I have a 1989 Chevy 2500 4x4. I put it in 4 high and it feels like it is only engaging on one side of the front end. I still have some grip up front but the pickup pulls back and forth on the road.

SOURCE: 1993 Chevy 1500 pickup 4-wheel drive

I replaced the malfunctioning “thermal actuator” with the “Warn” Vacuum actuator setup, it’s been working great for about 7 years now, simple install, if I remember correctly, it was about $150.
That’s what engages the front diff into 4wd.

LAYNRAIL

• 18 Answers
• Posted on Jan 16, 2009

SOURCE: FRONT END VERY LOOSE HARD TO KEEP ON ROAD

They are also bad for the center link in the steering going south, as well as the idler arm.

SOURCE: 1998 Chevy S10 front axle will not engage when put into 4 wheel

Normal thing that happens as long as onone (worked) on it, is the vacume hose going to the engage sevevo under the battery box has fell of on either end or is brocken on the way there. Then the once or now leaky battery acid ate up this same servo. then the cable going to the front axel breaks sticks falls off or even someone needing one climbed under your truck while parked somewhere to get one to replace their brokeen one now you don't have one then theaxel engage arm or gearset is damaged

SOURCE: I have a 1990 K1500 4X4 Chevy pickup that wont

I had the same problem on my 90 K1500, it was the 4 wheel drive actuator unit itself. Bout it at the local parts store for 30 bucks and installed it in 10 minutes or less - and vavoom! 4 X 4 back in business.

SOURCE: 98 suburban LT 4x4

check the front axles,it sounds like they are binding up in a turn