Chevy Silverado and GMC Sierra 4x4 Questions

bruce48532 · December 2007

The transfer case actuator that engages the 4wd is working? You replaced the actuator on the front differental housing?
There are (2) actuators!

The blinking light should go from blinking to solid, I assume that is what is happening?

Did you reset the computer defalt after installing the new acturator? If not try that!
(3) quick on and off turns of the ignition switch, then start it.

conclutcha · December 2007

You Say Thair Is (2) Actuators. Where AreThay Located? I Only Found 1

vinceblas · December 2007

I have a 2005 Silverado 1500 ext. cab with 36500 miles and after adding on to my 7 inch lift with a 3 inch body lift and new Radflo shocks all the way around, I started getting phantom warning lights lighting up like a Christmas tree. My abs, brake, security system lights go off randomly and my radio shuts off and turns back on. I also get the service 4 wheel drive and service brake system intermittently as well.

Besides the 4wd Service light, has anyone experienced this and have a suggested fix? I've tried driving with an onboard computer to pull any DTC's but no I have had no luck, it says everything is working as expected and there is nothing to clear. I even tried unhooking the battery overnight hoping a truck ferry would come by and make all my troubles go away :P

As for the 4wd / AutoTrac I pulled the switch from the dash and did not see any cracks in the solder and hooked it up to a multimeter and all is good. Would it still be a good idea to buy the new switch? I hear the transfer case motor click but it does not engage and stays on 2wd. I am able to get it to go into auto and 4wd at times so I'm leaning towards the transfer case motor. Any other suggestions? I tried hitting it lightly with a hammer as possibly the motor could have been ceased. When it's in 4wd or auto it performs normally. I was going to go buy a new motor and replace it myself but if there are any other suggestions, i'd like to save myself the 533 bux and time doing it. GM keeps telling me it's a known issue and it's either the switch or the motor and quoted around 1500.00 for all the work and testing. WTF! And i'm now over 36000 miles and out of warranty. :mad:

If anyone has any suggestions, please let me know! Thanks!

bruce48532 · December 2007

One is located on the front differental housing, this is the easy one to replace. The second one is located the transfer case, (Transfer Case Encoder Motor) this one you must drop the front drive shaft to replace.

http://stores.channeladvisor.com/Auto-Parts-Direct-To-You/GMC/Sierra%201500%2c25- 00%2c3500/

bruce48532 · December 2007

One is located on the front differental housing, this is the easy one to replace. The second one is located the transfer case, (Transfer Case Encoder Motor) this one you must drop the front drive shaft to replace.

http://stores.channeladvisor.com/Auto-Parts-Direct-To-You/GMC/Sierra%201500%2c25- - 00%2c3500/

84rangerbfg · December 2007

i have a 2001 1500hd and my 4x4 doesn't work i checked my hub actuator and it works (also bought a new one) and when i put it in 4x4 low the transfer case works and puts it into 2 low but the front wheels aren't grabbing. any ideas? thanks :confuse:

conclutcha · January 2008

Thank You That Relly Helps So I Won't Spend So Much Mony Looking For Bad Parts

vinceblas · January 2008

I just got my truck out of the shop at Chevy and after 2 days of looking at it including the switch and transfer case motor, they found that the main ground for my truck had a bad connection and was loose. They cleaned the corrosion around the ground and tightened it and all my problems were solved. I was almost to the point of getting a new transfer case motor and switch after the recommendation from Chevy, but since I had other intermittent phantom lights also going off, they called in the electrical technician to take a look. They found 44 DTC's that stated "unable to contact..." and that's how they traced the ground. Once they fixed the ground issues, my 4wheel drive and auto trac engage within 2 seconds and doesn't switch from 2wd to 4wd and vise versa.

I was also over my miles and now out of warranty by 1200 miles (37,200) and was expecting to pay the 97.00/hr rate, but my service advisor talked to his manager and they covered it under warranty to troubleshoot and fix the root cause. GO LEE JOHNSON CHEVROLET, KIRKLAND WASHINGTON!!

bruce48532 · January 2008

I also have the problem of my dash warning lights going on randomly, not sure what the reason.
The dealer told me it was most likely a bad connector in the instrument panel cluster or bad cluster its self. Not much help, sorry!

Note - the last part I had replaced the (encoder motor) on the transfer case. I was told the transfer case was cracked near the selector shaft bearing. The bearing corroded causing the encoder motor to burn up.

vinceblas · January 2008

I would check the main ground to see if has any corrosion or is loose. I had 44 DTC's that showed which is nearly all my modules showing bad, but they were all phantom, including the service 4wd and service brakes, etc. The ground wire was cleaned of the corrosion and tightened. I don't know how it got loose, I suspect that it was due to the lift kit and then additional body lift, but unsure since they didn't touch that at all.

