Service Slants

Motor, Nov 2004 by Rosario, Tom

Ford Truck

Engine oil leak. Some 1998-2003 Econolines, 1999-2003 F-series Super Duty pickups and 2000-03 Excursions-all with the mammoth 7.3L Navistar diesel-may leak oil from the rear of the engine. On first glance, the leak may appear to be emanating from the rear main seal or oil pan gasket. In reality, though, it may he coming from the high-pressure oil pumps discharge fittings and/or end plug.

Ford says the confusion is because of the positioning of the drain plug machined into the crankcase valley, which allows any excess oil in the valley to run down the hack of the engine. A trace dye and a good UV or UV/Blue inspection lamp should help make the diagnosis a breeze.

If the leak is indeed coming from the high-pressure oil pump, installing three new-design O-rings that are part of a special service kit (Part No. 2C3Z-9G804-AA) should seal off the leaks at the fittings and/or end plug.

As you might imagine, getting to the pump on Econolines can be real tough. Begin by removing the intake air resonator and exhaust backpressure sensor, then remove the oil pumps reservoir. Next, open the drain valve on the fuel/water separator to release fuel pressure. Unless you want a mess on your hands, keep the valve open until the fuel and water completely drain from the separator. Once that's accomplished, disconnect the supply and return lines from the separator and the Lwu supply linus fur tlm sopainLur at the cylinder head. To complete the job, disconnect the electrical connector and fuel drain tube and cable, then remove the fuel/water separator from the vehicle. You now have a clear shot at the high-pressure pump. Getting to the oil pump on Super Duty pickups and Excursions is fairly straightforward, so lets move on to installing the O-rings.

There are actually two plugs in the high-pressure pump. Removing the wrong one could cause irreparable damage! The illustration above indicates which plug to remove. Now remove it, using a shop rag to soak up the residual oil as it continues to flow from the port. Remove the old O-ring from the end plug and toss it. Next, remove both high-pressure hoses from the discharge fittings on the pump, followed by the fittings themsulvus. Toss both O-rings fi'um the fittings, as well. Inside each fitting are a spring and check valve. Remove both using a tweezers or needle-nose pliers. Now clean the fitting and end plug ports using brake cleaner or a similar noncaustic solvent.

Once everything is nice and clean, reinstall the two springs and check valves into the discharge fitting ports, followed by two of the new O-rings on-to the fittings. Using the supplied sealant from the kit, coat the first three threads of the fittings, then install both into the pump, torquing them to 25 (Llbs. Reinstall the hoses to the fittings. Now install the remaining O-ring onto the end plug. Coat the plug threads with the sealant, install the plug into the pump housing and once again tighten to 25 ft.-lbs. To complete the fix, put whatever you removed back together, then top off the oil level, start the engine and check for leaks.

Chrysler

Transmission whine or vibration. Chrysler says that owners of some of its 2003 Town & Country, Caravan or Voyager minivans (build date on or before 1/19/03) may experience a vibration or whining sound from the transmission under light-to-moderate throttle conditions. The veteran people-mover maker says the condition is most obvious on a smooth road at vehicle speeds between 25 and 35 mph, and is most likely the result of the gearshift control cable rubbing against the transmission housing.

To diagnose either problem accurately, take the vehicle on the road and try to duplicate it under the speed and throttle conditions noted above. If you hear the whining noise or feel the vibration, take the van back to the shop, get it up in the air, disconnect the control cable and position it away from the transmission housing, then take to the road once again to see if the noise or vibration goes away. If it does, installing a new-design gearshift control cable that's part of a kit (Part No. 05127717AA) should remedy the situation permanently. Also included in the kit are mastic and complete installation instructions.

GM

Clunking noise during turning maneuvers. Owners of some 1997-2002 GM compact, midsize and fullsize cars (complete list below) may complain of a clunking noise during low-speed turning maneuvers. The problem can also manifest itself as a binding condition when the steering wheel is turned lock-to-lock with the car stationary. GM says that a sticking or binding intermediate steering shaft is the most likely cause of the trouble, and that lubing the shaft with grease from a special kit (Part No. 26098237) should eliminate the headaches.

To install the grease, begin by removing the intermediate shaft from the vehicle. Now extend the shaft fully by pulling both ends apart. Using the syringe included in the kit, dispense all of the grease into the aluminum end of the yoke opening. Next, install the rubber stop plug from the kit into the opening, then secure it by swinging the upper yoke 90° until one of its ears fully compresses the plug.