In the last issue, we followed the complete disassembly of a used M20 Muncie four-speed manual transmission. After owner Brian Carson thoroughly washed all the major components and inspected the entire assembly for abnormal wear or areas of potential failure, he began the process of rebuilding it.
Armed with the same hand tools and equipment available during disassembly, without the occurrence of any unforeseen issues, and assuming the required equipment was on hand, the entire project took about a day to accomplish. Follow along as we complete our budget-build Muncie makeover and prepare this manual trans for thousands of miles of issue-free performance.
After visually inspecting...
After visually inspecting all the parts that would be reused for signs of excessive wear or fatigue, Brian Carson cuts a suitable length of 1 3/4-inch diameter steel pipe to help press Second gear, its bronze synchronizer block ring, and the First-and-Second gear synchronizer clutch assembly (synchronizer hub and sliding sleeve) onto the mainshaft. (Shifting keys are retained on the synchronizer hub with heavy bearing grease.) Then he installs the retaining springs.
Torque Specifications
- Bearing retainer nut, 40 lb-ft
- Input shaft retainer bolts, 20 lb-ft
- Side cover bolts, 18 lb-ft
- Upper tailshaft to main case bolts, 20 lb-ft
- Lower tailshaft to main case bolts, 30 lb-ft
- Filler plug, 30 lb-ft
- Speedometer gear retainer bolt, 4 lb-ft
Required Tools
- SAE wrench or socket set
- Various flat-blade screwdrivers or prybars
- Soft-face mallet
- Standard hammer
- Gasket scraper
- 3/16-inch diameter punch
- Hydraulic press
- A length of 13/4-inch diameter steel pipe
- A length of 15/8-inch diameter steel pipe
- 3/4-inch diameter steel dowel
- Bearing, race, and seal driver set
- Bearing separator tool
- Snap-ring pliers, external, notched tip
- Clutch-gear bearing retainer tool