I’ve got a 1999 Yukon with a new (rebuilt) engine ad a new (rebuilt) tranny, both only about 3-4 years old. Within the last 2 years it has started to ‘snap’ to the left or right when I move the wheel just slightly. My husband tightened the steering and that helped a little but it still does it. It’s pretty scary when your on the highway and go to adjust your lane placement and the wheel jerks out of your hand in the direction you’re turning! Also, the truck has also developed a nasty habit it simply shutting down while I’m driving. The last time it did it I was on the freeway doing 65! It always starts right back up but I’m worried that one of these days it won’t and I’ll find myself in a real pickle! Both of these scare me to death! Does anyone have any ideas? Nobody I’ve talked to (including mechanics!!!) seem to know what these problems are.
2WD or 4WD?
The steering problem is likely in the rack assembly, perhaps in the spool valve or even perhaps a sticky piston in the rack itself. The way the system works is that fluid is circulated by the pump, and when you turn the spool valve directs the fluid to the appropriate side off the piston inside the rack assembly. The fluid then pressurizes and helps move the rack. If something is preventing this from happening smoothly, it could stick then jump when the steering fluid pressure overcomes the friction.
However, it could also be in the steering link ends where it ties to the steering knuckle or in the ball joints. Either of these could stick if bad.
Check the latter out first. If you have a bad link or a bad balljoint it could be extremely dangerous. It could suddenly let go.
The engine shutting down is a different problem. When was the last tuneup? Is this '99 engine distributor based? Are there any other symptoms?
Generally, sudden shutdowns that allow immediate restarts are losses of spark. Often they’re tracable to neglected maintenance.