Wayne Cook
April 1, 2009

When we bought our '67 Ranchero, we got a pleasant surprise when we discovered that the original C4 transmission had been replaced with an AOD four-speed automatic overdrive. The seller never mentioned the presence of the overdrive-equipped transmission and we listen with great satisfaction each time the transmission plunks into fourth gear at about 50 mph. The overdrive is great and the engine is just loafing as the car goes down the freeway. However, our Fairlane Ranchero is in reality a pickup as well. It has a bed and a trailer hitch. It is used for everything from pulling a boat to helping our friends move their refrigerators.

After having driven the Ranchero for some time, we've discovered that while the gearing is great for freeway cruising, the new final drive ratio of 0.67:1 makes the 3.00 axle gearing too tall for any kind of serious towing. Another argument for a deeper gearset is the fact that the Ranchero isn't exactly a rocket ship coming away from the traffic light with its original 289 4V engine, even without a load. These considerations combined with the howling noise emanating from the rear of the vehicle meant that it was time for a visit to San Diego Gear and Axle of El Cajon, California.

SD Gear and Axle is a complete rear axle service center for any Ford car, and we were able to make an appointment, drive our vehicle into the shop, and leave a few hours later with a completely refurbished and re-geared 8-inch differential. We didn't know what to expect when the gearcase was opened, but we were hoping that we wouldn't have to replace the entire third member. We felt fairly certain that we'd need to replace the ring-and-pinion, and the shop had a good set of used 3.50 gears available-just the ratio we had in mind. A locking differential, while considered a must for high-performance use, isn't as important when simply hauling a load or towing. Hence, we decided to avoid the added expense of a locking differential setup and retained the open rearend. Join us at San Diego Gear and Axle and we'll see just what is wrong with our third member and what it's going to take to repair it.

Cost: $272
Included used gears, new bearings and seals, lubricants, environmental fees and taxesLabor additional

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