I have a 99 Jimmy LS 4x4 with the 4.3 motor. The problem I am having is almost a rubbing noise that comes from my right front wheel well area. It tends to start after slowing down from highway speeds. I did discover that I can make it stop by puttingbit in 4hi and then back into 2hi. I can also make it start if I accelerate hard from under 30mph to above 50 and then ;etting off the gas. Once I change through 4hi back to 2hi, I can also tell there is less restriction on the truck. Any help would be appreciated.

 

Sounds like the front axle engagement collar is hanging up. I would inspect the cable that runs from the actuator under the battery to the front axle for binding. Also, with the truck running and transfer case in 2HI, pull the vacuum line from the actuator. If there is vacuum at the actuator when in 2HI, the vacuum switch on the transfer case is bad.

 

Is the info on where those are located in the Chilton? Just want make sure I can find what I'm looking for. I'm new to 4x4 and domestic. Was a tuner guy but I have been converted...

 

it sounds to me more like one of 3 things the axle tube bearing,cv axle or front hub it could also be in the brakes.

 

is the 99 jimmy the same as a 99 ls blazer? If it is where is the vacuum line at to check? i have the same exact thing in my blazer. i see the cable but no vac line. thanks, Clint

 

the vacuum line goes on from the bottom side of the vacuum actuator witch is probably under the battery box

 

I have vacuum coming out of the line that I unhooked from the actuator. Am I correct to assume that the switch on the transfer case is bad? thanks, Clint

 

it is more than likely the vacuum switch advance auto pats sell a Dorman help part# 49315 replacement swith for less than $20 I would give that a shot if that dont fix then it is more than likely the transfer case motor is failing and not locking back in 2 wheel drive.

 

The front end on my '97 makes a humming too.. not too bad though until 60-70mph when it gets really loud in the passenger compartment. I've been thinking that its a wheel bearing.

 

wheel bearings can normally be identified by test driving when noise accurs going around turns if it quits going to the left it is more than likely left wheel bearin and vise versa for the right if you jack it up and grab tire at 12 and 6 you might notice play in bearing but not always and if there is play make sure it's not ball joint play the humming could also be one of the inner cv axle joints or the front differential or 4x4 hanging up