1986 F250 5 Speed Manual Transmission

The 1986 Ford F250 featured a robust 5-speed manual transmission designed for heavy-duty towing and hauling applications. This transmission was known for its durability and reliability in work truck applications. Below are key sections covering specifications, operation, maintenance, troubleshooting, and service information.

1. Transmission Specifications 2. Gear Ratios and Shift Pattern 3. Operation and Driving Tips 4. Maintenance Schedule 5. Fluid Requirements 6. Common Issues and Troubleshooting 7. Clutch System 8. Transmission Removal and Installation 9. Rebuild Procedures 10. Parts and Components 11. Technical Service Bulletins

Transmission Specifications

The 1986 F250 5-speed manual transmission was designed for heavy-duty applications with various engine options.

Specification	Details
Transmission Model	Ford T-19 4-speed or ZF S5-42 5-speed
Type	Manual, synchronized (2nd through 5th)
Case Material	Cast iron
Input Shaft Spline	10-tooth, 1.375" diameter
Output Shaft	31-tooth spline
Length	Approximately 24.5 inches
Weight	Approximately 125 lbs (dry)
Fluid Capacity	4.5 quarts (4.3 liters)
Recommended Fluid	80W-90 GL-4 Gear Oil
Bolt Pattern	Ford standard truck pattern

Gear Ratios and Shift Pattern

Understanding the gear ratios and proper shift pattern is essential for optimal performance and fuel economy.

First Gear: 6.69:1 (granny low) or 4.02:1 (direct)
Second Gear: 3.34:1
Third Gear: 1.79:1
Fourth Gear: 1.00:1 (direct)
Fifth Gear: 0.76:1 (overdrive)
Reverse: 6.54:1

Shift Pattern: H-pattern with reverse left and up

WARNING! Always come to complete stop before shifting into reverse to prevent gear damage.

Operation and Driving Tips

Proper operation extends transmission life and improves performance.

Double-clutch when downshifting for smoother engagement
Allow complete clutch engagement before applying heavy throttle
Use first gear only for heavy loads or steep inclines
Avoid "riding" the clutch pedal
Use engine braking on steep descents
Shift at recommended RPM ranges (2000-3000 RPM for normal driving)

CAUTION! Do not force shifts; if gear won't engage, check clutch adjustment.

Maintenance Schedule

Every 3,000 miles: Check transmission fluid level
Every 30,000 miles: Change transmission fluid
Every 15,000 miles: Inspect clutch hydraulic system
Every 50,000 miles: Inspect transmission mounts
As needed: Adjust clutch pedal free play
Annually: Lubricate shift linkage and components

Fluid Requirements

Proper fluid selection is critical for transmission longevity and performance.

Recommended: 80W-90 GL-4 Gear Oil (4.5 quarts)

Alternative: 75W-90 Synthetic Gear Oil for extreme temperatures

WARNING: Do not use GL-5 gear oil as it can damage synchronizers

Park on level surface
Remove fill plug (side of transmission case)
Add fluid until it reaches bottom of fill hole
Replace fill plug and tighten securely

Common Issues and Troubleshooting

Identifying and addressing common transmission problems.

Symptom	Possible Cause	Corrective Action
Hard shifting	Worn synchronizers, incorrect fluid	Change to proper GL-4 fluid; inspect synchronizers
Gear grinding	Clutch not disengaging fully	Adjust clutch pedal; check master/slave cylinder
Transmission jumps out of gear	Worn shift forks or detents	Inspect internal components; replace worn parts
Fluid leaks	Worn seals or gaskets	Replace input/output shaft seals; check case gasket
Noise in neutral	Input shaft bearing wear	Replace input shaft bearing and seal
Vibration	Worn transmission mount	Replace transmission mount; check driveshaft alignment

Clutch System

The clutch system works in conjunction with the 5-speed transmission.

Clutch Type: 11-inch diaphragm spring
Hydraulic System: Master and slave cylinder
Pedal Free Play: 1-1.5 inches at top of pedal travel
Recommended Replacement: Every 60,000-100,000 miles

Adjustment Procedure: Bleed hydraulic system; adjust pedal free play; check for proper disengagement.

Transmission Removal and Installation

Step-by-step procedure for transmission removal and installation.

Disconnect battery negative cable
Remove shift lever and boot
Support transmission with jack
Remove driveshaft and exhaust components as needed
Disconnect clutch hydraulic line and speedometer cable
Remove crossmember and transmission mount
Lower transmission and remove from vehicle
Reverse procedure for installation

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

Rebuild Procedures

Basic rebuild procedures for the 5-speed transmission.

Disassemble transmission on clean work surface
Inspect all gears for wear and chipping
Check synchronizer rings for wear
Replace all bearings and seals
Inspect shift forks and detents
Assemble with proper clearances and lubrication
Test shift operation before installation

Parts and Components

Essential replacement parts and components.

Part	Part Number	Description
Input Shaft Seal	E5TZ-7052-A	Front transmission seal
Output Shaft Seal	E6TZ-4676-A	Rear transmission seal
Shift Lever	E5TZ-7210-A	Transmission shift lever
Transmission Mount	E6TZ-6068-A	Rubber transmission mount
Drain Plug	N802055-S	Magnetic drain plug
Fill Plug	N802055-S	Transmission fill plug

Technical Service Bulletins

Important service information and updates.

TSB 86-15-03: Updated shift linkage adjustment procedure

TSB 87-8-11: Revised clutch hydraulic bleeding procedure

TSB 88-12-07: Synchronizer improvement kit availability

TSB 89-4-15: Transmission mount reinforcement

Service Support: Contact Ford Motor Company Service Division for technical assistance and parts availability.