no 4x4
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no 4x4
While turning sharp on dry payment in 4x4 hi heard a loud bang put into 2 wheel drive and drove home, now when you engage the 4x4 the 4x4 hi light comes on but the 4x4 isn't working, whats wrong?
Hotshot
Joined: Jul 2005
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the front axle on each end has a vacuum piston that pulls the wheel drive OUT of 4 x 4.. When motor is off, the vacuum is gone and the wheel is LOCKED up.. When you start the truck and get vacuum, the piston has vacuum and pulls OFF the 4 x 4..
When you switch the dash ****, to 4 x 4, an electric signal goes to t he transfer case and small motor engages the front drive shaft.. at the end of travel, a switch is contacted and that tells solenoids on the firewall to CUT the vacuum to the front wheels and engage them to the axle shafts which are being driven by the front drive shaft..
Put the truck in 4 x 4 and park. Lift front wheels off the ground and inch... crawl under and try to turn front drive shaft. It should be locked to the transfer case and not rotate.. If it turns and the front wheels turn, then the driveshaft is not engaged inside the transfer case....Either motor is not stroking the internals fully, or something broken... but you said you get the light, which I think means the motor is moving full stroke...... see if the driveshaft turns when in 4 x 4, with wheels off the ground.
When you switch the dash ****, to 4 x 4, an electric signal goes to t he transfer case and small motor engages the front drive shaft.. at the end of travel, a switch is contacted and that tells solenoids on the firewall to CUT the vacuum to the front wheels and engage them to the axle shafts which are being driven by the front drive shaft..
Put the truck in 4 x 4 and park. Lift front wheels off the ground and inch... crawl under and try to turn front drive shaft. It should be locked to the transfer case and not rotate.. If it turns and the front wheels turn, then the driveshaft is not engaged inside the transfer case....Either motor is not stroking the internals fully, or something broken... but you said you get the light, which I think means the motor is moving full stroke...... see if the driveshaft turns when in 4 x 4, with wheels off the ground.
Hotshot
Joined: Jul 2005
Posts: 11,931
Likes: 180
also note that the 4 x 4 is engage at the wheels when the engine/ motor is off and no vacuum... If you jack up a tire and try to rotate, it should not rotate. If it does rotate, see if it is turning the axle and drive shaft , or just spinning on the wheel bearing.
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cemcjoe
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Jan 28, 2014 10:40 PM
