4 wheel drive not working

Hello, I'm Danny.

It sounds like you might be having an issue with the front differential actuator. It's actually a common problem in these obs (old body style)trucks. I've attached picture steps below with location and instructions. Hope this helps and thanks for using 2CarPros.

Good morning, thanks for your help. i replaced the actuator this morning, but it still does not work. 4 wheel instrument lights go on then off and stay off.cannot be switched. Locked in 4 wheel. Thanks

Hello again.

Quick question then.... Were you receiving a diagnostic code regarding C0550 or U1026 when this symptom started? Let me know and we'll go from there.Thanks again for using 2CarPros.

Danny-

Thanks For the help I decided to change the transfer case shift motor and everything is working perfect. Thanks again

Awesome!
Glad you got the problem solved... Please use us again in the future for any other automotive questions. Happy Holidays and thanks again for using 2CarPros.

Danny-

I have a 8 cylinder 7.4L suburban. A friend had vehicle in drive but not moving and engaged 4wd. What kinds of problems could result from doing this? The shop said I needed rear axle housing 3/4 ton w/9.5" ring gear, transmission, and a transfer case to be replaced with used parts. I am wondering what could have occurred by just pressing the 4wd button while the vehicle was not moving but in drive. Please let me know if this sounds right.

It'll probably be fix when they replace the transfer and transmission-

Is it possible to cause those types of damage just by attempting to engage 4wd while in drive at a standstill?

Could be a problem with the transfer case switch

would the transfer case switch being bad cause damages to the rear axle housing ring gear and transmission?

No it won't, just for the 2wd/4wd engagement

Drive Train Axles Bearings problem
1998 Chevy Suburban V8 Four Wheel Drive Automatic 200k+ miles

When put in 4wD we get a lot of clunking from the front end. Could this be the Transfer case actuator not engaging completely?

It could be the actuator. Can you tell if the sound is coming from the transfercase area or the front axle area. If it is the axle, chances are the problem is there and not the actuator.

I think it is coming from the front axle, almost seem like the passenger side but hard to tell. Feels like someone is smacking the axle or hubs with a 5 lb mallet. Are the locking (automatic) hubs in this vehicle something that can be disassembled and lubed? I had an Isuzu Trooper II w/semi-auto hubs that had to be disassembled and lubed with ATF once a year or they would keep popping out and dis-engaging as you traveled down the road... I was going to price a new solenoid but I hate the shotgun approach. I had a GMC Sierra p/u that had a solenoid that mounted on the front axle assy, this one appears to be on the side of the transfer, right? My ALLDATADIY account does not show good breakdowns of the 4Wd system...

Thanks again...

Please note that this is a1999 NOT a 1998 as originally posted. My apologies.

1997 Chev suburban won't go into 4 wheel drive. I have replaced actuator and transfer case switch, but it still won't work. I do have power at both actuator and switch, and the fuse is fine. What do I try next?

Remove the actuator and see if it will work out of the transfercase. If you have power to it, either something in the transfer case is bad or the actuator is on a bind of some sort when you install it.

Let me know what you find.
joe

Okay, will try that in the morning. What about the front axle engagement switch? Know anything about that? All three wires going into it are frayed. I took it out, and checked for power, and it does receive power when I place the 'burb into 4 wheel drive.

Seems to be a rare part, but have found a couple of places online that have it.

That could be the issue too. Even if the transfer case is shifting properly, if the axle doesn't engage, you won't have 4wd. Are you getting 12v to it?

My 4 wheel drive on my 1997 chevy suburban will not engage the light flashes but it doesn't engage at all. What is the problem and how can I fix it myself. Thank you.

