However, there are some clues that might suggest the presence of Positraction, particularly on older Plymouths:
* No visible external differential cover bolts: Early versions of Positraction used a sealed housing that lacked the typical external bolts seen on open differentials. This is probably the best external visual cue, but many were later modified.
* Casting marks and numbers: The differential housing itself might have casting numbers or marks that indicate it's a Positraction unit. These would need to be cross-referenced with Plymouth parts manuals or identification guides specific to the year and model of the car.
* Specific identification tag: Some Plymouths had an identification tag on the differential itself that specified the type of rear end.
In short, you can't reliably identify a Positraction rear end by looking at it alone. You'd need to inspect internal components, check for casting numbers, or confirm through documentation or a vehicle history report. The key characteristic of Positraction is its limited-slip action – the ability to transfer power to both wheels even if one loses traction. This isn't something you see externally.
