4 wheel drive wont engauge

[maui]

Hello boys,

Got a question I have an 06 f350 diesel noticed that the auto lock in for the 4x4 wont engauge unless I lock the hubs the light comes on but nothing happens.
and as far as 4 low goes it takes a long time to get the truck to go into 4 low any ideas?

Also I noticed that my front axle outer dust seals were not seated how important are those seals do I need to change them right away?

[Lilpooh]

Sounds like you have a vacuum leak, usually the hub seals go bad, but you also need to check all the vacuum lines for cracks.

Usually if it's a vacuum leak, when you go to use your HVAC, the air/heat will only come out of the defrost.

[maui]

Yes The vacume line was not on all the way but even after i reseated it I didn't work but thx for the advice