Getrag 5-speed
Getrag 5-speed refers to the five-speed manual transmission used in later V6-equipped Pontiac Fiero models.
The Getrag 5-speed was the factory five-speed manual transmission used with the 2.8L V6. It should not be confused with the Isuzu 5-speed, which was used with the 2.5L four-cylinder engine.
Overview
The Getrag 5-speed is a transverse manual transaxle used in later Fiero V6 applications.
It replaced the earlier V6 four-speed manual transmission and provided a fifth gear for improved highway cruising. In Fiero discussions, it is commonly considered the factory performance five-speed manual transmission.
The Getrag 5-speed is often desirable because it was paired with the factory 2.8L V6 and because it provides both a sporty manual transmission and a highway-friendly fifth gear.
Location
Image wanted: Photo or diagram showing the Getrag 5-speed transmission installed in a Pontiac Fiero, preferably showing the transmission case, shift cables, clutch slave cylinder, mounts, and axle locations.
The Getrag 5-speed is mounted transversely in the rear engine compartment, bolted to the engine.
It is mounted on the engine cradle and drives the rear wheels through the Fiero axle shafts.
Naming
The transmission may be referred to as:
- Getrag 5-speed
- Getrag five-speed
- Getrag manual transmission
- Getrag/Muncie 5-speed
- 5-speed manual
- V6 5-speed
In Fiero usage, “Getrag 5-speed” usually refers to the factory five-speed manual transmission used with the 2.8L V6.
Because different GM manual transaxles may share similar names or layouts, parts should be identified by the actual transmission, application, case, brackets, cables, and related hardware.
Fiero applications
The Getrag 5-speed was used with the 2.8L V6 in later Fiero production.
It is commonly associated with:
- Later V6 Fieros
- 1986 V6 Fieros after the Getrag became available
- 1987 V6 Fieros
- 1988 V6 Fieros
- GT models equipped with the five-speed manual
- 1988 Formula models equipped with the five-speed manual
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Because many Fieros have been modified or repaired over time, the installed transmission should be identified directly rather than relying only on model year, trim, or engine.
Specifications
| Specification | Getrag 5-speed |
|---|---|
| Type | Transverse manual transaxle |
| Common Fiero designation | Getrag / Muncie 5-speed |
| RPO code | MG2 |
| Speeds | 5 forward speeds |
| Reverse | Yes |
| Overdrive | Yes |
| Factory Fiero use | Later V6 models |
| Factory four-cylinder use | No |
| Clutch operation | Hydraulic |
| Shift operation | Cable-operated |
| Common Fiero role | Factory V6 five-speed manual transmission |
The Fiero Getrag 5-speed was Getrag-designed and Muncie-built. In Fiero owner discussions, it is usually called the Getrag 5-speed to distinguish it from the earlier Muncie 4-speed.
Gear ratios
The Fiero V6 Getrag 5-speed is associated with RPO code MG2.
| Gear | Ratio |
|---|---|
| 1st | 3.50 |
| 2nd | 2.05 |
| 3rd | 1.38 |
| 4th | 0.94 |
| 5th | 0.72 |
| Final drive | 3.61 |
The fifth gear is an overdrive gear and helps reduce engine rpm during highway driving compared with the earlier V6 Muncie 4-speed.
Because Fieros are often modified, repaired, or transmission-swapped, the actual installed transmission should be identified directly when exact gearing matters.
Operation
The Getrag 5-speed is a manually shifted transaxle.
The driver selects gears using the interior shifter, which operates the transmission through shift and select cables. The clutch is operated hydraulically using a clutch master cylinder, hydraulic line, and clutch slave cylinder.
The fifth gear allows lower engine rpm at highway speed than a four-speed manual transmission.
Shift cables and shifter
The Getrag 5-speed uses shift cables between the interior shifter and the transmission.
Cable condition and adjustment are important. Worn, stretched, damaged, or misadjusted cables can cause poor shifting, difficulty selecting gears, or an inability to engage certain gears.
The Getrag cable and bracket arrangement should not be assumed to interchange with the Isuzu 5-speed or Muncie 4-speed without verification.
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Clutch system
Like other manual-transmission Fieros, the Getrag 5-speed uses a hydraulic clutch system.
The clutch system includes:
- Clutch pedal
- Clutch master cylinder
- Hydraulic clutch line
- Clutch slave cylinder
- Release arm
- Clutch pressure plate and disc
- Throwout bearing
Clutch hydraulic problems can be mistaken for transmission problems.
