Chevrolet Repair: chevy S10 4x4 problems, oil pressure gauge, chevy s10

Question
hi van. i just bought a 88 chevy s10 4x4.nice shape. 2.8, v6, 5 speed.the motor was repaced recently.with the same size and yr. motor. 3  problems,if u have the time. first, when u shift in and out of 4 wheel drive sometimes it goes back into 2 wheel drive and some times, the lever is in the 2 wheel drive position.and the diagram on the console is still lit up indicating its still in 4 wheel drive ..is there an adjustment on the linkage or something that could possibly correct this..the way it it ,im not sure if im really in 2 wheel drive or not..second question..my fuel gauge and oil pressure gauge goes crazy  sometimes..gas gauge goes way up to full then down to empty, it just jumps all over the place,. and the oil pressure gauge,goes from normal pressure to nothing, and then goes back to normal again.or stays down i know theres oil there ...could these both be sending unit problems..happening at the same time ,or a bad ground somewhere.im confused...any help or comments would be greatly appreciated..i do do some of my own mech.work.if its not to extreme.again thanks for any help ar advice u can lend me....john miller  

Answer
Hi John,
The front axle has an actuator that engages after the transfer case is engaged.
Then after the transfer is shifted to two wheel drive, the axle actuator will release.
If you maintain a torque load on the front diff, it could actually stick in the engaged position, which would also keep the console lit.
Check the tires, and see if the front tires are a noticably different circumferrence than the rears, like two tires much newer than the other two.
If that is the case, just shift to two wheel drive, and then back up just a little bit, to see if it releases.

It is also possible the actuator is sticking. Some S10's had a vacuum chamber under the battery box, and it is connected to the front differential housing with a cable in a sheath. That cable could possibly stick.

Where it connects is to the right side axle tube, where it bolts to the diff housing.

Check the following links. They are pretty much aimed at full size Chevies, but they work alike.

http://www.4x4posi-lok.com/PDFs/troubleshootguide.pdf

http://www.pirate4x4.com/tech/billavista/PR-shaft/index.html

http://offroadltd.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=ORL&Product_...

The gauges sound like a loose wire connector, possibly where it plugs into the back of the instrument cluster.

Van