Tenaci Speedometer Ring 48 teeth This speed sensor tone ring fits the following two differentials: - Volvos original Automatic Locking Differential (Eaton G80) - Tenacis Torsen Differential for Volvo 940 & 740. Which also fits some late 240 models (88-90). The ring features 48 teethes and is made for differentials with aluminium covers. Only fits Tenaci differentials.  Installation guide: Put the ring around the Tenaci Torsen Diff, tap it with a hammer so it makes a round shape. Weld the ring together and then grind down the weld so that its clean and same level as the rest of the ring.