Here's my recent post on my fix:
I just got my truck out of the shop at Chevy and after 2 days of looking at it including the switch and transfer case motor, they found that the main ground for my truck had a bad connection and was loose. They cleaned the corrosion around the ground and tightened it and all my problems were solved. I was almost to the point of getting a new transfer case motor and switch after the recommendation from Chevy, but since I had other intermittent phantom lights also going off, they called in the electrical technician to take a look. They found 44 DTC's that stated "unable to contact..." and that's how they traced the ground. Once they fixed the ground issues, my 4wheel drive and auto trac engage within 2 seconds and doesn't switch from 2wd to 4wd and vise versa.

I was also over my miles and now out of warranty by 1200 miles (37,200) and was expecting to pay the 97.00/hr rate, but my service advisor talked to his manager and they covered it under warranty to troubleshoot and fix the root cause. GO LEE JOHNSON CHEVROLET, KIRKLAND WASHINGTON!!

KCRam · January 2008

Vince, be sure to give them props in the Dealer Ratings and Reviews section here at Edmunds!

kcram - Pickups Host

strodsfam · January 2008

I have a Chevy 2500 4x4 with push button 4x4 and Auto 4x4. The Truck shifts into 4x4 HI, Lo and Auto 4x4 fine. However 5-10 seconds later the 4x4 service light comes on. Also I cannot shift it out of 4x4 mode - pressing the 2w button has no effect regardless of if I am in Drive, Park or Neutral. However, If I turn off the truck and then turn it back on I can press the 2w button and it will go back into 2w mode just fine. This problem happens every time I try to go into any of the three 4w modes. The repeatability of it sounds like I'm doing something wrong. I should add that the truck has a 6" lift kit and 365/65R16 tires. It also has 74K miles.

I also have another problem with hard "clunk" shifting when the transmission is upshifting. It downshifts smooth. This only happens after the truck has run for 15 - 20 minutes. After turning off the truck for 10 minutes or so, like when getting gas, it will shift smooth as silk. Any ideas. Thanks for any help.

vinceblas · January 2008

Thanks kcram! I just submitted my review.

bruce48532 · January 2008

My guess the Transfer Case Encoder Motor is failing, sounds simular to the steps I recall to the failure of my 4wd.

The reason for the failure of the encoder motor on my 4wd was due to a bearing freezing on the sector shaft, this shaft connects to the encoder motor. The transfer case was cracked allowing water/salt to corrode the sector shaft bearing resulting in the encoder motor failure.

The transfer case crack... I don't think it was a crack from impact. I think it was a bad casting from the factory because of the location of the crack. JB weld in the crack fixed the problem along with a new sector shaft bearing and encoder motor.

link for encoder motor for your truck
http://stores.channeladvisor.com/Auto-Parts-Direct-To-You/Items/1420002-gmc%20c%- 20series?

dealer cost to fix this apx. $1200.00

strodsfam · January 2008

Bruce - Great information !! - Thanks very much. Do you need to pull the tranny to replace the transfer case encoder motor ? Thanks again for your information - Sal

ballz78 · January 2008

i have a 2003 sierra my prob is my 4hi and 4lo dont engage but my auto 4 does work. when puttin into 4 lo it does gear down but front wheels do not engage could this be the encoder motor on the transfer case. any suggestions would be greatly apreciated. I can hear it is tryin to engage when i push either the 4 hi or 4lo buttons but like i said the front wheels dont engage

strodsfam · January 2008

Bruce - Here's an update. Turned out the speed sensor on the front shaft was disconnected. We hooked it back up and all is well. Thanks again for your ideas.

osweeks · January 2008

My 4 wheel drive went out this past week without any warning.
I backed up to turn around and when I put it back into drive it made a grinding noise and the front wheels quit pulling.
I tried several times and it would never engage again just the grinding, like gears not fully meshed.
When I push the button it feels and acts like it engages 4hi and/or 4lo.
I've read most of the posts on here and most just say theirs just quit working and it's the actuator motor.
Is it possible that it is only partially engaging?
Could it be the autolocking hubs?
I haven't had time to check if the axles or drive line are turning, dark to work dark when I get home.
I just need some advice for when I start on it this weekend.
My truck has 172,000 on it and I've never had any other problems except fuel pump (twice).
Any help in the right direction would be a greatly appreciated.

Thanks
osweeks

bruce48532 · January 2008

thanks for the update!

bruce48532 · January 2008

for $80 apx the dealer should be able to tell you what the problem is from there you could fix it or have them do it.

Common 4wd problems

Speed sensor bad ( this is a recall on some trucks check with your dealer) - hard shifting, cluncking noise when shifting

Bad dash selector switch (bad solider or connector) - not lights lite on the selector switch.

