The Chevy 12-bolt axle shaft (left) is tapered; the Ford 9-inch shaft is the same diameter throughout its length, except for the short section just after the spline end. This makes it easy to ...

These new nodular iron third member assemblies allowed for a complete redesign of the main part of the Ford 9-inch—the gear set. The custom third members had 4-inch side bearings for larger ...

However, the rest of the 9-inch family has been just as vulnerable to failure as any other differential out there primarily due to cast bearing ... of Ford 9-inch third members set up for 31 ...