Wheel Hub Changes - Gen III vs. Gen II
| Subject: | Wheel Hub Changes - Gen III vs. Gen II |
| Models: | 2008 and Prior Cadillac Escalade Models |
| 2008 and Prior Chevrolet Avalanche, Silverado, Silverado Classic, Suburban, Tahoe |
| 2008 and Prior GMC Sierra, Sierra Classic, Yukon Models |
General Motors Vehicle Engineering has introduced a new design Gen III front wheel hub for the above listed vehicles which replaced the Gen II product.
These Gen II 4x2 and 4x4 applications that were previously serviced by seven part numbers are now serviced by three Gen III part numbers.
Concerns have been expressed by technicians regarding the use of the new supersessions and whether the Gen III hubs will properly fit the vehicles being serviced, especially because of visual and functional differences (splines). This bulletin has been developed to address those concerns.
Gen II Design | Superseded by Gen III Design | Applications Serviced | Model |
|---|---|---|---|
15225750 | 15946732 | Old Body Style HD SUV | 4X2 w/SRW |
15225751 | 15946732 | Old Body Style HD P/U | 4x2 w/SRW |
1522750 | 15946732 | New Body Style HD SUV, P/U | 4x4 w/SRW |
| |||
1522752 | 15946733 | Old Body Style HD P/U | 4x2 w/DRW |
15225753 | 15946733 | Old Body Style HD SUV, P/U | 4x4 w/DRW |
| |||
15881888 | 15910968 | New Body Style HD | 4x2 w/SRW |
15881889 | 15910968 | New Body Style HD | 4x2 and 4x4 w/SRW |
SRW = Single Rear Wheel DRW = Dual Rear Wheel | |||
When replacing an older Gen II design 4x2 hub with a new 4x2/4x4 common Gen III hub, it is acceptable to have a bearing with splines on it for a 4x2 application that previously did not. However, the older Gen II design 4x4 hubs should NOT be used on a 4x2 vehicle. The Gen II 4x4 hub relies on the tension of the wheel drive shaft joint to hold everything together. The roll form feature on the inboard side of the new 4x2/4x4 Gen III hub eliminates this concern.
The only hub that is not back serviceable is P/N 15719007 for 1999-2000 C25 applications due to a different hub flange to bearing flange offset.
Important: Only the new part numbers referenced in this bulletin are interchangeable between the 4x2 and 4x4 applications with the exception of P/N 15719007. Under no circumstances should any other 4x4 hub be used in a 4x2 application.
