got my c.v. shaft seal changed, now it appears that the front axle dissconnect is not dissconnecting. with the t.c. in 2wd i can jack up either front tire and the driveshaft turns. that shouldnt do that, right? aside from a little mpg loss, would there be any bad long-term effects from leaving it alone and being a "live axle"? i know the t.c. is switching from 2wd to 4wd. id assume the axle vaccum acutator only needs vaccum to engage the axle. am i wrong and need to do my tire off the ground spin test with the engine ideling? found out that the parts blazer has the different front axle (cv shafts have a 6 bolt flange, the '97 good truck they just plug right in to the case) the acutators look the same though. at least if im leaving it as a live axle, it will now keep oil in the housing rather than spraying the left side undercarrage!

 

No real bad side effects so long as it is fully engaged and not partially engaged.

You are correct in that the vacuum actuator only needs vacuum to engaged the front axle. Springs should return the cable and disengage the front axle.

The axles are very similar with the only real difference being the bolt on CV shafts instead of the splined ones.

 

Can you tell me more about how the front axle ingauges and disingauges, i have a 98 S-10 Blazer 3 buttom controller and it seems my front axle is not ingauging all the way when i put it in 4H or 4L i have changed the aquator, i get a very loud clunk when i accelerate in 4H or 4L i also have a noise that is at wheel speed in the front when in 2H, Thanks for any help. Sulley

 

There are a few posts around here that describe this and I have posted exploded views as well as an actual picture of all of the parts disassembled. I just don't have the time at the moment to find them. A browse through the 4wd related posts in the Tech Article (DIY) Index link in my signature should may turn them up. If not, maybe another member can find them before I get back to this thread.

 

found out what my axle issue is, at least partially. the acutator has full vaccum all the time! not sure if its a vac hose switched or a stuck switch, ive read some different threads about it. for now ive pulled and plugged the hose going to the acutator, going on a long trip tommarrow, be intresting to see if the fuel milage improves much, gets 22/23 highway now, cant imagine it doing any better. usually it seems this design has problems with the axle not engaging, while mine is just the opposite, not having a disconnect. i'll have to explore it more next weekend when i have time. for now its just a 2wd.

 

Thats what mine is doing to, i will try that today, maybe someone can tell use if there is suppose to be vacume to it all the time or just when it is in 4 wheel drive. Sulley

 

At the risk of sounding redundant, have you checked out the thread linked to in Kyle's signature entitled "Common 4x4 Problems"? I used that information and found that my difficulty disengaging was due to a combination of a rusty/seized cable between the actuator and the front diff. Took it apart, lubricated it, reinstalled it and the problem is gone. I also had vacuum when I wasn't supposed to so I also replaced the transfer case switch. 4x4 is back to normal!

 

i have read something about that, just havent had the time to check mine out, on my 161 mile round trip i got almost 22 mpg. wife had been getting about 16-17 around town with the front axle engaged, i told her to keep track of milage a while longer and see if theres any difference with the front driveshaft not turning now. ive got some time before the snow hits to get the 4wd straightened out and working correctly.

 

I just checked it out and i have vacuum to the actuator when it is in 2H, i am going to change the transfer case switch. Thanks for the help. Sulley

 

i was just thinking that right before i got this vehicle, dad had took it in to get a transfer case input seal changed, so the transfer case has been out and possibly has had a couple of vaccum lines switched. i looked underneath and it almost looks like im going to have to pull the front driveshaft to get to that switch with the 3 lines attached to it. lot of stuff in a tight spot.