Questions and answers from the Truck Trend Garage...
New Shocks for My Truck
Q: I tow a 12,000-pound fifth-wheel trailer with my 1999 F-250 Super Duty. How many towing miles should I get out of a set of shocks? How can I tell when I need new shocks? You can't push on the bumper to tell, as you can with a car.
A: On a lighter vehicle, you can push down on a fender or quarter-panel to observe the rebound of the suspension to help determine basic shock-absorber function. If the suspension freely bounces up and down a few times, the shock(s) are no longer damping suspension travel and are ready for replacement. It would require a really big guy to jounce the suspension of a 3/4-ton truck. So, the best choice is a careful visual inspection and a road test by a qualified technician. On the highway, you're looking for excessive sway on turns or a continued up-and-down bounce after passing over a dip in the road. Visually inspect each shock for leaks. There may be a darkened moist area near the sealed end of the shock. This is considered normal fluid evaporation and doesn't warrant replacement. A significant leak will produce a stream down the side and/or droplets hanging from the bottom. Also be sure all fastening bolts and nuts are secure, bushings are in good condition, and nothing is bent or damaged. This usually covers the bases, but you can take it a step further by unbolting one end of a shock and then manually expanding and contracting it. A good shock will produce a smooth, steady hydraulic resistance. However, this check doesn't apply to the Super Duty's gas-pressurized shocks. There's no shock replacement specified in the manufacturer's recommended maintenance schedules. However, if you have long-term plans for the vehicle, I'd suggest replacement when nearing the 100,000-mile mark. Also, there are a number of good aftermarket shock absorbers that may improve ride and handling from factory protocol.
Show Me Your Fittings
Q: I do all the maintenance on my 2001 Expedition. During oil changes, I can only find two grease fittings, both of which appear to be on the idler arm. Am I missing any other fittings on this vehicle? All other ball joints appear to be sealed.
A: Any ball joints or steering linkages (tie-rod ends, idler arm, pitman arm, etc.) that don't have grease fittings are factory-sealed units that don't require periodic lubrication. Carefully inspect each part to be sure there are no holes where a fitting may have broken or fallen off. Inspection of all suspension parts (sealed or not) is part of the manufacturer's maintenance schedule. In fact, you should have received a customer maintenance reminder letter from Ford focusing on, and including, an updated tie-rod inspection procedure. This type of notification is typically due to an issue with premature wear. Be sure that none of the rubber seals are punctured or are retaining water and that the inner and outer tie-rod ends show no signs of freeplay or corrosion. Each suspension and steering part is different. For instance, a tie-rod end should be replaced if any sign of freeplay is noted, but the idler arm will have a normal amount of freeplay that shouldn't exceed 5 mm. To accurately inspect ball-joint freeplay, support the suspension at a specified location to relieve spring tension. The maintenance reminder also recommends a visit to a Ford service department. If you haven't received a copy of the reminder, call Ford customer service at 866/436-7332. If you want to do the work yourself, buy an Expedition service manual.