1986 Toyota MR2 Manual Transmission

The 1986 Toyota MR2 features a 5-speed manual transmission (C50/C52 series) with mid-engine, rear-wheel-drive layout. This manual covers the S-series transmission specifications, shift patterns, clutch system, maintenance procedures, troubleshooting, and repair guidelines for the 1986 model year MR2 with 1.6L 4A-GE engine. Below are key sections covering operation, maintenance, specifications, and common issues.

1. Transmission Specifications 2. Shift Pattern & Operation 3. Clutch System 4. Fluid Requirements 5. Maintenance Schedule 6. Troubleshooting Common Issues 7. Transmission Removal & Installation 8. Gear Ratios 9. Synchro Service 10. Warranty & Support 11. Technical Service Bulletins

Transmission Specifications

The 1986 MR2 uses C50/C52 5-speed manual transmission with the following specifications:

Component	Specification
Transmission Type	C50/C52 5-speed manual
Gear Ratios	1st: 3.166, 2nd: 1.904, 3rd: 1.310, 4th: 0.969, 5th: 0.815, Reverse: 3.250
Final Drive Ratio	4.312:1
Fluid Capacity	2.2 quarts (2.1 liters)
Fluid Type	75W-90 GL-4 or GL-5 gear oil
Clutch Type	Hydraulic, single dry disc
Shift Linkage	Direct cable-operated
Case Material	Aluminum alloy
Weight	Approximately 75 lbs (34 kg)
Manufacturer	Aisin Warner

Shift Pattern & Operation

Standard H-pattern 5-speed manual transmission with reverse lockout.

Familiarize with shift pattern: R-1-3-5 pattern with reverse left and up.
Reverse engagement: Press down on shift knob and move left then up.
Smooth shifting: Use clutch fully; avoid forcing gears.
Recommended shift points: 1-2: 15 mph, 2-3: 25 mph, 3-4: 40 mph, 4-5: 55 mph.

WARNING! Do not shift into reverse while moving forward. Always come to complete stop before reverse engagement.

Clutch System

Hydraulic clutch system with master cylinder, slave cylinder, and clutch disc.

Clutch pedal free play: 0.2-0.6 inches (5-15mm) at pedal pad.
Clutch fluid: DOT 3 brake fluid; check reservoir level monthly.
Bleeding procedure: Two-person method recommended for air removal.
Clutch disc thickness: New 8.5mm, replace if below 7.0mm.

CAUTION! Avoid riding clutch pedal; this causes premature wear of clutch components.

Fluid Requirements

Transmission Fluid: 75W-90 GL-4 or GL-5 gear oil, 2.2 quarts capacity.
Change Interval: Every 30,000 miles or 24 months under normal conditions.
Fluid Type: Synthetic gear oil recommended for improved shifting in cold weather.
Drain Plug: Magnetic; clean during fluid changes.
Fill Plug: 24mm hex head; located on driver's side of transmission case.
Inspection: Check for leaks at seals and drain/fill plugs regularly.

Maintenance Schedule

Regular maintenance ensures optimal transmission performance and longevity.

Every 5,000 miles: Check transmission fluid level, inspect for leaks.

Every 30,000 miles: Change transmission fluid, inspect clutch components.

Every 60,000 miles: Replace clutch hydraulic fluid, inspect shift linkage bushings.

As needed: Adjust clutch pedal free play, check transmission mounts.

Troubleshooting Common Issues

Common transmission-related problems and solutions:

Symptom	Possible Cause	Corrective Action
Difficulty shifting	Low fluid, worn synchros	Check fluid level; if low, top up and inspect for leaks. If synchros worn, transmission rebuild may be needed.
Grinding gears	Clutch not disengaging fully	Check clutch hydraulic system; bleed if necessary. Adjust clutch pedal free play.
Transmission noise	Low fluid, worn bearings	Check fluid level and condition. If bearings worn, professional service required.
Fluid leaks	Worn seals, loose plugs	Identify leak source; replace seals or tighten plugs as needed.
Clutch slippage	Worn clutch disc	Replace clutch disc, pressure plate, and throwout bearing.

Transmission Removal & Installation

Procedure for removing and installing transmission (professional recommended):

Disconnect battery negative terminal.
Remove air intake and other components obstructing transmission access.
Support engine with jack or engine support fixture.
Remove driveshafts, shift linkage, and clutch hydraulic line.
Remove transmission mounting bolts and lower transmission carefully.
Installation is reverse of removal; torque bolts to specification.

WARNING! Transmission is heavy; use proper lifting equipment. Follow torque specifications precisely.

Gear Ratios

Detailed gear ratios for optimal performance understanding:

Gear	Ratio	Approx. Speed at 6000 RPM
1st	3.166:1	31 mph
2nd	1.904:1	52 mph
3rd	1.310:1	75 mph
4th	0.969:1	102 mph
5th	0.815:1	121 mph
Reverse	3.250:1	N/A

Synchro Service

Synchronizer maintenance and replacement guidelines:

Symptoms of worn synchros: Difficulty shifting into gear, grinding during shifts.
Inspection: Requires transmission disassembly.
Replacement: Replace synchro rings, baulk rings, and related components as set.
Lubrication: Use specified gear oil for proper synchro function.

Note: Synchro service typically requires transmission removal and professional expertise.

Warranty & Support

Original warranty: 12 months/12,000 miles from date of purchase. Contact Toyota dealership for warranty claims. For technical support, refer to Toyota Technical Service Bulletins or contact Toyota Customer Experience Center at 1-800-331-4331.

Technical Service Bulletins

Common TSBs for 1986 MR2 manual transmission:

TSB 86-001: Updated shift linkage adjustment procedure
TSB 86-015: Revised clutch master cylinder specification
TSB 86-028: Improved transmission mount design
TSB 86-042: Synchro material update for 2nd and 3rd gears

Service Information: Contact Toyota dealership for TSB details and updates.