The Signs That the Universal Joints Are Going Bad on a 2004 Explorer

The universal joint on a 2004 Ford Explorer is a flexible joint used on the driveshaft. The driveshaft is the connection that transfers the engines power from the transmission to the differential. As the driveshaft spins, it also flexes with the movement of the rear axle. The universal joints on the driveshaft allow this flexibility.

Location of a Universal Joints

Theres one driveshaft in a rear wheel drive Explorer two if its a four-wheel drive. The rear driveshaft begins at the transmission where it has a splined slip joint that slides onto the transmission output shaft and is coupled to the driveshaft by a universal joint. Another universal joint is installed on the rear of the driveshaft, where it couples the driveshaft to a pinion flange.

Description of a Universal Joint

The universal joint is shaped like a plus sign and has four caps each cap covers a separate roller bearing. The universal joint is installed in the end of the driveshaft by means of holes made for this purpose. The universal joint is held in place by the bearing caps, which are pressed into place. The universal joints are available in either permanently greased style or equipped with grease fittings for ease of maintenance.

Worn Universal Joint Symptoms When Moving

Worn universal joints will be loose and make a low clunking noise when shifting into drive and from drive to reverse. However, the ring and pinion can cause the same sound as they wear, so further investigation is necessary to confirm that any suspicious noises are caused by the universal joints.

Worn universal joints will make a squeaking sound along with a clunking noise while moving at a slow speed. Lower the window and drive at 10 mph, while listening closely for an even and repetitive clunking noise or repetitive squeak as the driveshaft spins. This noise fades quickly as the speed increases.

Visual Inspection

Raise the vehicle and support it on jack stands. Look closely at the bottom of each bearing cap where it meets the body of the center of the universal joint. A reddish brown dust or discoloration is an indication of worn out needle bearings. This is also an indication that they have been run without grease.

Grab the driveshaft and the slip joint on the transmission end or the pinion flange on the differential end and twist the driveshaft and end in opposite directions. Push the driveshaft up and down and side to side looking for looseness in the joints. Watch the universal joint while taking this action and the play will be evident. It is not hard to find the freeplay, if the joints are worn badly. Replace the joints, if any evidence of wear is found.