4x4 Chevy 98 Blazer

I have owned this 1998 4x4 Chevy Blazer LT for about 6 months. I'ts in excellant condition with 77,000 miles. However about 3 times now it has put itself in 4 wheel drive LOW for no reason. Of course I normally drive in 2. The first time it scared me because it was in 4 low when I was backing out of parking and didn't know what was wrong because I didn't notice the light indicator had changed. The second time I was driving slow when it happened. The third time (yesterday) I was again leaving a parking space when I felt the change and again noticed it was in 4LOW. It's doing this all by itself! Why? It is the transmission?
Kat

Did you ever resolve this problem? Sounds identical to mine

No, I haven't recieved any comments. I just received your question today (July 22), and funny thing is I've had no problems since I first posted, then today I was backing out of a parking space and I felt the familiar "drag". I looked at the buttons and my Blazer had popped itself into 4x4 HI. Well, that was different, usually it's 4LO. Anyway, it's a simple matter of putting it in neutral and pushing the 2x2 button, but I just wish I knew what was making it do that. Otherwise the vehicle drives like a dream. I have no other problems at all. My Blazer has 71,000 miles on it. I bought it just last September, used of course. I am very happy with it. I have a warranty that will cover the tranny IF that's the problem but I hope it's something simpler.
Anyway, since it popped into 4 wheel drive again today by itself, I know it won't happen again for many many more days, UNTIL that is, the problem decides to worsen, IF it does. Imagine if I was driving down the freeway and it did that? Gads.
I'm going on vacation tomorrow, so won't be able to see any posts till August. Bye.

My feelings on this is it are. The only way for the truck to go into 4 LO is to be in neutral and not moving for at least 5 seconds. The 4WD computer has to see an input to shift into 4LO. If you are in gear it can't change it unless it thinks you are in neutral and it thinks you pushed the button.

I didn't know the trans must be in neutral to shift into 4 low. If that is the case then I have two problems as you stated. The computer believes the trans is in neutral and the the switch has been depressed. While driving along, the 4 low light will blink. At the next traffic light I am in 4 low without ever pushing the button or changing gears. Many times this has happened backing out of the driveway. In reverse I am in 2 WD. Then place trans in Drive and now in 4WD low. I took it to the dealer and they found no problems. They said next time it happens, have it towed. I really can't see how this will accomplish anything?

The hardest part of fixing a car or truck is making the problem happen. If we cannot get it to act up we cannot find the fault. Once we can get the problem to occur we can run tests to find the cause. But if the problem is not happening all the tests in the world will show its good. To fix this would be like throwing a dart anfd hoping that it hits the problem. Its not the right way to fix a car and it just makes you mader that we put a part on the car and its still not fixed. You have it on record with GM so if the truck goes out of warranty you can ask GM to cover the repair than and they should agree to do it free of charge.

Even though I didn't start this thread (I started my own), Thanks for your input Flatrater. When problems are sporadic, it can be extremely frustrating. I guess I question the competency of the work that was performed by my dealer. When I ask specific questions about components, I receive the answer "everything was checked and no problems were found". I agree that the issue is on record with GM however, it is a real pain to take it into the dealership and no changes were done to fix the problem. I would not be mad if they replaced parts that did not solve the problem. When nothing is replaced or repaired, I get frustrated because it probably will happen again and I will have to spend more time taking it to the dealership. Electronics and computers are great but I will never have a computer on my Chevelle. Troubleshooting is that much harder. Maybe I should try closing all the windows when the blazer does it again.:iceslolan

I have a problem that has just started with my 98 Blazer 4X4. While driving at freeway speeds in 2WD it appears that the car "shifts" into another gear. We hear a "whine" and it gets louder as you decrease speed to zero. Once you reach at or near zero speed a noticable "clunk" places the car back into a normal mode. You can then proceed as normal in 2WD. This has just began happening over the last 4 weeks. I first thougt it was a transmission issue but today when it happened at 70mph I slowed to 60 and hit the 4 high switch and the sound went away. I could then return the car to 2WD and proceed normally without coming to a stop. This happened several times in a 200 mi. drive today. Has anyone experienced this same thing?

