I made the same post with no reply. My back wheels spin, but no front wheels. No problems switching - no blinking lights on the panel. I can hear the transfer case switching. Just no frot wheels. Also replaced the cable , actuator, and swith from the transmission, but no 4wd.
I have been thoroughly reading these question and answers but iv yet seen the problem that im experiencing. It seems like these jimmys have a lot of components that the 4x4 requires, to function properly. But here is the question to all experienced. FYI--I own 96 gmc jimmy 4door 4.3vortec.--- As i drive in 2wd it performs fine until speeds over 50mph or when i hit a bump or pothole, sometimes im forced to because NJ roads are terrible. What happens is i hear a loud grinding, roaring noise coming from seems like the from driver side axle somewhere. Its not a wheel bearing. It doesn't happen all the time seems when the front wheel is moving back and forth in positions it creates a grind noise from that side. Now as i hear the noise i slightly slow down by releasing the gas and it stops than i coast, without much gas and brake stop and go action, to prevent much of movement because then the noise will happen again. I know that was a lot. But here is the main point. That accures in 2wd now when i engage into 4wd hi i hear it engage but NO 4x4 and seems like that noice is stopped. I kinda tested it and seemed not to make that noise while im "in 4wd hi and the light is lite. but NO 4x4. The 4wd LO works FINE. As i read in previous replys im now stearing to believe that it could be that coupler in the pass axel??. Like i said, i hear the 4x4 engage into 4wd hi but front wheels dont turn i never checked the front drivetrain just to confirm it was spining but seems like its something else. All help is appreciated. I know theres some talent out there to help another jimmy guy out. Thanks everyone.
i recently replaced the engine, spark plugs, fuel pump, and temperature sensor and i got the fuel pump replaced one day and the next day the car stops on the highway and i had the guy who fixed it check the car and he said the fuel pump is running and 2 other people have told me the same. and the car cranks sometimes and goes back out and right now the battery is dead and my key is stuck could someone please give me some advice
we know what the discussion is but if someone needs a hand, help out and be curtious. As for your the problem,, i now have 2 gmc's that are really wierd with electrical probs but jumping battery to get key out, disconnecting it for about an hour or turning key back off then on seem to keep me rolling, make sure everything is off when leaving vehicle for the night, good luck!
I have a 2000 GMC Jimmy with 2hi, 4hi, and 4lo buttons on the dash. It seems to switch between them all properly and when put in 4lo it sounds like it has properly went into 4lo, 4hi is the same. It is snowy and icy here and it didnt seem to be getting around like it should considering i about got stuck in my yard in 4lo. So my wife and I watched the tires while in 4hi and 4lo to see if all wheels were turning, but only the back two were, and sometimes only the back right tire would spin.
Okay . . . . I've done some research on S10 forums and I think I've got an answer for this one.
When your hub lock out switch fails, it can fail in the vacuumed position. This causes the front differential to be engaged which commonly breaks the thrust washer. I found the information on s10extremist.org in their technical articles link. Lots of great info there - even the instructions to fix it.
Further research, and not sure if this is as big a deal in the US as in Canada, but if you're replacing the hub lock-out switch on the transfer case the transmission experts recommend buying the part from a GM dealer - apparently the aftermarket parts in this case aren't that great. I had an aftermarket one break immediately (and I'd let my 2 yr old play with the receipt).
And lastly, if anyone can find a vacuum hose routing diagram that would be very helpful.
I had this problem with my jimmy> when I pushed the four high button it would just click and blink than go back to two wheel. When I put it in 4 low I would hear the transfer case switch and it would drive like it was in 4 low but no power to fron wheels. The problem I had was a bad vacume line. under the hood on the driverse side behind the throttle body follw the vacume line towards the vacume pump on the fire wall than down to the tranfer case and make sure it not cracked or like mine collapsed. Could also be a bad vacume acuator under the battery. hope this helps.
2001 GMC Jimmy 4wd - My problem is that when I am driving, for no reason at all the Jimmy will drop from 2wd to 4wd. My mechanic cannot find any reason this is happening. He had it for two days (and yes, I do trust him) and could not figure out why it does this. HELP!
