4x4 not engaging

[steelhorserider0891]

in my 89 blazer, i can put it in 4 high or 4 low the linght will sometimes come on or it will flash , but never feels like the front end has been locked in.. is there something between the shifter and front diff that can go bad to not let it lock in.. looked like jus a cable or wire goin into the back of the diff? thanks for the info

[67Truckin]

Sounds like the actuator on the right fenderwell is going bad. It is supposed to heat up a gas which makes the cable move in or out which moves it at the differential. These are known for failing.

[Rinkrat456]

You are correct, and usually it is that vacuum cable that goes bad. Under your battery tray there is a vacuum switch that is triggered by your t-case. You shift into 4HI/LO, and the t-case shifts the front passenger axle shaft into place, locking the differential. Sometimes battery corrosion, rust, water - you name it, can prevent that vacuum switch from locking in the axle shaft so even though the t-case is engaged, the front diff is just spinning, not turning the wheels.

There are a few things you can do to test this, one is just to remove your battery and battery tray and look for the vacuum switch connected to the differential via a black cable. Jack up the front wheels, and when you find the switch, press hard on the switch by hand and it will lock the axle shaft in place. Try spinning the front wheels by hand. If it locked correctly, you shouldn't be able to turn your front wheels freely if the t-case is engaged in 4HI/LO. In this pic you can see what to look for, and if need be, buy this as a replacement.

http://cgi.ebay.com/ebaymotors/Blazer-4x4-4wd-actuator-setup-Jimmy-4wd-Chevy-s-10_W0QQcmdZViewItemQQcategoryZ46093QQihZ020QQitemZ 300182483684QQrdZ1QQsspagenameZWDVW#ebayphotohosti ng

Another way to fix that is to remove the vacuum switch all together. Posi-Lock makes a hand cable kit that replaces the vacuum switch, so when you need the front differential, you push or pull (can't remember the schematics exactly) the hand cable inside the cab and the front differential locks in the axle shafts. It's what most of the hard-core guys do if they've had trouble with their electronic setup. It's a reliable way to ensure there's always 4 tires turning, since with the manual cable setup it's either locked or unlocked, no guessing or hoping the vacuum switch works.

http://www.s10extremist.org/tech_articles/posilock.htm

[Rinkrat456]

Dang it 67Truckin, you beat me to it. :D

[67Truckin]

Dang it 67Truckin, you beat me to it. :D
Yeah, but your response gave it a whole lot more detail than I did. Good job! :)

[steelhorserider0891]

auto zone said there was nothin else in between..lol i know what put ti is and where its at seen it before. as soon as i get a chance it'll be replaced already ordered it. ... does anyone know who sales just a set of lift spindles? have found them but they come with a whole bunch of other crap that i dont need. thanks for the help.. always helps if someone else has already been there i guess.

[Rinkrat456]

Anyone have any idea of what he's talking about?

[67Truckin]

Anyone have any idea of what he's talking about?
He has the part ordered to fix his 4x4 actuator from Autozone. Also, he is looking for lift spindles for his front hubs. There are no lift spindles for a 4 wheel drive that I am aware of. They are a 2wd item. 4wd trucks usually have drop brackets for the A-frames and differential housing brackets to essentially move the entire front suspension down along with different torsion bars or torsion keys.

Rink, can you expand on this for him as you are our 4x4 guru. :)





Built......not bought! :cool:

[Rinkrat456]

There are no lift spindles for a 4 wheel drive that I am aware of. They are a 2wd item. 4wd trucks usually have drop brackets for the A-frames and differential housing brackets to essentially move the entire front suspension down along with different torsion bars or torsion keys.
I would have said a bit more on cranking the torsion bars for an inch of lift, ending with exactly what you said. The only 4wd lift spindles I have seen are custom pieces not available to the public. So, well put 67Truckin.

...Haha, bought, built, then pieced together. :cool:

[kenneth.caratello]

sounds like he has the electric actuator for the four wheel drive going bad. It just unscrews from the differential and has a plug in. I think the 89 has the electric system and the 88 has the vacuum systems