1988 Ford Mustang Manual Transmission

The 1988 Ford Mustang featured a robust manual transmission system available in various models including the LX, GT, and special editions. The standard manual transmission was the Borg-Warner T-5 5-speed, known for its durability and smooth shifting performance. Below are key sections covering specifications, operation, maintenance, troubleshooting, and repair procedures.

1. Transmission Specifications 2. Gear Ratios and Shift Patterns 3. Operation Guidelines 4. Fluid Requirements 5. Maintenance Schedule 6. Clutch System 7. Common Issues 8. Troubleshooting 9. Repair Procedures 10. Parts and Components

Transmission Specifications

The 1988 Mustang manual transmission system featured the Borg-Warner T-5 5-speed as standard equipment across most models.

Component	Specification
Transmission Model	Borg-Warner T-5 5-speed
Case Material	Aluminum alloy
Gear Count	5 forward, 1 reverse
Input Shaft	10 spline, 1.125" diameter
Output Shaft	28 spline
Weight	Approximately 75 lbs (dry)
Fluid Capacity	3.0 quarts (2.8 liters)
Recommended Fluid	Mercon ATF or 75W-90 gear oil
Shift Lever	Console-mounted with reverse lockout

Gear Ratios and Shift Patterns

Standard gear ratios for the T-5 transmission in 1988 Mustang applications.

Gear	Ratio	Speed Range
1st	3.35:1	0-25 mph
2nd	1.99:1	15-45 mph
3rd	1.33:1	30-65 mph
4th	1.00:1	45-85 mph
5th	0.68:1	55+ mph (overdrive)
Reverse	3.15:1	N/A

Shift Pattern: H-pattern with reverse in lower right position (push down to engage)

Operation Guidelines

Proper manual transmission operation techniques for optimal performance and longevity.

Starting Procedure: Depress clutch fully, shift to neutral, start engine.
First Gear Engagement: Clutch in, shift to 1st, gradual clutch release with throttle.
Upshifting: Clutch in, shift to next gear, release clutch smoothly.
Downshifting: Clutch in, shift to lower gear, rev-match if necessary.
Reverse Engagement: Complete stop, push shift lever down, then left and up.
Hill Starts: Use parking brake for assistance on steep inclines.

WARNING! Do not rest hand on shift lever while driving; avoid forced shifts.

Fluid Requirements

Transmission fluid specifications and change intervals.

Fluid Type: Mercon ATF or 75W-90 GL-5 gear oil
Capacity: 3.0 quarts (2.8 liters)
Change Interval: Every 30,000 miles or 24 months
Drain Plug: 3/8" square drive, located on passenger side
Fill Plug: 3/8" square drive, driver side above drain
Inspection: Check for leaks at seals and drain/fill plugs

CAUTION! Use only recommended fluids; improper lubricants can cause premature wear.

Maintenance Schedule

Routine maintenance procedures for transmission longevity.

Service	Interval	Procedure
Fluid Check	Every 7,500 miles	Inspect level at fill plug
Fluid Change	30,000 miles	Drain and refill with new fluid
Clutch Adjustment	15,000 miles	Check free play at pedal
Shift Linkage	15,000 miles	Lubricate and check for wear
Transmission Mount	30,000 miles	Inspect for cracks/deterioration

Clutch System

The clutch system specifications and operation details.

Clutch Type: Single dry disc, diaphragm spring
Disc Diameter: 10.0 inches
Spline Count: 10 splines, 1.125" diameter
Pedal Free Play: 1.0-1.5 inches at pedal pad
Hydraulic System: Master cylinder and slave cylinder
Fluid Type: DOT 3 brake fluid
Adjustment: Self-adjusting; check pedal free play

WARNING! Do not ride clutch pedal; ensure complete disengagement when shifting.

Common Issues

Typical problems encountered with 1988 Mustang manual transmissions.

Issue	Symptoms	Common Causes
Hard Shifting	Difficulty engaging gears	Worn synchronizers, low fluid
Gear Grinding	Grinding noise during shifts	Worn clutch, damaged synchros
Transmission Noise	Whining or grinding in gear	Worn bearings, low fluid level
Leaking Fluid	Fluid on garage floor	Failed seals, loose drain plug
Stuck in Gear	Cannot shift out of gear	Shift linkage issues, internal damage

Troubleshooting

Diagnostic procedures for common transmission problems.

Symptom	Possible Cause	Corrective Action
Hard to shift into gear	Clutch not disengaging fully	Check clutch hydraulic system, adjust pedal
Gears pop out	Worn shift forks or detents	Inspect internal components, replace worn parts
Whining noise	Worn bearings or gears	Check fluid level, inspect for metal particles
Vibration in gear	Worn U-joints or output shaft	Inspect driveshaft and transmission mounts
Fluid leaks	Failed seals or gaskets	Identify leak source, replace seals

Repair Procedures

Basic repair and replacement procedures for common issues.

Fluid Change: Remove fill plug, drain plug, drain fluid, refill until fluid runs out fill hole.
Clutch Replacement: Remove transmission, replace clutch components, reassemble.
Shift Linkage Adjustment: Loosen adjustment bolts, set neutral position, tighten.
Seal Replacement: Remove driveshaft, pry out old seal, install new seal.
Transmission Removal: Disconnect driveshaft, shift linkage, clutch hydraulics, remove bolts.

CAUTION! Transmission is heavy; use proper lifting equipment and safety procedures.

Parts and Components

Key replacement parts and their specifications.

Transmission Rebuild Kit: Includes bearings, seals, gaskets, synchronizers
Clutch Kit: Disc, pressure plate, throwout bearing, alignment tool
Shift Lever Bushings: Polyurethane or OEM rubber replacements
Transmission Mount: Rubber isolator between transmission and crossmember
Speedometer Gear: Plastic gear on output shaft (various tooth counts)
Backup Light Switch: Located on transmission case

Service: For technical support, contact Ford Customer Service or certified transmission specialists.