jonathon
1/2 ton status
On a 4wd 2dr 1989 S-10 Blazer, how do the hubs work? Are they automatic or always engaged?
CK5
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S-10 Blazer Question
- Thread starter jonathon
- Start date
Pvt. Maggot
1/2 ton status
I believe the hubs have nothing to do with how the 4x4 works, when the transfer case is put into 4x4 it engages the front differential. I recently had some problems with my buddys 88 s10 4x4, I put a new hub on the drivers side, and the people gave me one for a anti lock brake blazer, and it acts like the brakes are sticking, and gets the rotor red hot. I'm not 100% sure. But maybe I can help out a little, and someone can answer my problem as well hah.
Well, Mr Maggot is on the right track, just missing a couple details. There are no hubs per se. What it has is in the front diff, on the passenger side, what would be a long axle shaft in a solid axle is actually two pieces that spin independent of each other until a sleeve/collar slides over and locks the two shafts together. Once this occurs, the front axle is able to distribute power to the wheels. Both cv shafts/half shafts are spinning whenever the wheels are turning, but until this collar locks the shafts inside the passenger axle tube together, the passenger side axle shaft in the diff spins and the driver side axle shaft in the diff spins the spider gears in the differential unit without spinning the carrier/ring gear.
How does the collar know when to slide over and lock the shafts together??
When the transfer case shifter is moved from 2hi to 4hi or 4low a vacuum switch on the transfer case is activated sending a vacuum signal to a servo. This servo pulls a cable which is attached to a fork that slides the collar to lock or unlock the shafts. If any of the vacuum comonents are malfunctioning the transfer case will spin the front shaft, but no 4wd will occur because the shafts inside the diff housing will not be locked together. The ring gear will spin, but it will not transfer power to the wheels. What it will do is spin the snot out of the shaft that goes between the differential carrier and the passenger axle shaft (the one that the cv shaft bolts to). Think of it as an open differential in the rear of a truck. The left wheel is on pavement and the right wheel is in mud with no traction. The tire in the mud will spin forever even though the left wheel has traction. Same thing in the front diff on an S10 when the collar is not locking the two shafts together.
This exploded view may help picture what parts do what.
The cv shafts bolt to items #1 and #31. #18 is the sliding collar that locks #1 (with a couple extra parts on it) to #19.
Man, this seemed like an easy qustion until I started trying to put it into type.
Hope it helps.
How does the collar know when to slide over and lock the shafts together??
When the transfer case shifter is moved from 2hi to 4hi or 4low a vacuum switch on the transfer case is activated sending a vacuum signal to a servo. This servo pulls a cable which is attached to a fork that slides the collar to lock or unlock the shafts. If any of the vacuum comonents are malfunctioning the transfer case will spin the front shaft, but no 4wd will occur because the shafts inside the diff housing will not be locked together. The ring gear will spin, but it will not transfer power to the wheels. What it will do is spin the snot out of the shaft that goes between the differential carrier and the passenger axle shaft (the one that the cv shaft bolts to). Think of it as an open differential in the rear of a truck. The left wheel is on pavement and the right wheel is in mud with no traction. The tire in the mud will spin forever even though the left wheel has traction. Same thing in the front diff on an S10 when the collar is not locking the two shafts together.
This exploded view may help picture what parts do what.
The cv shafts bolt to items #1 and #31. #18 is the sliding collar that locks #1 (with a couple extra parts on it) to #19.
Man, this seemed like an easy qustion until I started trying to put it into type.
Hope it helps.
guz71
1/2 ton status
there always engaged(front axle shafts are always spinning). Im not sure on the older s10's but I think the front axle disconnect is thermal actuated. By some process, a coupling is slid over and "locks" the axle shafts up.Like I said not real familiar with the s10's but I know the hub(more like a drive flange kind of) is always engaged.
edit:beat me to it when typing, my mistake vaccum actuated
edit:beat me to it when typing, my mistake vaccum actuated
In 1988 there was only one rotor for a 4x4 S10. If it had anti-lock the reluctor ring would have been on the cv shaft or in the bearing hub itself and had nothing to do with the rotor so I wouldn't be able to venture a guess on that one (I don't think ABS was even an option in 1988--could be wrong though). Are you sure it was looked up for a 1988 and not a 1998??
Pvt. Maggot
1/2 ton status
They gave us a hub, where the bearings are that the axle fits through, and it was for a blazer that had anti lock brakes, and after replacing the hub, the brakes would get red hot, I tried switching the rotor from one side to the other to see if maybe it was bent, but the same result, and the only thing I can think would be that its that hub.
EDIT: also, I replaced the axle as well, and while test driving and knowing that side was not working right, it sheared the bolts on the differential where the axle bolts up, which makes me think the hub was sticking, causing the axle to move slower at the wheel and caused the bolts to break.
EDIT: also, I replaced the axle as well, and while test driving and knowing that side was not working right, it sheared the bolts on the differential where the axle bolts up, which makes me think the hub was sticking, causing the axle to move slower at the wheel and caused the bolts to break.
jonathon
1/2 ton status
the vaccum ones suck...... theres a company that makes a posi lock that does away with the vaccum systems.... jeep YJs had the same kinda thing goin on...... just SAS it using a Jeep YJ front axle and call it done
I have two of them in my driveway with a combined total of over 320K miles on them and haven't had a problem with either of them. So with that, in my opinion, I'd say they are pretty reliable. The Posi Lock deal is a good alternative, but if yours works as is, I'd run it.
