-19	4-speed transmission with synchronized 2nd, 3rd, and 4th gears
NP435	New Process 4-speed with compound low gear
ZF S5-42	5-speed overdrive transmission for improved fuel economy
BorgWarner T-18	4-speed with 6.32:1 first gear ratio

Technical Specifications

Gear Ratios (T-18): 1st: 6.32:1, 2nd: 3.09:1, 3rd: 1.69:1, 4th: 1.00:1
Gear Ratios (ZF S5-42): 1st: 5.72:1, 2nd: 2.94:1, 3rd: 1.61:1, 4th: 1.00:1, 5th: 0.76:1
Case Material: Cast iron housing
Input Shaft: 1-1/8" 10-spline
Output Shaft: Varies by model and transfer case configuration
Weight: Approximately 120-140 lbs depending on model
Fluid Capacity: 3-4 quarts of gear oil

Installation Guidelines

Proper transmission installation requires careful alignment and secure mounting.

Support transmission with jack and align input shaft with clutch disc
Ensure clutch alignment tool is properly positioned
Install transmission mounting bolts and torque to specification (45-55 ft-lbs)
Connect shift linkage and verify proper operation
Fill with recommended transmission fluid

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

Operation Instructions

Proper shifting technique ensures long transmission life.

Depress clutch pedal fully before shifting
Use first gear only for heavy loads or steep inclines
Allow RPM to match before engaging next gear
Do not rest hand on shift lever during normal driving
Use appropriate gear for road speed and load conditions

CAUTION! Avoid forced shifting or grinding gears as this causes premature wear.

Maintenance Schedule

Regular maintenance ensures optimal transmission performance and longevity.

Service Interval	Maintenance Task
Every 30,000 miles	Check transmission fluid level and condition
Every 60,000 miles	Change transmission fluid and inspect for metal particles
As needed	Inspect shift linkage for wear and proper adjustment
Every 100,000 miles	Complete transmission inspection and seal replacement

Fluid Requirements

Proper fluid selection is critical for transmission operation and protection.

Recommended Fluid: 80W-90 GL-5 Gear Oil
Alternative: 75W-90 Synthetic Gear Oil for extreme temperatures
Capacity: 3.5 quarts (check fill plug for exact level)
Change Interval: 60,000 miles under normal conditions
Do Not Use: Automatic transmission fluid or engine oil

Troubleshooting

Common transmission problems and their solutions.

Symptom	Possible Cause	Corrective Action
Hard shifting	Low fluid, worn synchronizers	Check fluid level, inspect synchronizer rings
Gear grinding	Clutch not disengaging fully	Adjust clutch linkage, check master cylinder
Transmission noise	Worn bearings, low fluid	Check fluid, inspect bearings for wear
Jumping out of gear	Worn shift forks, detent springs	Inspect internal shift mechanism
Fluid leaks	Worn seals, cracked case	Replace seals, repair case damage

Common Issues

Known problems with 1987 F250 manual transmissions and recommended solutions.

Synchronizer Wear: Common in high-mileage units; requires transmission disassembly
Shift Linkage Wear: Bushings and joints wear causing sloppy shifting
Input Shaft Bearing Noise: Whining sound in neutral that disappears when clutch depressed
Countergear Bearing Failure: Causes noise in all gears except fourth
Seal Leaks: Front and rear seals commonly leak with age

Repair Procedures

Basic repair steps for common transmission issues.

Drain transmission fluid completely
Remove transmission from vehicle using proper support
Disassemble transmission on clean work surface
Inspect all components for wear and damage
Replace worn bearings, seals, and synchronizers
Reassemble with proper clearances and lubrication
Reinstall and test operation

WARNING! Transmission repair requires special tools and expertise.

Parts Identification

Key components of 1987 F250 manual transmissions.

Part Name	Function
Input Shaft	Transmits engine power to transmission
Output Shaft	Delivers power to driveshaft
Synchronizers	Equalize shaft speeds for smooth shifting
Shift Forks	Move synchronizers to engage gears
Bearings	Support rotating shafts and reduce friction
Gears	Provide different speed ratios
Seals	Prevent fluid leaks at shaft openings