Abstract: A roller bearing for use in transmission cases (1) made from aluminum alloy or other lightweight materials where the transmission contains a steel shaft (2) which is supported in the case on two directly mounted tapered roller bearings (8,9) so that the two bearings (8,9) confine the shaft (2) both radially and axially. To compensate for the differences in expansion and contraction between the case and the steel shaft (2) as the transmission or transaxle experiences variations in temperature, a race (20) of at least one of the bearings is fitted with a compensating ring (34) having a coefficient of thermal expansion greater than that of the case (1) or shaft (2). As a consequence, the bearings operate at a generally uniform setting over a wide range of temperature variations.