4 weel drive problems

[derekBer]

i purchesed a 92 blazer s-10(cpi) ..... not too long after i started to have troubles with my transfer case. i took it into a local transmission place (a very dumb idea) they ended up replacing the entire transfer case........ the problem went away and now about 3 months later i have the same problem. the truck goes into 4 weel drive, then all of sudden it will make a loung grinding noise...... after stoping the truck and putting it into park i can get it to come out of 4 weel drive....... the guy at the transmission place says he thinks it is something to do with the computer?? and isn't covered by the warentee

[derekBer]

any ideas what it could be?

[crazys182003]

well if you are mechanically inclined maybe you could start doing some checks on it yourself. I am not that advanced to know where much is but afetr doing research on here numerous times for 4 wheel drive problems I believe what you might wanna check is the vacum. But if it is a computer problem once you have it stuck in 4 get somewhere that you can sit for a couple minutes and disconnect the negative side of the battery for about 10 mins than reconnect that would reset the computer if it would be that. I am thinking maybe it is not fully engaging your 4 wheel drive sicne it is grinding. I am not sure but are there hubs behidn your wheels which actually engage to make the wheel turn? I know other trucks do b/c I have had other classmates have to replace but I really am not too positive on that. If there is a hub or soemthing than maybe it is shaved down or the teeth aren't catching and might need replaced.

[s10blazerman4x4]

id check under the battery for the actuator and see if the vacuum hoses there are kinked or disconnected.follow them accordingly and repair them and hook them back up and then try it.

[derekBer]

i took it out and got the 4 weel drive to make the loud grinding noise..... i then put it into park(the noise stoped) and shut it off. I waited about 10 mintues with the negative side of the battery off. It did not help and i manged to get it to make the noise again......... when i got home i took a look at the actuator and the vacum hoses and didn't notice any damage...... what should i look for on the actuator that would tell me it is faluty?? I also took a look at the front differitional fluid....... it was gray and very dark. is this normal? could this be an indication that the grinding noise is coming from there?

[BlazerLT]

Is it an electronic 4x4 or the floor manual one.

[derekBer]

it is electronic

[BlazerLT]

I you replace your differential lubricants.

It should be light brown to honey color when new.

I would look for a bad wire going to the encoder motor on the transfer case.

[derekBer]

is there any easy way to drain all the differantial lubercant??

[BlazerLT]

I believe the fron has a top fill and lower drain plug.

I may be wrong. If not, you will have to buy one of those pumps to extract it yourself.

I have my diff fluids changed at the local jiffy lube seeing it was a lot more convenient than doing it in the driveway.

They handle the mess.

[derekBer]

thanks i will try that. I still would like to know how to tell if the actuator is faluty? any sugesitions would be great.

[derekBer]

well i am still having poblems....... i changed the front differental oil..... and traces all the vacume lines back and they all look ok. i don't know what else to check could any one help??

[BlazerLT]

start looking at your vacuum actuator and encoder motor.

[derekBer]

well all the vacume hoses look fine....... and the encoder motor wires look ok?? it seems to go into 4 weel drive fine it is just when it is in it wants to jumb out

[blazes9395]

I had the exact problem. It was a humming/grinding noise when driving and during deceleration. Turned out to be a worn drive axle joint. I jacked the front up, put in 4x4 to lock the front axle and differential, and turned each front wheel and looked to see each front axle turn. The upper and lower cv joints should turn together on the axle if not, you have just found your problem.