Hey guys, well I replaced the stock air filter with a K&N filter yesterday. This morning I notice that my 4 wheel drive is not engaging. I had gotten in the habit of tryng to engage my 4 wheel Hi about onced a month when going offroad. Today it never would engage when twisting the ****. Any idea what's wrong?? I hardly think that I messed something up when installing my new air filter. Any idea's what it could be??? Also, my check supsension light has came on a time or two in the past three months or so. Please help!!

 

This may be a stupid question, but did you check to see if the truck really was in 4 wheel drive and just the indicator wasn't working?

 

Yes. I can usually hear it engaging, and I hear absolutely nothing. And I can tell it's not engaged when turning/driving...

 

This happened to my f150 4x4. The vacum solenoid lines were corroded because they are running underneath the battery with the acid causing them to break. The lines colors are pink and light blue, not sure which one is which. My mechinac fix it for me. Hope this helps