1986 Ford Bronco Manual Transmission
The 1986 Ford Bronco featured a robust manual transmission system designed for off-road capability and reliable performance. This manual covers the Borg-Warner T-18/T-19 4-speed manual transmission options available for the 1986 Bronco, including specifications, operation, maintenance procedures, troubleshooting, and repair guidelines for optimal transmission performance and longevity.
Transmission Specifications
The 1986 Ford Bronco manual transmission system featured heavy-duty construction for off-road use and towing capability.
| Component | Specification |
|---|
| Transmission Model | Borg-Warner T-18/T-19 4-speed |
| Gear Ratios | 1st: 6.32:1, 2nd: 3.09:1, 3rd: 1.69:1, 4th: 1.00:1 |
| Reverse Ratio | 7.44:1 |
| Case Material | Cast iron |
| Lubricant Capacity | 4.75 pints (2.25 liters) |
| Lubricant Type | 80W-90 GL-4 Gear Oil |
| Shift Type | Floor-mounted 3-speed column with overdrive |
| Clutch Type | 11-inch diaphragm spring |
| Synchronizers | 2nd, 3rd, and 4th gears |
| Transfer Case | Borg-Warner 1345 part-time 4WD |
Gear Ratios and Operation
Understanding proper gear selection and operation for various driving conditions.
- First Gear (6.32:1): Use for heavy loads, steep inclines, or off-road crawling
- Second Gear (3.09:1): General starting gear for normal conditions
- Third Gear (1.69:1): Highway cruising and moderate acceleration
- Fourth Gear (1.00:1): Direct drive for fuel economy at highway speeds
- Reverse (7.44:1): Low gear ratio for controlled backing with loads
WARNING! Do not force shifts between gears; always use clutch fully. Avoid "grinding" gears during shifts.
Clutch System
The clutch system provides smooth engagement between engine and transmission.
- Clutch Pedal: Hydraulic actuation with self-adjusting mechanism
- Clutch Disc: 11-inch diameter, organic facing material
- Pressure Plate: Diaphragm spring type, 2400 lb clamp load
- Throwout Bearing: Graphite composition, self-lubricating
- Master Cylinder: 3/4-inch bore, mounted on firewall
- Slave Cylinder: 7/8-inch bore, mounted on bellhousing
CAUTION! Proper clutch adjustment is critical to prevent premature wear and transmission damage.
Fluid Requirements
- Transmission Fluid: 80W-90 GL-4 Gear Oil (4.75 pints)
- Transfer Case Fluid: ATF Dexron II/Mercon (3.0 pints)
- Change Interval: Every 30,000 miles or 24 months
- Inspection: Check for leaks monthly
- Fluid Type Warning: Do not use GL-5 gear oil - can damage synchronizers
- Drain Plug: 3/8-inch square drive, magnetic
- Fill Plug: 1/2-inch square drive, located on side case
Shift Pattern and Operation
Standard H-pattern shift configuration with reverse lock-out mechanism.
Shift Pattern:
R 2 4
| | |
| 1 | 3 |
Operation: Fully depress clutch pedal before shifting. Reverse gear requires lifting collar on shift knob. Synchronized on 2nd, 3rd, and 4th gears only. Double-clutching recommended for downshifts to 1st gear.
Maintenance Schedule
Regular maintenance ensures long transmission life and reliable operation.
- Daily: Check for fluid leaks under vehicle
- Monthly: Inspect clutch fluid level in reservoir
- Every 15,000 miles: Check transmission fluid level
- Every 30,000 miles: Change transmission and transfer case fluids
- Every 60,000 miles: Inspect clutch components and shift linkage
- As needed: Adjust clutch pedal free play (1-1.5 inches)
Tip: Always use factory-specified fluids to maintain warranty and performance.
Common Issues
Typical problems encountered with 1986 Bronco manual transmissions.
- Hard shifting: Usually caused by worn synchronizers or incorrect fluid
- Gear grinding: Indicates clutch not fully disengaging or synchronizer wear
- Jumping out of gear: Worn shift forks or detent springs
- Fluid leaks: From rear seal, shift lever seals, or case halves
- Noise in neutral: Typically pilot bearing or input shaft bearing
- Clutch chatter: Oil contamination or warped pressure plate
- Difficulty engaging reverse: Common with worn reverse idler gear
WARNING! Continuing to drive with transmission problems can cause catastrophic failure.
Troubleshooting Guide
| Symptom | Possible Cause | Corrective Action |
|---|
| Hard to shift into gear | Low clutch fluid, air in system | Bleed clutch hydraulic system, check master cylinder |
| Gears grind when shifting | Worn synchronizers, clutch adjustment | Adjust clutch pedal, inspect synchronizers |
| Transmission jumps out of gear | Worn shift forks, detent springs | Replace worn components, check shift linkage |
| Fluid leak from transmission | Worn seals, cracked case | Replace rear main seal, inspect case for cracks |
| Noise in neutral with clutch out | Input shaft bearing wear | Replace input shaft bearing and seal |
| Vehicle creeps with clutch depressed | Clutch drag, hydraulic issues | Bleed system, check clutch disc for warping |
Repair Procedures
Basic repair procedures for common transmission issues.
- Fluid Change: Drain old fluid, refill with specified 80W-90 GL-4
- Clutch Replacement: Remove transmission, replace clutch components
- Seal Replacement: Remove drive shaft, replace rear seal
- Shift Linkage Adjustment: Adjust rods for proper gear engagement
- Bearing Replacement: Requires transmission disassembly
- Synchro Replacement: Complete transmission overhaul needed
CAUTION! Transmission repair requires special tools and expertise. Consult professional mechanic for complex repairs.
Parts and Components
- Transmission Assembly: Borg-Warner T-18/T-19 4-speed
- Clutch Kit: 11-inch disc, pressure plate, throwout bearing
- Seals: Rear main seal, input shaft seal, shift lever seals
- Gaskets: Case half gasket, side cover gasket
- Bearings: Input shaft, output shaft, countershaft bearings
- Synchronizers: 2nd/3rd gear synchro assembly, 4th gear synchro
- Shift Components: Shift forks, detent springs, interlock pins
Service: Contact Ford dealership or qualified transmission specialist for parts and service.
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