Hi:
Check to see i you are getting power to the actuator mounted to the transfer case. If you are and it won't switch, the actuator is bad.

joe

I have a 1996 Chevy Suburban K2500 7.4L 454 4X4 with 217000 miles. Originally, driving the truck to about 40 mph would appear to slip into neutral, while the speedometer kept climbing. Stepping on the gas made the speedo go faster, but the truck did not. Once you slowed down to about 20mph, it would make a very disturbing sound like it was slamming back into gear, and you could accelerate again. At first, you could engage 4WD and it would drive up to 70mph without slipping at all. It has deteriorated to a point that driving in 4WD does the same thing now. I didn't think it was the transmission, because it drove fine in 4WD for a long time, so I suspected the transfer case. I have inspected the transfer case, and the chain and gears seem to be in good condition. I was told it could be the TCCM or the transfer case mode fork or pads. The pads are a little worn and chipped, but is that sufficient wear to cause it to act like this? What is the function of the TCCM in this process? Where is the TCCM located? I was told in the door panel, and under the steering column, but haven't really located it yet.
What further steps can I take to troubleshoot this effectively?

your TCCM is under the dash on steering column bracket. your speed sensor is on teh tcase so if it sppedsup and you don't go faster it may be teh trans screwing up as there is a speed sensor on the input shaft as well. the slamming in and out may be one of the clutches inside the trans going in and out either from an electrical problem or failure. it also could be the tcase slamming in and out due to the trans. the TCCM is more for shifting in and out of 2wd/4wd. we can't see how worn the pads are but if this is original you do have high mileage on it. I really think you should go to a trans shop so the guy there can scan it and give you a better perspective of this. the only other thing i can think of is that it doesn't engage the tcase correctly. but i wouldhave the trans checked first.

Originally, the problem was ONLY in 2 wheel drive. I drove a thousand miles in 4WD without a problem ever. I was able to pull a 30ft. trailer in 4WD for 80 miles at 60mph without the trans slipping once. Only until recently, does it do it in 4WD. Is it at all possible the transfer case is slipping into neutral? It has a shifter on the floor, not push button shift. 4WD low seems to be OK still.

I think you have a new venture 243 t case. IF you get an intermittent grinding noise then check the shift linkage for binding and if that's ok, remove the rear output housing and check for a broken snap ringon the rear bearing. again i don't know how worn your pads/forks are so i can't comment on that. but if it doesn't go into gear all the way then you could also have a bent shift fork or rod.

Its a 241 C transfer case, and the mode fork and rod look fine. I want to think that putting it in 4WD affected the tranny in a way that it didn't slip at first, but has finally caught up with the 2WD problem. I would have a warm fuzzy feeling if I knew the tranny would act differently in 2WD then in 4WD. I believe I have a 4L80E tranny, and I would like to know if there would be a better choice for a tranny that might give me better mileage, since I don't really need the 10,000 lb towing capacity anymore. I read a Bowtie Overdrive 700R4 might be suitable.

the 4l80e is a lot better trans than teh 700r 4. it's an electronic version and has way fewer problems. not much you can do about fuel mileage with a 454.

My '93 chevy suburban 4 wheel drive aint working. it just stopped working one day while engaged in 4 wheel drive. It has been working just fine then all a sudden it stopped. this happen before then it decided working again. We checked the fuses there fine, the floor shifter works fine, but it just wont engage. Solutions?

Hi:
Does you vehicle have an electric or manual (lever on the floor) 4x4 engaugement?

Its automatic with the shifter on the floor

Transmission problem
1990 Chevy Suburban V8 Four Wheel Drive Automatic
----------------------------------------------------------------
When I engage the 4x4 it seems to be binding up before the wheels can even make 1 rotation.It's almost immediately.The truck has a 6" lift but worked fine before.I put a front driveshaft spacer in today but the problems still exist.

are front and rear gear ratios the same? are all 4 tires the same size?

I did have the rear-end replaced by a mechanic.He said it was the same 342 gear ratio.I guess I need to climb back under and take a look at the stamp on diff.

THATS THE ONLY THING THAT WILL MAKE IT BIND. look at the numbers on the ring gear. it will say like 11.41 =3.73 etc divide first number into second number