Auto hubs, again
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Postmaster
Joined: Jul 2003
Posts: 2,976
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From: Rep. of Texas
Auto hubs, again
I hate to post this, but no one ever answers my question under someone else's post.
But, where are the auto hub vacuum lines on a 4x4 1993 IDI turbo Diesel?
It wont engage, but the front drive shaft spins. Also, the hubs have less than 200 miles on them, I just replaced them, becuase the ones before stopped working.
What else could be the problem?
But, where are the auto hub vacuum lines on a 4x4 1993 IDI turbo Diesel?
It wont engage, but the front drive shaft spins. Also, the hubs have less than 200 miles on them, I just replaced them, becuase the ones before stopped working.
What else could be the problem?
Fleet Mechanic
Joined: Nov 2003
Posts: 1,372
Likes: 14
From: West Cornwall, CT
I don't believe that your hubs are vacuum actuated. The auto hubs engage (or are supposed to engage) when the front axles start turning. There is a sprang clutch in each hub that locks the driveshaft to the rotor when the axle spins.
If either of the hubs is not engaging, then you will not have 4WD. I'd check out the operation of each hub and make sure that each one locks and unlocks properly. Jack the front of the truck up enough to get both front wheels off the ground, engage the hubs by manually turning the front driveshaft. Once the hubs engage, spin each wheel by hand to make sure that the hubs disengage. The hard part of this check is getting that front end up and supported - diesels are heavy.
If the hubs are OK, then you need to look to make sure that the transfer case is engaging. Your transfer case is either an electric one, or has a floor mounted shifter. If you have the floor mounted shifter, check it by putting it into 4HI and trying to turn the front driveshaft. You should not be able to turn it if the transfer case is engaged.
Lou Braun
If either of the hubs is not engaging, then you will not have 4WD. I'd check out the operation of each hub and make sure that each one locks and unlocks properly. Jack the front of the truck up enough to get both front wheels off the ground, engage the hubs by manually turning the front driveshaft. Once the hubs engage, spin each wheel by hand to make sure that the hubs disengage. The hard part of this check is getting that front end up and supported - diesels are heavy.
If the hubs are OK, then you need to look to make sure that the transfer case is engaging. Your transfer case is either an electric one, or has a floor mounted shifter. If you have the floor mounted shifter, check it by putting it into 4HI and trying to turn the front driveshaft. You should not be able to turn it if the transfer case is engaged.
Lou Braun
