Help with Chev front diff

[Rip_Tear]

Long story short, my front diff isn't spinning my front tires... The truck is a 95 Chev V6 4.3L 1500 1/2ton (4x4 ovbiously) it's an auto (sadly).

The shaft is spinning from the transfer case to the front diff, there is fresh oil in the diff, the light on the pic for the 4x4 doesnt light up when I switch into 4x4. There are no odd noises when I switch the drives. There are no lockers on the front hubs or anything.

I know I can take apart the diff and see if anything is broken, but any have any ideas, or ways I can test to see whats broken. Or how to test if the electronic parts are working.

[TCracin440ex]

that sounds to me like a vaccum line....

[TM426]

I believe he is correct^^^^^^

[Warrioreater400ex]

yup what they said, ive got manual hubs on my yota, so im not completely sure where they disengage the axles at, but it should be the hub, so when you lock it in 4x4 your u-joints should still spin (theoretically)

[MOFO]

I thought the hubs on a Chevy of those years were a thermal type of hub.... and the vacuum line did the transfer case....I could be wrong..... :confused:

[Rich250RRacer]

Should be electronic solenoids on this truck, although I could be wrong. I know it's common for the solenoids to go bad. Since I work in a parts store, I know they're available aftermarket, from Dorman.

[Warrioreater400ex]

u-joints... pshh sorry i forgot to look at the year disregard that post i was still thinkin solid axle... In that case its push button,


you said your front driveshaft is spinning.. how did you test this.. on blocks or just putting it in 4x4 and driving it

are your axleshafts and cv's not turning?

i would get a haynes or chevy shop manual... it makes things easy and pays off in the long run..

[kicken250x]

get the truck up on stands/lift so all 4 wheels are off the ground, put the transfer case in 4 hi and the tranny in 1 (let the wheels spin but have someone with their foot on the brake so they dont spin to over 1-2 mph, look to see if the drive shaft is spinning. no? transfer case problem yes? transfer case is ruled out, now go to the front end and look at the CVs are they spinning? no? cracked or disconnected vaccum line. yes? get a manual and pull apart the hubs and check for damage. hope that helped some

[Schooled 416]

On my old s-10 (91) I had a vacuum switch in the transfer case stuck open, and a vacuum line cut. (was like that when I got it) But, during 92-94 chevy had alot of changes in their trucks.

[Sportrax10]

http://www.4x4posi-lok.com/

Buy one of those...

Its a common problem... I have to get one myself... :o

[Rastus]

As far as I know, there is no real "hub" per se on these trucks. The CV shafts are engaged internally in the front diff.... Or atleast that's how it seems on mine. :confused:


Personally, I think it's the actuator that goes into the front diff. You said the front driveshaft IS spinning, so I'm assuming the transfer case is working. I'm not sure what your trucks' options are as far as push-button or pull-back stick, but it should be similar with either system. I've heard of this happening before, but to be quite honest I've never done it before myself.

Your best bet would be to check out Fullsizechevy (http://www.fullsizechevy.com) or Chevytruckworld (http://www.chevytruckworld.com)

Either place has tons of info. :cool:

[prepracing]

Originally posted by Rastus
As far as I know, there is no real "hub" per se on these trucks. The CV shafts are engaged internally in the front diff.... Or atleast that's how it seems on mine. :confused:


Personally, I think it's the actuator that goes into the front diff. You said the front driveshaft IS spinning, so I'm assuming the transfer case is working. I'm not sure what your trucks' options are as far as push-button or pull-back stick, but it should be similar with either system. I've heard of this happening before, but to be quite honest I've never done it before myself.

Your best bet would be to check out Fullsizechevy (http://www.fullsizechevy.com) or Chevytruckworld (http://www.chevytruckworld.com)

Either place has tons of info. :cool:


YES SIR, 95's and 96's are notoruis for the actuator going out, and like MOFO said they are thermal activated. The actuator just isn't heating up to engage the anything

[underpowered]

it is the thermal actuator. notoriious for going out on those truck, there is a company that makes a cable actuated lock system for them. gives you positive engagement and the option of 2wd low range. Check ebay, i believe they are called tru-lock, but not sure on the name.

[Rip_Tear]

thanks for all the info guys!

I already have it up on blocks, all 4 off the ground, I know its not the transfer case, the shaft from the transfer case spins up to the diff. The axles off the front wheel hubs spin back the the diff, if I spin the wheels by hand.

My shifter is a stick type, not push button. I think I under stand the part about the accuator, I think I just took it out (lol) is this it?

[Rip_Tear]

oh, I tried hooking this up (the electrical part) and left the other bit out of my diff, should it have done anything? When I was switching between 2wd and 4wd?

[duke416ex]

That would be it, the end should have went in and out as you put it in and out of 4x4.