4x4 has not worked in a year

[PimpingA1997Jimmy]

ok i bought the 97 jimmy about a year and a half ago it was working when i got it but it stoped working about a year ago
what hapend is i was on the highway and i engage it on the fly i hear a grinding noise when i would try to put it back in 2wd and if i put it in 4x4 it would work find then all of a sudent i heard a pop and put it back in 2wd
the problem is i can push the 4x4 button and everythign clicks in and sounds liek it is trying to kick in and it even indicates that its kicking in but im looking under the truck a friend a few months ago and they tried to turn it manualy and the rear end is not kicking into the axl is that making sence ?
what do ppl here think the problem could be
The car drive but the 4wd wont work

[lt1s10onair]

ok, first.... do u have an electric actuator on the front diff? its a black plastic plunger on the pass. side of the diff. (parallel with the axle tube)
if u do, unscrew it, and switch from 4x4 to 2wd etc. and see if its extending out & contracting..... if its not, its prob the encoder motor, or a faulty plunger..... if it has power to it, its the plunger......
now if it does move, its the diff

[PimpingA1997Jimmy]

ok cool ill check it out and see what its like i havent looked at that yet it ift the plunger or the diff is that a exspensive fix ?

[MikeInCtown]

Stuff is cheap at boneyards. Give them a call once you figure out what is wrong.

[gchemist]

I have some 96 factory manual 4X4 pages scanned. Send me your e-mail address. I'll send you some PDF files.

[lesterl]

Possibly switch on dash? Was bad on the 98 blazer.

[MikeInCtown]

Dash switch went on my 2001 as well. Replaced it and now I can hear all the relays clicking in and everything. Since he said he can already hear all that I'm assuming he's got a hardware problem underneath. He's got a 97 and he lives by me in Cleveland and I KNOW there are a lot of those year Jimmys and Blazers floating around at boneyards.

[logicblazer]

I dont think that you are able to switch it into 4x4 on the HIGHWAY that to me is just asking for something to break going that fast and having the front diff trying to catch on.

[beaniebmx]

your supposed to be at a crawling speed, and 4x4 is not meant for highway/roadway use, only on dirt and snow and ice where needed.

the dash switches go out alot, mine on my 2000 did, the light is never on, i have to hit it a few times before it lights up and a nice bump turns it off, if i move the wires connected to the back, it will sometimes stay lit

[PimpingA1997Jimmy]

i only used it on the highway in bad snow storms and ice storms and would kick it on if i found myself in trouble and sliding on the highway

my dash switch went out also about 9 months ago thout that was the problem so started looking into it found out that the problems iwth the dash switches alot are just the fuses i forget what fuse it is but check our fuse and replace that befor eyou go get a switch if all u need is a fuse

[logicblazer]

If your blazer is anything like my trailblazer then to go into 4x4 it is suggested that you need to be in neutral then you can activate it. And i guess that the blazer and the new trailblazers have the same 4x4 system just about because you can only use it on slippery road conditions otherwise you'll snap a CV axle.

I would have to say that maybe you snapped something maybe your CV axle (if the blazers have IFS) it might not look broken so you would need to check out if ANY tires spin if not start with axles or T-case.

[orangesonoma]

Quote: Originally Posted by lt1s10onair

ok, first.... do u have an electric actuator on the front diff? its a black plastic plunger on the pass. side of the diff. (parallel with the axle tube)
if u do, unscrew it, and switch from 4x4 to 2wd etc. and see if its extending out & contracting..... if its not, its prob the encoder motor, or a faulty plunger..... if it has power to it, its the plunger......
now if it does move, its the diff

its not electric it is controlled by vacuum...and if that does not work it could the actuator for it or even the switch on the transfer case...or a cracked vacuum hose

[PimpingA1997Jimmy]

a friend told me that he tried to manualy engage the 4x4 front wheels but he could not get them to spin so not sure whats going on he said he thinks it has to do with the rear end where it is suposed to lock into the front axles and shaft or somthing like that

[logicblazer]

there should be the engine which goes to the tranny which is connected by the driveshaft which turns the rear end.

next to the tranny should be an extension that is connected by another driveshaft that goes to the transfer case which turns the front axle.

if im not mistaken that is the rear end would have nothing to do with the front axles not turning if ther was something wrong with the rear end you would know it by not moving.