4x4 wont engage

[raptorforme93]

Hello Im new to the forum. I drive a 1996 2dr 4x4 Tahoe LT with 165k on the body and about 80k on a new engine and tranny. I have had the truck for just over a year and the 4x4 has always worked fine but I went to use it the other day after not using it for almost 2 months and it wouldnt engage. I press the 4x4 hi button and you can hear it click over like its going to engage but the botton just blinks and it doesnt engage. I tried it several times going into 4x4 hi and low but neither engage and I also tried to get it to engage while rolling forward at idle. Any ideas of what it could possibly be or any similiar problems? All input is appreciated! Thank you

 

[blueflamed03]

a buddy of mine told me it's a simple elctronic actuator in the top of the axle...like an $85 part?

 

[raptorforme93]

Did he have a similar problem? I hope its not a big problem. Id like to get it working again

 

[crmzendrgone]

sounds like it is the actuator easy install but it could be the one on the tcase itself. pull the one out of the front axle and have some one press the buttons if it moves than it is the one on the tcase if not then that is the one you'll need to replace. 90% sure it is the front axle actuator.

 

[96ProCompTahoe]

a buddy of mine told me it's a simple elctronic actuator in the top of the axle...like an $85 part?

x2 on the actuator`

 

[raptorforme93]

Alright Ill try to look at it this weekend. You dont think that its anything serious? Thank you for the help!

 

[niterunnr]

im having the same problem on my 98 hoe... ebay has that actuator for 78 bucks.. thats the cheapest i can find... bought mine yesterday and when i comes in ill let you know... also bought a new switch just in case... i took a small brass bushing and put between actuator and front diff. housing just to get my 4x4 working... it works fine with is but i dont drive it very far....mine is the big electrical one that has 4 wires on it.... o"rielly wanted $120 for it.. monster had it for 90... search ebay real good and eventually youll find one for 78

 

[blueflamed03]

cool, let us know how it turns out raptor!!

 

[bowtiefreak]

A little late but I agree with the actuator

 

[raptorforme93]

Let me know if that fixes it niterunnr and Ill check out my 4x4 on monday when I have some free time. I also have to take apart my dash to rewire my stereo so that will be a fun day. haha

 

[raptorforme93]

Have you gotten the parts yet niterunnr? I want to know how yours turns out before I order up parts...

 

[mash]

hi
my 1998 2 dr hoe the 4x4 selector switch is very un reliable, most of the time there is no light, some times 2hi lights but it goes out soon after. it is shifting to low gear dont know if the wheels are engaged or not. no flashing of any lights, can some one help me with a little guide line steps to troubleshoot.

thanks a million

 

[raptorforme93]

Another guy had a similiar problem in the general section I think. its labeled something about his 4x4 not engaging. He just replaced the switch and everything was all good

 

[96Yukonguy]

i had the same problem on my 96 4 door i replaced it with a 4x4 Posi-Lok 600 system from summit.... 202.95 and no worrying about getting it wet or it coming unplugged

 

[raptorforme93]

and that fixed your problem?

 

[Provolone]

i cant get into 2hi

going thru the same just flashes.soon as i start the truck it goes to 4hi if i click auto it would go right in but then i would be able to hear it trying to engage here n there.then if i decide to enter 2hi 2hi would just keep flashing then all of the lights would disappear and "service 4wd" comes on....

 

[raptorforme93]

Ok so I finally got a chance to look at the actuators today (just look not take apart) and this is what I found. The rear actuator apears to be working great but the front actuator makes no noises of any kind at all so im assuming that its shot and is what is causing my problem. Also I took two pics of the actuators because Im just assuming that what I was looking at up front was the actuator.

Rear actuator that seems to work perfectly

Front actuator correct?? Makes no noise of any kind so im going to guess that this is why my 4x4 wont engage

 

[raptorforme93]

No one?

 

[SunlitComet]

You are correct. The t-case unit is a stepper motor actually.

My t-case works but my selected light blinks and no sound from the front. I should be replacing my actuator in the next week hopefully.

Rapto use the diagram below and put a fused 12v on the light blu wire of the actuator and ground the black to test it.

I would like to add that http://alldatadiy.com/about_alldata/index.html has a subscription for vehicle tech info major chains use it dealers use it and it cost less than $25 for the first year/vehicle. It contains very detailed info on everything the factory provide however while it will tell how to tear down a transmission for example with parts, fluid circuits and electrical diagrams it will not tell you how to change your oil. It's a lot of factory info.

I highly recomend it along witha haynes and chilton book. It is still cheaper than massive phone book sized manual set which I will get next year.

In the case of 4x4 there is over a dozen documents on diagnosis charts and theory of operation alone and they are all printable.

Mash, if you can provide a fax number I can send all the tech info I have printed so far on the 4x4 system include your attn: info for the cover sheet please. Rght now it would be easier this way.

As long as I have the time I will try to help everyone else. here is some examples:

View attachment 6638

View attachment 6639

View attachment 6640

View attachment 6641

 

[SunlitComet]

Sorry it will not enlarge pictures. Perhaps you can downlod the and resize?
Damn that doesn't work eathier.