4x4 Still Doesnt Work!!!!

[diamond_driller]

hey There Again Guys Ok Here Goes My 4x4 Dont Work Ive Replaced The Selector Switch And Checked The Vacuum Lines And Fuse They Are All Good So Whatelse Could It Be?...and Whats The Proper Name For The Electric Motor For The Transfercase?......also My Fuel Mileage Sucks Ass Last Year This Time I Was Getting 200k From Full To Three Quarter...now Im Only Getting 140k.....p.o.s.what Do Yous Think Muy Problems Could Be?....thanks Again Guys....

[sleepy_eater69]

i think its called an actuator but im not sure but i think thats a problem with the 4x4 not working and for ur gas mileage try doin the small stuff first like new plugs and wires, air filter, fuel filter, and then put some injector cleaner in with a full tank should help a little bit

[97s104x4]

actuator on the transfer case, it goes bad, mine went out, junkyard time!

[LabRat116]

Dude. Cool it on the BOLD type already. People don't like to read that.

Anyways, what are the lights on your 4x4 dash switch doing ? Meaning are they flashing ? Does it engauge properly when you hit the buttons ?

What year is your truck/Blazer ?

S10s/Blazer are also notorious for have the Transfer case computer (located behind the passenger's side kick panel) go bad.

[Wheezy]

If the lights aren't flashing when you hit the 4x4 button and you hear the actuator motor on the transfer case clicking, then it might be the vacuum diaphragm for the front diff to lock in. You have to get a mirror to see it under the battery tray, or put your hand on it while the truck is running and have someone toggle between 2 and 4wd. Just be sure you don't get hung up on the fan belt or any of the accessories. The diaphragm on mine was completely gone and wouldn't engage the front axle when 4wd was selected.

[89Chubby]

Just a side note, if you're truly concerned about your gas mileage, stop trying to measure MILES PER TANK and start calculating your MILES PER GALLON (number of gallons consumed, divided by number of miles driven since your last fill-up).

Miles per tank is kind of a meaningless figure when it comes to figuring up your fuel economy; about the only thing a miles per tank figure is good for is figuring up your total RANGE if you're planning a road trip someplace and you need to decide in advance where you want to refuel.

[Wheezy]

In the winter months they put more ethanol in the mix, try bumping up to 89 to see if it helps out, I was spark knocking like crazy as soon as the mix changed. Also check your tire pressures and all the associated goodness that comes with tune ups, etc.

[Ky95S10]

Well there is the relay under the hood, or try to disconnect the Battery for a few mins, worked for me this week.

[johntkd]

Several things are common causes for this situation the first to check and verify is always the vacume diaphragm under the battery tray which engages the axle via a cable this is a very common issue,usually the actuator needs to be replaced however sometimes the vac line just pops off,
secondly the vacume switch on the Transfer case although rare it does go bad, another problem that i have encountered is the right axle "pops" out of the internal spring lock and when the vac actuator engages the differential that axle is unable to engage and you will not get front axle engagement.
a simple find to this problem is lay down to see under right side of vehicle you will see where the CV shaft connects to the output shaft from the axle where they connect try sliding that axle shaft side to side ( wheel to differential) if it moves its disenegaged in the differential, to correct push in very hard ( pry bar and hammer may be needed to seat it,till your hear it "click" if locked there will be no side to side play.

this problem is usually caused by a person running in 4x4 on hard dry surface roads and everything "winds up" from lack of slippage