Font axle actuator - No front wheel drive

Transfer case encoder motor - will not shift out of or go into 4hi or 4 low

my guess speed sensor or encoder motor

gavelar · January 2008

hey guys i got a 1999 1500,i started to drive the truck in 4x4 and the first 15 minutes i drove the car in 4x4 it was fine then there was clunk started in the front,i slowed down to about 5 mph and the clunk stoped.when driving in 2wd its fine but now im worried cause its snow season and i need 4wd.also it started when i made a turn if it makes a difference.

osweeks · January 2008

I found out what the grinding noise is. The splines in the front (4wd) diveshaft, where the 2 halves join, are slipping. I went to a couple of parts stores and they had never heard of that happening before. The shaft is $204 dollar with exchange, not that bad but, before I change it has anyone else heard of this happening? I would hate to change it if something else was the original problem and would just ruin another drivehaft. Any advise would be a big help.

Thanks,
osweeks

dmbaero · January 2008

Greetings Everyone! I am new to the group and looking for a little info regarding a recent problem with my truck. I have a 99 GMC Sierra 1500 Z71 with 195K. Recently while troubleshooting a drivetrain vibration I have found that the front driveshaft is not disengaging. The electronic 4WD works correctly and the front wheels disengage when switching to 2WD but the front driveshaft stays engaged and turning. Any suggestions of where or what to possibly look at as the culprit?

teresinski · January 2008

I have been having a problem with my 2001 GMC Sierra C3 for about 6 months now and am hoping someone can point me in the right direction to get it fixed. At low speed while making sharp turns I have vigorous shaking in what seems like the front. This truck is AWD all the time instead of push button 4WD. I initially thought it was a problem with my AWD, but a guy told me yesterday that it may have something to do with my transfercase. He suggested I drain it and put more fluid in. If the problem is not resolved after that I am to go take it in and have it reprogramed. Finally if this does not work I am to have some serious maintainence done. I am interested to see if any of you truck owners can point me in the right direction. I have had numerous work done over the last including a left ball joint and bearing and a UV joint replacement. I am hoping for a simple fix, but nothing seems to be simple or inexpensive with this truck. Please Help

mlarsen · January 2008

Recently took my 04 Silverado ext cab 1500 to the snow and heard this growling noise in the front end when turning. Also smelled a burnt rubber smell after I stopped. After going back to 2 Hi no problems. It is a manual 4WD transfer case switch.

Any thoughts

jackoue · January 2008

I ve seen numerous driveshafts strip the splines...usually due to lack of lubrication. I use to service loggers trucks in Northern B.C

gizzel0382 · January 2008

I have a 2000 gmc 1500 4x4. I took it to the snow this last weekend. I noticed when i got back it was making a noise. The only time it does it is when im backing up. I thought it might still be in 4 wheel drive but the front tires dont pull. I took out the front drive line but still makes the noise. It also feels like it dosnt have as much hores power. I dont have a hole lot of money to fix it. Is there some one who can help.

gizzel0382 · January 2008

I have a 2000 gmc 1500 4x4. I took it to the snow this last weekend. I noticed when i got back it was making a noise. The only time it does it is when im backing up. I thought it might still be in 4 wheel drive but the front tires dont pull. I took out the front drive line but still makes the noise. It also feels like it dosnt have as much horse power. I dont have a hole lot of money to fix it. Is there some one who can help.

bruce48532 · January 2008

It is possible your parking brake is locked on ?

bruce48532 · January 2008

thanks

gizzel0382 · January 2008

its sounds more like gears

soldiers47 · February 2008

I have a 1995 Chevy Cheyenne 1500 4x4 ExtCab 5speed standard, it has a manual floor shifter, when I put the shifter into high 4x4 it wont engage and no light, but when I put it into low 4x4 it engages but still no light comes on...this is frustrating..any answers would be greatly appreciated, thanks.

pillarll · February 2008

Hi I have the same problem I think. My splines look fine though on the two shafts. I have been through the entire front-end and cannot find anything else. May I ask how you discovered your problem and which part(s) you are planning on replacing? Is there any way the actuator is not engaging fully in your opinion? If you have already fixed your 4 wheel drive what was it? on my truck the sprocket that is moved by the actuator to join the shafts seems a little worn on one end. is yours like that? Thanks for any help! I'll let you know what we end up doing as well.
~Ben

grampy1 · February 2008

I have a 2004 GMC 1500 auto. trans. with 4wheel drive shifter on the hump. Manual says i can shift from 2 hi to 4 hi anytime below something like 45 mph.
More often than not when i have tried to do that i get a clashing of gears. Sometimes it shifts just fine,other time is doesn't. Shifting seems to be temp. related also.
I know the manual says i can shift while moving,but the clashing makes me nervous.
I have been stopping and shifting in and out of 4 wheel with no issues.
Am i overly concerned,or is my technique wrong. :confuse:
Thanks

rusty32 · February 2008

My truck will not shift into 4 low, the light flashes but will not engage. 4 hi and AWD work fine, anyone else had this problem?

