I am having a problem with my 4 hi in a 99 model ls edition blazer. My problem is when i push the 4 hi button it engages but i can not run at 30 MPH on the road without it making a bad wining noise and constantly pulling to the right. It also makes a harder pull for the engine. I have had all the vacuum lines replaced along with the dash selector switch and motor on transfer case. The 4 lo in this thing works perfect though. Also when it is engaged into 4 hi to put it back into 2 hi you have to stop and reverse for a short distance at a sorta fast speed. Does any one have any ideals on what i can try next?

 

sounds like something is binding in the passanger side of your front axle. either your cv shaft or the axle carrier itself. I doubt it's 'fine' in 4lo, it's just because of the lower speeds/gearing you don't really notice it. my guess would be something in the axle carrier if you don't notice it in 2wd as the cv shafts still turn in 4wd.

My tip to you would be to leave it in 2wd, jack up the front end, put it on jackstands, turn the front driveshaft by hand and see if you can feal and weird binding in the front end, also try turing the right tire and feel for anything grabbing.

If possible, lock your front end, (pull the actuaror cord and hold it with vice grips or something in the locked position) then turn the front driveshaft and see if anything feels unusual. look up posi-loc for more information on manually locking your front end it.

the reason I say to do this rather then just shift it in 4wd and allow your vacuum pressure to lock it is to eliminate the rear end/transfer case from spinning narrowing it down to just your front end.


I could be way off on this, just an option Good luck

 

OK i have tried this out and couldnt find anything wrong with the axle housing or carrier. Another problem i forgot to mention was that when i am driving on a gravel road and when i come to a stop my right wheel locks up and the brake pedal makes a real loud noise and wont go down no more. Al pads are brand new this is also the same wheel that messes up during 4 HI. Could these two be linked too each other?

 

I would say it is a good possibility that the two are linked. You may have a more serious problem inside the front axle passenger side extension tube.

 

'94 Blazer 5.7L - Having similar problems. Did you find a solution? The right wheel locked leaving the driveway. Freed up in reverse and when I hit the brake it locked again. New brakes all around (calipers and hoses, rotors, drums) and flushed. Disabled ABS and still got it to lock. Got it up to about 30 MPH and slammed on the brake and let off it brought me to a stop. Noticed the CV Boot has a crack at the wheel and started to sling some grease. Going to replace that drive axle next. Any suggestions?