1988 Ford Bronco 2 Manual Transmission

The 1988 Ford Bronco II features a manual transmission system designed for rugged off-road performance and reliable daily driving. This compact SUV comes equipped with a 5-speed manual transmission paired with either the 2.9L V6 or 2.3L 4-cylinder engine options. Below are key sections covering specifications, operation, maintenance, troubleshooting, and repair procedures.

1. Transmission Specifications 2. Gear Shift Pattern 3. Clutch System 4. Fluid Requirements 5. Driving Operation 6. Maintenance Schedule 7. Common Issues 8. Troubleshooting 9. Repair Procedures 10. Warranty Information

Transmission Specifications

The 1988 Bronco II manual transmission is a heavy-duty unit designed for durability.

Component	Specification
Transmission Type	5-speed manual overdrive
Model Code	Mitsubishi FM146 or TK5
Gear Ratios	1st: 3.90, 2nd: 2.25, 3rd: 1.46, 4th: 1.00, 5th: 0.85, Reverse: 3.79
Fluid Capacity	3.5 quarts (3.3L) of Mercon ATF
Case Material	Aluminum alloy
Synchronizers	Carbon-lined synchronizers on all forward gears
Shift Linkage	Direct floor-mounted shifter
Transfer Case	BorgWarner 13-50 part-time 4WD (4x4 models)

Gear Shift Pattern

Standard H-pattern shift configuration with reverse lockout.

Reverse position: Push down on shift knob and move left-forward
1st gear: Far left and forward position
2nd gear: Far left and backward position
3rd gear: Center and forward position
4th gear: Center and backward position
5th gear: Far right and forward position

NOTE! Always come to complete stop before engaging reverse gear. Use clutch fully when shifting.

Clutch System

Hydraulic clutch system with self-adjusting mechanism.

Clutch Type: Single dry disc, diaphragm spring
Clutch Disc Diameter: 9.25 inches (235mm)
Fluid Type: DOT 3 brake fluid
Master Cylinder: 3/4 inch bore
Slave Cylinder: 7/8 inch bore
Pedal Free Play: 1/2 to 1 inch (12-25mm)

WARNING! Do not ride clutch pedal; replace fluid every 30,000 miles.

Fluid Requirements

Proper fluid maintenance ensures transmission longevity.

Check fluid level: Remove fill plug on transmission side
Drain and refill: Every 30,000 miles under normal conditions
Fluid type: Mercon Automatic Transmission Fluid (ATF)
Capacity: 3.5 quarts (fill until fluid reaches bottom of fill hole)
4WD models: Transfer case requires 2.2 pints of Mercon ATF

CAUTION! Use only specified fluids; incorrect fluid can damage synchronizers.

Driving Operation

Proper shifting techniques for optimal performance.

Normal Driving: Shift between 2000-3000 RPM for fuel economy. Off-Road: Use lower gears (1st-2nd) for steep terrain. Towing: Use 4th gear for highway towing; avoid 5th gear.

Shifting Procedure: Depress clutch fully, move shifter firmly but smoothly, release clutch gradually while applying throttle. Double-clutching recommended for downshifting.

Maintenance Schedule

Regular maintenance prevents premature wear.

Interval	Service Required
Every 3,000 miles	Check transmission fluid level
Every 30,000 miles	Drain and refill transmission fluid
Every 15,000 miles	Inspect clutch hydraulic system
Every 60,000 miles	Replace clutch fluid
As needed	Adjust clutch pedal free play
Every 50,000 miles	Lubricate shift linkage components

Common Issues

Typical problems encountered with this transmission.

Hard Shifting: Worn synchronizers or incorrect fluid
Gear Grinding: Low fluid level or clutch adjustment needed
Jumping Out of Gear: Worn shift forks or detent springs
Fluid Leaks: Worn seals at output shaft or shift levers
Noisy Operation: Worn bearings or insufficient lubrication
Clutch Slippage: Worn clutch disc or pressure plate

Troubleshooting

Symptom	Possible Cause	Corrective Action
Hard to shift into gear	Low fluid, worn clutch	Check fluid level; inspect clutch system; adjust linkage
Gear grinding noise	Synchronizer wear	Replace synchronizers; use correct fluid type
Transmission jumps out of gear	Worn shift forks	Replace shift forks and detent springs
Fluid leakage	Seal failure	Replace output shaft seal or shift lever seals
Vibration in gear	U-joints or mounts	Inspect U-joints; replace transmission mounts
Unable to select reverse	Reverse lockout	Check reverse lockout mechanism; adjust shift linkage

Repair Procedures

Basic repair steps for common transmission issues.

Fluid Change: Remove drain plug, drain old fluid, reinstall plug, add new fluid until it reaches fill hole
Clutch Replacement: Remove transmission, replace clutch disc and pressure plate, resurface flywheel
Seal Replacement: Remove driveshaft, pry out old seal, install new seal with proper driver tool
Shift Linkage Adjustment: Loosen adjustment bolts, position shifter in neutral, tighten bolts
Transmission Removal: Disconnect driveshafts, shift linkage, clutch hydraulic line, remove crossmember, lower transmission

WARNING! Always support vehicle securely with jack stands when working underneath.

Warranty Information

Original warranty coverage and service recommendations.

1988 Ford Bronco II manual transmissions were covered by Ford's 12-month/12,000-mile basic warranty. Current vehicles are well beyond factory coverage. For technical support or replacement parts, contact Ford Customer Service at 1-800-392-3673 or visit www.ford.com. Reproduction of this manual is prohibited without written permission from Ford Motor Company.