tag1240sr

I need help! I have a 98 S10 Blazer 4x4. I am hearing a humming noise from the front end while in two wheel drive. If I slow down to 15-20 MPH then I hear a sound like 2 gears trying to engage each other. If I hit the four wheel drive button then the nosie goes away. I can then shift back into two wheel drive. This does this some times and am worried might cause more damage if I let it go.

I have replaced the Front Hubs, Upper and Lower Ball joints and many other things.

tag1240sr

Also there is no tranny codes in the system.

JimmyGold

May be the transfer case...

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MT-2500

You have a transfer case engagment problem.
Is it a Blazer or a s10?
The next question is what transfer case do you have?
If a 233 jump pin 13 to ground and read codes and post back codes.
MT

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Remember proper testing gives us the answer to many problems.
MT

mdrush

I also have a '98 4x4 and had the exact same issue...it sounds like the very common on '98s "partial engage" problem.....it won't throw a code though Change the actuator switch on top of the transaxle....it's a 10 minute job on the '98 and cost me 30 bucks from Carquest....didn't even use a jack.

Coming from the front drivers side reach on top of the transaxle and remove the clip with the 3 port vacuum connector....use a 7/8 wrench to remove the "switch/plug" (it comes out real easy)...install the new switch and reconnect the connector.....just be careful not to let crud into the hole when you install the new actuator.

If you look at the old switch I'll bet the ball is stuck halfway.

There's also anothe actuator on the passenger side front axle that I changed...that switch had a two line connector. While mine wasn't stuck I replaced it anyways as it was the original (only 15 bucks).

All told it was 45 bucks and 15 minutes of work...4WD works great now.


Mike

MT-2500

To jump pin 13

http://www.troublecodes.net/OBD2/

__________________
Remember proper testing gives us the answer to many problems.
MT