GM 2500 HD Front Differential Pinion Yoke 697-154

This is Dorman 697-154, a cast iron front differential end (pinion) yoke for GM three-quarter and one-ton 4WD trucks. It replaces OE part numbers 15588336 and 88967027. The kit includes a new pinion seal and pinion nut.

Listed fitment: 1998-2000 Chevy and GMC K2500 and K3500, 1998-1999 K2500 Suburban, 2001-2015 Silverado 2500 HD, 1999-2004 and 2007 Silverado 2500, 2001-2006 Silverado 3500, 2007-2015 Silverado 3500 HD, 2007 Silverado 2500 HD and 3500 Classic, 2002-2006 Avalanche 2500, 2000-2013 Suburban 2500, and the matching GMC Sierra HD models. Dorman notes that on 2008-2015 trucks you should check the Service Parts Identification label in the glovebox for RPO code GT4 (3.73 ratio) or GT5 (4.10 ratio) before ordering.

Why it gets replaced: HD trucks that plow, tow or carry a heavy diesel up front put a lot of load through the front pinion. The seal wears a groove into the yoke neck and the front axle starts weeping gear oil, and a new seal on a grooved yoke will not stop it. Worn splines give a clunk when 4WD engages or when you change direction, and a damaged yoke causes vibration in 4WD.

On the bench: mark the driveshaft to the old yoke so it goes back in phase, pull the shaft, and check pinion rotating torque with an inch-pound torque wrench on the nut before anything comes apart. Hold the yoke with a flange holding tool, remove the nut, and pull the yoke with a puller rather than a hammer. Drive in the new pinion seal square, slide the new yoke on the splines, and tighten the new nut in small steps, checking rotating torque as you go until you are back at the original reading plus a few inch-pounds. If you overshoot, the crush sleeve has been over-compressed and needs to be replaced, so go slow. Refill the axle and check for leaks after a test drive.