The intermediate shaft on a GMC Sierra pickup truck connects the steering box on the frame to the steering column, which is mounted on the firewall and the dashboard. This intermediate shaft is collapsable, so that in the event of a front-end collision the driver doesn't get impaled on the steering column. Unfortunately, some years of GMC Sierra have a defect in the shaft, causing them to rattle and make noise. One solution is to grease the shaft, which keeps the noise down. Doing so takes a few minutes and basic tools.
Pop the hood. Locate the intermediate shaft, which is connected to the steering column on the firewall and has a black rubber boot around it.
Unbolt the pinch bolt on the top of the intermediate shaft with the 3/8-inch ratchet and socket and an open-end wrench, then unbolt the bottom of the shaft from the steering box with the 3/8-inch ratchet and socket. Pull the intermediate shaft out of the steering system.
Pull back the rubber boot on the intermediate shaft. Spray the grease into the shaft underneath the boot. Attempt to compress the shaft several times and listen for any noises or rattles.
Reinstall the intermediate shaft on the column and the steering box with the 3/8-inch ratchet and socket and an open-end wrench.