Originally posted by chevelle
Even though I didn't start this thread (I started my own), Thanks for your input Flatrater. When problems are sporadic, it can be extremely frustrating. I guess I question the competency of the work that was performed by my dealer. When I ask specific questions about components, I receive the answer "everything was checked and no problems were found". I agree that the issue is on record with GM however, it is a real pain to take it into the dealership and no changes were done to fix the problem. I would not be mad if they replaced parts that did not solve the problem. When nothing is replaced or repaired, I get frustrated because it probably will happen again and I will have to spend more time taking it to the dealership. Electronics and computers are great but I will never have a computer on my Chevelle. Troubleshooting is that much harder. Maybe I should try closing all the windows when the blazer does it again.:iceslolan

Chevelle over the years of fixing GM's mistakes we are trained not to guess and throw parts on a car just to try. GM will not pay the dealer for guessing wrong under warranty, they will only pay for the part and labor that fixes the problem. So it is ingrained in us not to guess! Even when the car is out of warranty.

Just bought my wife a 98 Blazer, and it has the same problem of going into 4Lo by itself.. Anyone had any luck narrowing down the problem? Hate to just start changing out parts, module, harness, etc.

My 1998 Blazer is stuck in 4LO. No matter what I do, it does not go into 4HI or 2HI. In N, if I push the 2HI or 4HI, I hear a click and then 4LO light remains on. While driving or in park, the 2HI or 4HI will blink for about 30 seconds before turning off. All the while, the vehicle is still in 4LO. I replaced the actuator and that does not seem to be the problem. Not sure if anyone else has had this problem or the solution?

I have had similar problems with my 1996 Blazer. It will "shift" into 4LO on its own. It has done this three times. The first time I figured that I must have bumped it somehow, but the second and third time I was positive I didn't. Every time it has done it, however, I have been in reverse and turning hard to back up into my garage. (Yes, my baby has a garage :grinno: ) The dealership here swears that there is no way it can do it without being pushed, but I know for a fact that I was the only one in the truck and could not have touched it. Has anyone had any luck getting any help with this? Any thoughts are appreciated...

I have problems with that as well as my transmission, I was driving down a street and it went into a fast rpm's I right away noticed a problem. They I tried to go into reverse and the blazer did not respond, even in 4x4 mode it only goes forward. V/R Hugo HELP :o(

I have a 98 blazer 4x4 2 door as well. I just picked it up a month ago and have noticed it in 4 low 3 times when starting the vehicle. I'm worried its gonna go into 4 low driving down the highway and I'm in trouble. Did any of you guys resolve this problem? It should be a recall, seems like it could be dangerous. Please post if any of you have resolved this.

Somebody must have encountered --> resloved this issue, no?

One of my family members has a 2001 s-10 ZR2 and he had some simular problems as some of yours and he replaced the transfer box, which switches everything into gear, and now his works fine. Im not saying it will work with your guy's cars but i would give it a shot and if it doesnt work you can always take it back.

I have a problem that has just started with my 98 Blazer 4X4. While driving at freeway speeds in 2WD it appears that the car "shifts" into another gear. We hear a "whine" and it gets louder as you decrease speed to zero. Once you reach at or near zero speed a noticable "clunk" places the car back into a normal mode. You can then proceed as normal in 2WD. This has just began happening over the last 4 weeks. I first thougt it was a transmission issue but today when it happened at 70mph I slowed to 60 and hit the 4 high switch and the sound went away. I could then return the car to 2WD and proceed normally without coming to a stop. This happened several times in a 200 mi. drive today. Has anyone experienced this same thing?


I also have this problem, but the whine is a roar. It sounds as if an airplane is landing on my car! I took it to the dealership, but they can't duplicate the sound. It has happened 3 times since, but everytime I take it in, it stops. If anyone has any ideas on this one, please let me know, myself and the mechanics are stumped. They also need a reason to get into the transfer case (that's what they are guessing it is) so the warranty will take care of this. We put it on for codes, and nothing came up. THANKS!

I recently developed this roar - only noticeable on deceleration below 50km/h in 2WD. Pushing the 4HI button made it go away immediately but as soon as I went back to 2WD the roar came back.

I'm still not sure exactly where the noise comes from (front axle or T-case) but it seems to be that the front axle is engaged or trying to engage while the transfer case is in 2WD mode with the front drive shaft not driven.