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Common problems
Common Getrag 5-speed topics include:
- Worn or misadjusted shift cables
- Clutch hydraulic problems
- Difficulty shifting into gear
- Grinding during shifts
- Worn synchronizers
- Gear noise
- Fluid leaks
- Axle seal leaks
- Worn mounts
- Previous incorrect service
- Confusion with other five-speed transmissions
- Parts availability issues
Symptoms
Possible symptoms of Getrag 5-speed problems include:
- Hard shifting
- Gear clash or grinding
- Difficulty selecting reverse
- Difficulty selecting first gear
- Difficulty shifting into second or third gear
- Transmission pops out of gear
- Clutch does not fully disengage
- Noise while driving
- Noise that changes with gear selection
- Fluid leak
- Excessive drivetrain movement
- Shifter feels loose or vague
Diagnosis
Before assuming the transmission itself has failed, basic checks should include:
- Check clutch hydraulic operation.
- Check clutch pedal travel.
- Inspect the clutch master cylinder and slave cylinder.
- Check for air in the clutch hydraulic system.
- Inspect shift and select cables.
- Check cable adjustment and cable bracket condition.
- Inspect transmission and engine mounts.
- Check transmission fluid level and condition.
- Inspect axle seals and related leak points.
- Determine whether the problem occurs in one gear, several gears, or all gears.
- Verify that the transmission is actually a Getrag 5-speed.
A clutch that does not fully disengage can cause hard shifting or grinding even if the transmission is otherwise good.
Fluid service
The Getrag 5-speed requires the correct transmission fluid.
Fluid level and condition are important for gear and bearing life. Low, contaminated, or incorrect fluid can contribute to noise, wear, and shifting problems.
When servicing the transmission, verify the correct fluid specification for the year and transmission.
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Relationship to the Isuzu 5-speed
The Getrag 5-speed and Isuzu 5-speed are both factory Fiero five-speed manual transmissions, but they were used in different factory applications.
The Getrag 5-speed was used with the 2.8L V6.
The Isuzu 5-speed was used with the 2.5L four-cylinder engine.
Because both are five-speed manuals, the two are sometimes confused. Parts, cables, brackets, mounts, internal components, and service procedures should not be assumed to interchange without verification.
Relationship to the Muncie 4-speed
The Muncie 4-speed was used before the Getrag 5-speed became available in V6 applications.
The Getrag 5-speed added a fifth gear and became the later factory manual transmission for V6 Fieros.
Some owners prefer the Getrag for highway cruising because of its fifth gear, while some owners prefer certain four-speed versions for other reasons such as gearing, simplicity, or availability.
Relationship to engine swaps
The Getrag 5-speed is commonly considered one of the more desirable factory Fiero manual transmissions for engine swaps.
However, transmission choice for an engine swap depends on:
- Engine torque
- Intended driving style
- Gear ratios
- Highway rpm
- Strength
- Clutch compatibility
- Mounts
- Shift cables
- Axles
- Parts availability
The Getrag may be retained in some engine-swap cars, but high-output applications should be evaluated carefully.
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Strength and limitations
The Getrag 5-speed is generally suitable for stock V6 Fiero use when in good condition.
Its advantages include:
- Five forward gears
- Overdrive for highway driving
- Factory V6 application
- Good match for the 2.8L V6
- Desirable factory manual transmission option
- Better highway cruising than non-overdrive transmissions
Limitations include:
- Age-related wear in surviving units
- Possible shift-cable and clutch-hydraulic issues
- Parts availability concerns
- Not all five-speed Fiero parts interchange
- Must be identified correctly before ordering parts
- High-output swaps may exceed what is reasonable for a stock used transmission
Service notes
When working on the Getrag 5-speed:
- Verify that the car actually has a Getrag 5-speed before ordering parts.
- Do not assume Isuzu or Muncie 4-speed parts interchange.
- Check clutch hydraulics before condemning the transmission.
- Inspect shift cables and brackets.
- Use the correct fluid.
- Check mounts if there is drivetrain movement or clunking.
- Verify axle seal condition if fluid leaks are present.
- Verify transmission code and application when exact identification matters.
- Be cautious when using an original used transmission behind a high-output swap.
Identification
The Getrag 5-speed can be identified by transmission case features, shift cable arrangement, model year, engine application, RPO code, and related mounting hardware.
A Fiero Getrag 5-speed can often be identified by the location of the reverse-light switch and by the small dipstick on the aft side of the transaxle above the driver-side inboard CV joint.
Because many Fieros have been modified, repaired, or swapped over time, identification should be based on the actual installed transmission rather than the car's year or trim alone.
Useful identification checks include:
- RPO code MG2
- V6 application in later Fiero production
- Five-speed shift pattern
- Getrag-specific shift cable arrangement
- Reverse-light switch location
- Small transmission dipstick near the driver-side inboard CV joint
- Case features and mounting brackets
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