quarque · February 2008

I've been reading at various sites about problems with GMC 4x4 performance in snow. Many people seem to be saying that no matter what they do they can't get decent traction. Most of this seems to be related to not having locking differentials at both ends of the truck. I know that none is offered for the front but a friend of mine said that the traction problems are considerably reduced when you have the locking rear AND the StabiliTrak option (with Traction Control). Is anyone able to confirm that their 4x4 truck with these options does well in snow and also those without BOTH of these options do NOT do well? I am considering a GMC for my retirement vehicle and it will see lots of snow in western Montana. I don't want to end up with a "2x3" as some have dubbed these poor perfomers because one front wheel gets no traction and brings the rig to a halt. Any other suggestions are welcome for a good snow truck. I notice that StabiliTrak is not available on the 2500 or 3500 for some reason(?). Thanks.

rustydwgtx · February 2008

I have the same model 1995 truck with auto transmission and manual transfer shift. When I shift the transfer into 4hi or 4lo the light on the transfer shifter does not come on, and the front wheels will not turn. The front drive shaft turns but no power to the front wheels.
Did you find out what the problem was with yours?
Anyone else know?

quarque · February 2008

sounds like your hubs are not engaging - are they manual or auto? if auto, it could be any of several things - some are vacuum operated, some are electric; check relays, fuses, wiring, etc.

rustydwgtx · February 2008

Thanks it is auto. There is a fitting on the front axle differntial that has two wires going to it. There is some dammage to the wires but they don't seem to be broken. I can't tell how the fitting is removed from the differntial if that is the problem.

happy0210 · March 2008

You probably already know this, try putting the tuck in neutral when you push the 4 low button. You can't be moving when you do it.

jasdav1 · March 2008

I have a 2000 chevrolet 1500 with the 5.3. It has the autotrac with pushbutton on the dash. Now for my problem, When I press the 4hi, Auto 4, or 4 low , the lights just blink and it will not go into 4 wheel drive. When I push 2hi the light comes right on. It will shift the transfer case into lo when I push the 4 lo button, but the front wheels do not engage and the light just blinks. I have replaced the switch and checked the ATC fuse and the 4x4 fuse. Any suggestions?

siregor · March 2008

I recently purchased a used 2005 Z-71. It has after market wheels and tires. The tires are 285/70-17. This truck is about 2" higher off the ground than most other trucks of similar vintage. I compared the original tires (265/70-17) diameter to the 285's and found that there is only about 1" difference. This would result in the vehicle being only 1/2" higher. Any thoughts as to why the difference in height?

Thanks

Egor

tpruitt · March 2008

yeah hi my problem I'm having is on my 94 k1500 the 4l or 4h is not locking in the drive shaft from the transfer case to the differential is turning but the front wheels are not locking or pulling and or the light for both to indicate it is on ,on the shifter is not on is this the differential bad or should I start some where simiple first any help please thank you

bruce48532 · March 2008

typically there are a number of components that may go bad.
1. selector switch, located inside the cab
2. differential actuator, located on the frt. diff
3. encoder motor, located on the transfer case
4. in your case vacuum module, location ?

bruce48532 · March 2008

consider this.... go to the dealer parts department ask them to pull up the parts on the comlputer part directory they think could be bad for that year 94. if they don't respond favorably ask if they could print out the exploded view of the part i have listed in the prior message. check them out one by one

tpruitt · March 2008

THANKS FOR YOUR REPLY I WILL TRY THIS AND LET YOU KNOW THE OUTCOME

country_boy · March 2008

I have a 00 Sierra 1500 ext cab. I am thinking to put a 3in body lift, add a leaf, and torsion keys. I would like to know if i would need aftermarket shocks and if so what would you recomend?

obyone · March 2008

Bilstein

kennydlate · June 2008

Truck driving in 2wd great...shifting hard though...(did this b4 switched from 2wd - 4wd back to 2wd..shifting back to normal)..tried it again...2wd - 4wd - 2wd..still shifting hard in 2wd...tried it again....2wd - 4wd not back to 2wd...I push the button nothing happens it doesnt even blink same as the auto button doesnt even blink like it is trying to switch...I have a 99 sierra z71 (new body style) that is stuck in 4x4hi...it will still switch from 4h - 4lo with no issues....with gas prices I dont need to be stuck in 4x4

jbeyhi · August 2008

I have had the same symptoms on my 1999 Silverado K2500 4x4 pickup. The first time it happened the dealer changed the actuator. I don't know what the part is and it worked but after 2 years the problem is back. So I am in search of what the actuator is and how to replace it. Could it be the switch that you referred to? Is the switch the push button panel? Any advise on your experience?

Chevy Silverado and GMC Sierra 4x4 Questions

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