After checking to make sure the transfer case itself switched between 2WD, 4HI and 4LO properly I then checked the actuator under the battery with a hand vacuum pump. With the front end jacked up I could spin the drive-shaft by hand and verify the axle was engaging and disengaging - worked fine. Then I measured the vacuum going to the actuator (engine running) and found 4inHg in both 2WD and 4WD modes - well that ain't right, in 2WD the vacuum hose to the actuator should be vented with no vacuum present. Then I crawled underneath and checked the vacuum harness going to the T-case for a blocked vent - found one open (the vent for 2WD mode not blocked), one had vacuum (4inHg) and the other connects to the actuator so no problems there. Finally I unscrewed the vacuum switch from the T-case (clean it first) and found that the button on the bottom was stuck in the body of the switch thus making the front axle think things were in 4WD all the time. Went down to the dealer and picked up a new vacuum switch ($54 CAN, ouch!) - going to put it in this afternoon but I'm pretty sure this will fix the problem.

Of course I only noticed this noise on the break-in drive right after finishing up a front brake job so I thought at first it was somehow brake related - thought maybe I'd left my caliper hanger wire in the ABS sensor ring or something!

My Jeep which has the same T-case has a slightly better front axle disconnect arrangement - it's still vacuum but is a push-pull not just a vent for disconnect and the 4WD indicator in the dash only comes on if the front axle actuator actually moves into 4WD position so if the switch failed on the Jeep I would see the 4WD indicator light even though the T-case shift lever was in 2HI. I really don't know why the Jimmy needs an electric T-case shift mechanism - just more expensive parts to go wrong.

Peter

My 1998 Blazer is stuck in 4LO. No matter what I do, it does not go into 4HI or 2HI. In N, if I push the 2HI or 4HI, I hear a click and then 4LO light remains on. While driving or in park, the 2HI or 4HI will blink for about 30 seconds before turning off. All the while, the vehicle is still in 4LO. I replaced the actuator and that does not seem to be the problem. Not sure if anyone else has had this problem or the solution?


You should try reseting the computer maybe that will work! I have a 2wd blazer but plenty of friends with 4x4 blazers and when something goes wrong that is what they do, if it does work disconnect the 4x4 control switch and see if it shifts in to 4lo then!

take it to the dealer, it is a recall issue. a sensor in the axle goes bad

This used to happen to me occasionally. I would come to a complete stopand try, sometimes I'd turn the vehicle off, then on and try again. Eventually it would shift back to 2hi. Hasn't happened lately though, becuz my 98' blazer got a new transmission at 100k. 15k later, it's yet 2 happen

My 1998 Blazer is stuck in 4LO. No matter what I do, it does not go into 4HI or 2HI. In N, if I push the 2HI or 4HI, I hear a click and then 4LO light remains on. While driving or in park, the 2HI or 4HI will blink for about 30 seconds before turning off. All the while, the vehicle is still in 4LO. I replaced the actuator and that does not seem to be the problem. Not sure if anyone else has had this problem or the solution?

I'm no expert but sounds to me like u need to put your truck into neutral and be goin 0-5 mph then hit 4hi or 2hi and then it will shift outa 4lo
Cause i know with my truck its 98 that if u hit the 4lo button with out bein in neutral the light just blinks then goes out agian and the same with shifting outa 4lo hit 2hi or 4hi the light just blinks and goes out unless your in neutral
It should be in your owners manuel how to shift into 4lo and out of it
hopefully u figured this out by now though

I have a problem that has just started with my 98 Blazer 4X4. While driving at freeway speeds in 2WD it appears that the car "shifts" into another gear. We hear a "whine" and it gets louder as you decrease speed to zero. Once you reach at or near zero speed a noticable "clunk" places the car back into a normal mode. You can then proceed as normal in 2WD. This has just began happening over the last 4 weeks. I first thougt it was a transmission issue but today when it happened at 70mph I slowed to 60 and hit the 4 high switch and the sound went away. I could then return the car to 2WD and proceed normally without coming to a stop. This happened several times in a 200 mi. drive today. Has anyone experienced this same thing?


Mine's doing the same thing... help... anyone....