I have a 2000 GMC Jimmy, 4.3, 3 buttons on the dash (2hi, 4hi, 4lo). Just changed the transfer case becuase bearing was out in old one. Now, when engaged in 4 wheel hi, can't get any power, studders while gaining speed, feels like I'm driving with the brake on, and makes a whining noise. Tried to engage back to 2 wheel, hear the transfer case motor, but wouldn't engage for about 2 miles. What is the problem????
Ok so here's my story. I have a 96 GMC Jimmy that is having issues. My mechanic has had my truck over 2 months now. He can NOT figure out what is wrong with the battery. It will not hold charge. Something is draining it severely. Pardon if my spelling is off. If you have any kind of opinions I need any kind of lead I can suggest to him to check. Please and thank you.
My problem was the encoder motor on the transfer case some times it would work sometimes not. I got it fixed now works fine Last winter was a breeze. 4 wheel worked fine
I bought a 98 GMC Jimmy SLS, 2 door, 4x4. When I got it it was in 2 hi, wouldn't go into 4 hi, but would lock and then unlock immediately in 4 low. Got it into 4 hi, now it's stuck. When you push the buttons for 2 hi or 4 lo, the light flashes on the button and the TCCM clicks 5 times, but nothing happens. After trying this a few times the light only flashes once quick and the TCCM clicks once. It goes back to a few flashes if you unplug the battery and wait a few minutes, but still no shifting. Brought it to Mr. Transmission, they told me it's the encoder motor, so I replaced it, no change though. Changed the TCCM too, no change. What else could possibly be wrong?
Summary: stuck in 4 high, changed encoder motor, changed tccm, still wont shift out of 4 hi. TCCM clicks, and light flashes on button, but goes to only one click and flash after trying it a few times.
only a few more things to check. One is the vacume acuator under the battery, One is the vacume switch on your transfer case. And another is the switch on the front differential, I had a bad shift cable also on mine. Like I said its a lot of trouble trying to find out whats wrong. And yes don't forget the push button switch on your dash. I changed that too. About thirty dollars. but i didn't need it. Hope this will help
I just bought a 1999 Jimmy and Im not sure how the 4 wheel drive works. I hit the 4 wheel drive button and it just flashes. The first time I did it I heard a clanging sound in and out of 4 wheel drive. Even though the light flashes it seems to work in 4 wheel drive. When I drive it in a circle I can feel the tires fight each other. I dont have a clue what is suppose to happen. Is the light suppose to stay on or is flashing ok. I guess I need some tutoring on what to expect as far as the lights go. It only has 75k miles on it but undercarriage is rusty like from sitting a long time. I have the 4.3 vortech and only gets 14 mpg. Is it possible it stays in 4 wheel drive?
Lesss then a year ago I replaced both of the hub bearings on my Jimmy. Now it is starting to make the same noise it was making before. Can someone offer me a solution so I do not continue to put money on the same problem.
Push that truck off a cliff, I think GM jimmy was a test truck so GM could maintain continuous revenue from service charges..., I loved that small truck when it worked , once it falls apart there is no stopping to it...., here in Canada fuel pump replacement costed me $1300 lol after 1 year again the fuel gage failed after a year !!!! the fuel gage reader is in the fuel pump in the tank lol..., I need another $1300 to make my fuel gage work LOL !!!! now the truck rests off of the west coast in the ocean... I hope I never see that dancing fuel gage display ever again !!!!
Engaged in 4H or 4L lights are solid and the front drive line turns. Cable is pulling with vacuum but no power to the front wheels. I removed the cable at the axle tried to get anything to engage buy pulling the coupler by hand in gear and in 4wd on jack stands with no luck. The shaft only moves about 1/2 inch. Wondering if that is enough to engage the coupler. Also, I would think that you would have vacuum in 4wd but none in 2wd. I have vacuum to the cable in both. Since I have vacuum in both 2 and 4wd, I wonder if it has been engaged for some time and has damaged something in the front diff. If this is not normal, what controls the vacuum coming from the transfer case?
