I have a 97 Jimmy, earlier today it started randomly going from 4Hi to 2Hi. It is a push button not a stick that changes in and out of 4 wheel drive. It is now back in 2Hi and hasnt done it again, though now i cant shift into four wheel drive at all. Any ideas on whats causing this problem? If you need more information let me know what else yall need to know.

8/11/2006 6:15:34 PM

is it actually the electronics shifting it in and out, or are you just losing front wheel drive randomly?

it's either a vacuum leak, faulty vacuum disconnect unit, or the electronic servo/motor deal on the t-case. you can narrow those options down if you can discern whether the cause is mechnical or electrical.

8/11/2006 6:19:50 PM

earlier was it actually shifting from 2 to 4 and back or was the light just blinking?

8/11/2006 6:31:44 PM

i was just driving from my place over to wendys and the light on 4hi started flashing randomly meaning it was trying to switch over. It then went solid so I assume it was then in 4Hi. By the time i got over to wendys the 4 hi started flashing again then turned off. It did this several more times then went back into 2hi. I never pushed one of the buttons so i dont know why it tried to shift to begin with. Now my buttons are unresponsive, so since the buttons are unresponsive you think thats an electrical problem?

My dad thought it might either be a bad seal causing fluids to leak into the transfer case. he also suggested that when the new transmission was put in(which was done by the previous owner, who has never used the 4 wheel drive on it) and the computer might not have been reprogramed. I have all the matince records from the previous owner(he kept a very thorough record of everyhting done to it) back in Charlotte so i could call home and get any information that might be helpfull in troubleshooting

[Edited on August 11, 2006 at 6:33 PM. Reason : ,]

8/11/2006 6:32:51 PM

you would notice a difference in the way it drove and turned if it was actually in 4wd.

8/11/2006 6:38:02 PM

yup, it would be very noticeable on pavement when you turned if it was actually in 4hi. sounds most likely to be an electrical issue. check the connections, fuses, etc. in the system first.

8/11/2006 6:43:53 PM

ok i am getting ready to go to the gym so i can check that out when i get back, any other suggestions, tips, ect?

Me and several friends where planning on going down to carolina beach and camping out on the beach and stuff, but it would be extremely difficult to drive on the beach in 2wheel drive i would think

8/11/2006 6:53:58 PM

its a jimmy, my grandpas bravada had 2 transfer cases, a transmission, and three computers put in it, under warranty, its a bad bad setup. took me three weeks to find my 01 silverado with a floor shifter, found some good deals on pushbuttons but ran away from them

8/11/2006 10:22:01 PM

this is an extremely common problem. i thought you guys were supposed to be smart?

8/12/2006 2:10:04 AM

it's a pushbutton which = teh suck

8/12/2006 2:15:45 AM

yeah, get a dial like my ford... it kicks ass, only takes like 5 minutes to get it into and out of 4wd.

8/12/2006 2:49:45 AM

the 4runner has a dial, but its just for hi/lo cause its full time 4wd

8/12/2006 1:39:02 PM

You could have a push button nigger problem...

8/12/2006 6:11:27 PM

or 6 gallons of tranny fluid in the case, thats one more shirt permanantly stained

8/12/2006 8:38:12 PM

shit stained my shirt too... good thing it was one of those free shirts they are always passin out around campus

8/12/2006 9:25:43 PM

OK now my shit is stuck in 4 hi and i cant get it out, anyone care to help me get it back out of four wheel drive? After I do this I am pulling the fuse untill I have time to fix my shit right

8/13/2006 5:20:23 PM

my 2000 silverado and all of my friends have had this damn problem...i'll bet ya money its the damn switch on the dash...as in if you walk into the dealer tell him wahts going on he will just reach under the counter and get one...i just dont know if your switch is the same as mine...but if it is i'm sure its probably your problem....unfortunatley from the stealer they are like 60 dollars

8/14/2006 12:51:08 PM

^ 2nd that, on full size gm vehicles 99 and up anyway, I don't know about the jimmy

8/14/2006 3:10:13 PM

i have been doing some research and that is probably what the issue is, that along with the bad seal to the Transfer Case that dumped an extra quart of fluid in the transfer case. The switch is the same on all Jimmy's Blazers and Sanoma's from 95-02 if i remeber correctly

8/14/2006 6:17:45 PM

i'm still not understanding where you're getting the idea that the fluid was tranferred through a bad seal. i'm not aware of any nv case equiped vehicle where fluid from the transmission is at the t case input shaft seal at all times.

i mean, i guess it is possible but your transmission output shaft seal would have to be bad in addition to the t case input shaft seal. a transfer through vent lines sounds more probable to me, assuming the extra fluid is even the result of anything more than an overfill.

8/14/2006 10:31:42 PM

But I thought it was pretty much impossible to overfill a new process case unless you've got the front end parked in a ditch or something.

8/14/2006 10:33:12 PM

^ tranny fluid is low, transfer case is overfull, doesnt take a chemical engineer to do that mass balance, and its common on those, only the trans output seal has to leak, the input seal is good at keeping fluid in the transfer case, but not keeping transmission fliud out

8/14/2006 10:35:17 PM

I see...Well, dropping the t-case ain't hard.

8/14/2006 10:39:02 PM

it is a pretty complicated procedure for checking the tccm, it uses a computer and four magnets on the actuator with a hall effect sensor to determine gear position, but if it is the switch, you should be able to unplug it, jump from the pink to the dark blue wire, and it will go into 2wd and stay there as long as the switch is unplugged

8/14/2006 10:43:19 PM

it must not be too common, my wrench time has included a ~2 year stint at a gmc dealer and never saw such an issue. if that's what happened, why no leaking fluid from the 6 bolt t-case to trans mounting point? it's not a sealed connection IIRC? you could be right, but like i said i think things would have to be "just" right for it to happen like that. throw some fluid in the trans and make sure the vents aren't shared, see what happens.

Quote :

"new process "

yo they be new venture now ngr.

Quote :

"But I thought it was pretty much impossible to overfill a new process case unless you've got the front end parked in a ditch or something."

not any harder than anything else with a fill plug if it's not level, and lord knows i've seen how many countless differentials, manual transmissions, etc. overfilled. like i mentioned before, imo my first thought would be fluid puked back through vent lines. i don't know about his, but alot of those trucks connect back to a common vent.

8/14/2006 10:48:30 PM

btw, i'm pretty sure i've got one of the actuator deals around still attached to a cracked case in the event that's what it turns out to be. free assuming i can find the damn thing.

8/14/2006 10:51:48 PM

somethin aint right, and i did about as much diagnosis as taking out the fill plug, letting 2 quarts drain out, and sticking it back in, and peckerhead topped off the transmission which was a couple quarts low, otherwise i was too busy laying blocks

8/14/2006 11:00:53 PM

yeah, well... i certainly wouldn't consider my speculation over the internet any better than your amount of diagnosis.

8/14/2006 11:07:06 PM

for those of you interested in how this turned out i changed the seal this weekend as well as flushed all the vacume hoses and changed the actualy push button thing. Everthing now works perfectly and no more leak

9/5/2006 10:03:58 PM

so you really have no idea on what the cause was now do ya?

9/5/2006 10:15:55 PM

^^ you still need help movin that kegerator?

9/5/2006 11:07:14 PM

^^i think it was a combo of the vacume lines getting fluid in them and the button not working properly

^yeah it would be nice when you free Keith?

9/6/2006 12:50:31 PM

maybe tomorrow night or late friday night, i need my cooler back before the game saturday too

9/6/2006 9:12:01 PM