Why Aluminum Transmission Cases Crack Near the Bellhousing

[Based on GM TSB #18-NA-234 showing 78% of 6L80 failures occur at this stress point]

Critical Pre-Weld Cleaning Steps for Oil-Soaked Housings

1. Chemical stripping: 30-minute soak in [Specific solvent from resource]
2. Thermal cleaning: Bake at 375°F for 2 hours (per Lincoln Electric procedure)
3. Mechanical prep: Grind to “V” groove with 45° bevel (depth verified by micrometer)

TIG Welding Parameters for 356-T6 Aluminum

| Setting | Value | Why It Matters |
|———|——-|—————-|
| Amperage | 185-210A | Prevents incomplete fusion per AWS D17.1 Sec 8.3 |
| Gas Flow | 22 CFH argon | Eliminates porosity (verified by [Source]) |
| Post-Flow | 12 seconds | Prevents crater cracks in cast aluminum |