Took the front diff apart and found a striped connetor gear. There was a broken shim that was blocking the slip gear. This kept the slip gear from engaging completly and stripped one edge of the connector gear. I am still wondering what blocks the vacuum when switched to 2wd.
I have a 1997 jimmy 4x4 won't engage, front axle does not lock. Thanks to this forum I have found several problems and fixed them. The vac. switch was stuck. I replaced it. The actuator was torn. I replaced it. The dash switch seems to be working fine because the TC does shift and the front driveshaft turns. It also shifts into 4lo. I have removed the vac. switch and pushed the ball up by hand and I get vac. at the actuator hose. I installed a vac. gauge in the actuator hose and observed that when the 4hi button is pushed there is a verry quick jump of the needle to about 4" then it immediately drops to zero again. This occurs whether or not the vehicle is in motion. If I then shift into 4lo nothing happens on the vac. gauge. However, when I shift back to 4hi the vac.reading is 1.5", and stays there until I shift into 2hi. I'm thinking that there is an internal TC problem that is causing the switch to remain down. Has anyone had this problem. Also what does the electric switch on the front differential do. I haven't checked it yet, will do so tomorrow. Thanks for your help.
Hello revn57, I'm not sure but I think that the vacuum is blocked by the switch on the transfer case and is vented off of the actuator by the same switch . That's what the third hose is for. It is the vent. One hose goes to the engine to supply vacuum. One goes to the actuator to operate the cable. one just goes to the atmosphere to allow the actuator to release vacuum through it.
I checked the front axle switch, it seems ok. although there is 12 volts at the switch conector. I was expecting 5 volts... I took the new vacuum switch out of the transfer case again and pushed the ball in by hand and rotated the front drive shaft with the engine running and the front wheels turned, so the actuater, cable and axle are ok. I removed the transfer case shift motor and shifted the shaft by hand. The part that pushes the switch up moved as I turned the shaft. I then installed the vacuum switch with the case in 4lo and turned the front driveshaft by hand with the engine running. The front wheels did not turn. My conclusion is that the new switch is defective or wrong. I will get annother switch tomorrow this time from the GMC dealer.
I fixed mine by changing the encoder motor on the transfer case. It sounded like it was going in but it didnt work sometimes, Hope you get yours fixed soon four wheel drive season is upon us
I was right. The new switch that I put in saturday was either defective or wrong. I just put in a new OEM switch and the 4wd works perfectly now. Apparently there are two different transfer cases mine is a 233-c I don't know the number of the other case. The part no. for the OEM switch is 89059420 . I will return the defective switch tomorrow for a refund. I hope that my experience with this has helped someone. Lesson learned, use high quality parts the first time. I don't know if the two different cases use two different switches or not, I'll find out tomorrow.
Well the actuator has failed again because of trans fluid getting in it . I guess I should have blown out the lines the first time. However I have found a manual cable shift kit for the front axle. I will install this manual shifter cable soon. the kit is available at Summit. costs about $160.
I recently had some tires swapped over from winter to summer and upon getting a front end alignment I was told 2 bolts were rounded. One on each side and one front and one rear. Is this a hadr fix? Sould I just change the nuts rounded or just change all 4 bolts. How hard is it and what do I need. Thanks Mike
The auto 4wd, the 4wd hi and the 4wd lo lights just blink until 2wd button is pushed. The drive shaft from the transfer case turns but the front differential wont engage. Have checked fuses and replaced actuator. The battery was disconnected for a good 45 mins while I played around with the actuator. The fluid level in the differential is good. Have tried to trace the vacuum line but I keep getting lost.
I have had the same problem. I just had both front wheel hubs replaced at 107K miles for $750. I had to have mine replaced because to anti-lock brake sensor failed in the left hub and the right one was noisy. I don't think there is a solution for this problems. Just like there seems to be no solution for leaking intake manifold gaskets or the flaky fuel gauges or the failing fuel pump. The is a nice "little" SUV, when it runs!
