Hello all, I'm new here on the Blazer forums, but no stranger to GM vehicles.I'm looking for a little help. I just bought a fixer-up Black 96 Blazer LS4x4 2 door. Needs a few things and I'm going to fix it up and sell it. My problem is: when I drive it around in 4 wheel high its fine, but when I switch it into 2 wheel high I get a loud clicking noise out of front of the truck that increases with speed. Sounds like baseball cards in the spoke of a bicycle. I'm not sure if the 4 wheel drive isn't completely disengaging or not but that's what it sounds like. I haven't really had time to look into it deeply yetbut I'm thinking 4x4 actuator, vacuum module on t-case, or maybe the actuator cable? I can hear the t-case switching in and out of 4 wheel drive when I press the button. It's a 3 button style 4x4 if that matters. I just did intake gaskets on the truck today so I haven't gotten to this issue yet. I'm sure I'm not the first one with thisproblem so anyone with experience I'm looking for Ideas. I want this truck fixed up and gone ASAP. Thanks all in advance!-Matt

 

Sounds like the front axle is not fully disengaging. I would see if pushing in on the cable (under the battery) resolves the clicking problem. If it does, you might want to lubricate the cable while moving it through its full range of motion. It may just have gotten sticky, restricting is motion to release the front axle engagement collar in the axle.

 

That's kind of what I was thinking and the direction I was going to go. I will try to get a look at it this weekend. I will keep everyone posted. Thanks

 

Ok I pulled out the battery and battery tray, disconnected the cable from the actuator and tried to pull it in and out. The cable would not move. I removed the cable from the truck and noticed the housing was broken but the cable moved once it was out and straightened. I tested the actuator with a vacuum tester and that is working as well. The metal collar that the cable connects to in the front diff is hard to move and only has about a half inch of motion. Is this normal? I can pull it out about a 1/2 inch, it clicks and stops, then I can push it back in about a half in. I'm not sure what the range of motion should be?? any help?? Thanks.

 

You likely do not have the gears inside the diff aligned properly to get it to fully engage. It should move somewhere around 3/4" to 1" if I remember correctly. Try spinning the front passenger wheel a bit while you pull on the collar inside the front diff.

 

what will that accomplish? I can get it to fully engage into 4wheel Hi (I believe) at least there is no noise. I can not get it to go into 4 wheel lo... I'm new to this truck so I don't know if there's a trick to that or not, but as soon as I click it into 2 wheel hi it starts grinding up front. I just reconnected everything and tried it again but it's not any better. I feel like there should be a lot more movement on the cable off the actuator but its really hard to move and it doesn't move much. Feels more like cable stretch than anything.....

 

Sorry... From your last post, it seemed that you were trying to get the front axle to engage. If 4HI works and 4LO does not, then you have a problem with the transfer case, not the front axle.

Your clicking is likely because the cable is not returning properly, but the no 4LO is all in the transfer case. Encoder motor problem is a likely culprit.

 

I was just trying to test cable/actuator and noticed that I didn't have much range in motion in the cable. I removed the cable made sure it moved freely, lubed it up and put it back in the truck. When i hit the 4wheel lo button I have nothing, didn't really mess with it bc I'm trying to get the 4 wheel drive to fully dissengage when I put the truck into 2 wheel. So far no luck. Everything appears to be working, actuator pulls in when in 4w, and releases when in 2w. (maybe vice versa, but its functioning) I can hear the motor switching backing and forth, but it's obviously not fully dissenging....

 

If it is clicking in the front axle, then you have a problem up front. When you had the cable off, was there a return spring in the housing where it attaches to the front axle? If not, there should have been...

 

Dont forget that you have to put the transmission into nuetral in order for the t-case to go into 4lo.