I stumbled on to this site and found it to very informational. But have searched and searched and have not found the answer I'm looking for. While in 4hi, driving up a very steep hill (it performs better) the vehicle is fine. But when I turn the corner, it hesitates as if it's struggling about to cut off or something. Another time I forgot to disengage 4hi, I tried backing into a parking spot and the same hesitation occurs. Is my jimmy sick or just too old. Feel free to be brutally honest. Mind you I just purchased jimmy 6wks ago. Trip to the folks I bought it from is planned tomorrow.
Sounds like you need a tune up. But when in 4 wheel drive all axles are turning and make it difficult to steer. Try taking it out of four hi when you are parking or backing up. Just hard to get used to four wheel drive. It really makes a difference if the road is snow covered or not when steering. Hope this helps. When its hard to steer that means your front wheels are engaged.
My friend when transmission fluid is getting into your vacum acuator motor next to the batter case its because you need a new seal between your transfer case and transmissio I blew out two or three acuators before i got it fixed. Hope this helps
Usually with front hubs I found that the more expensive hubs are worth it I changed four or five hubs out before I found out that the cheaper ones didn't last more than a year or two. Salt and dirt mess up the sensors. Hope this helps
I know this is an old topic but I think I may find some help with my 2000 gmc sierra 1500. My lights act normal but the only 4wd mode that locks the front wheels is auto. All the signs of 4wd working r there except the front wheel spin. The gear ratio is dropped in low the think when its initiated the whole nine. But the only way they pull is in auto
My 1997 GMC won't engage 4wd. The transfer case will engage low gear, the lights on the dash switch light up (2wd is burned out but 4lo and 4hi will light and stay constant when pressed). The front drive shaft definitely turns. There is vacuum at the acutator, and the cable pulls with an audible click.
There is still no 4wd. Is there a problem in the differential? If so, is there something specific I should look for?
I found a fix!!! 2000 Sonoma 4wd would not shift from 2hi to 4hi. Tried the battery disconnect and it worked but only for a day or two. The more times I tried this it seemed the less time it lasted. I even tried swapping the tccm with one I knew to be good. Still had the same trouble with my truck. Broke down and brought it to a dealer and LO AND BEHOLD they found the trouble. Tccm was OK, no vacuum leaks, actuator was good, encoder motor was fine. Dirty, oxidized electrical connections on the tccm were causing the trouble. Cleaned them and applied dielectric grease. It's been a week and all is well. 4wd pops in and out just the way it's intended. Score one for the dealers.
Comments
you might have to change the vacuum actuator and or the vacuum actuator cable...not to difficult to do, it fixed my 4 wheel drive problem.
When your hub lock out switch fails, it can fail in the vacuumed position. This causes the front differential to be engaged which commonly breaks the thrust washer. I found the information on s10extremist.org in their technical articles link. Lots of great info there - even the instructions to fix it.
Further research, and not sure if this is as big a deal in the US as in Canada, but if you're replacing the hub lock-out switch on the transfer case the transmission experts recommend buying the part from a GM dealer - apparently the aftermarket parts in this case aren't that great. I had an aftermarket one break immediately (and I'd let my 2 yr old play with the receipt).
And lastly, if anyone can find a vacuum hose routing diagram that would be very helpful.
if not good luck!!
Anne
My 96 GMC Jimmy is doing the same thing now, have you had any luck in finding out what the problem is?
Summary: stuck in 4 high, changed encoder motor, changed tccm, still wont shift out of 4 hi. TCCM clicks, and light flashes on button, but goes to only one click and flash after trying it a few times.
I loved that small truck when it worked , once it falls apart there is no stopping to it...., here in Canada fuel pump replacement costed me $1300 lol after 1 year again the fuel gage failed after a year !!!! the fuel gage reader is in the fuel pump in the tank lol..., I need another $1300 to make my fuel gage work LOL !!!! now the truck rests off of the west coast in the ocean... I hope I never see that dancing fuel gage display ever again !!!!
brake sensor failed in the left hub and the right one was noisy. I don't think there is a solution for this problems. Just like there seems to be no solution for leaking intake manifold gaskets or the flaky fuel gauges or the failing fuel pump. The is a nice "little" SUV, when it runs!