I have a '99 Ram 1500, 318, 4x4. I am having issues with the 4 wheel drive either not engaging right away or staying engaged well beyond me putting it in 2WD on the floor. I drive it to work this morning and it took about 12 of my 15 mile drive before it actually engaged and about 7 miles on the way home before it disengaged. I believe my vacuum lines are freezing up somewhere, does anyone know of a good fix for this? My local auto parts guy suggested putting some air brake antifreeze & conditioner into the vacuum lines. Is there something better? Where should i put it in at?

 

Have you checked the lines to see if they are cracked/split, etc? Assuming the temps are below freezing, does it do the same thing when the temps are above freezing?

 

When mine did that, I parked it in the garage with the torpedo heater pointed at the lines, and let it run for an hour or so, to thaw them out. Then I blew them out with compressed air. No problems after that.

 

Jkeaton, I have not checked they lines recently but when its not freezing I have no issues

 

You could also put in a Posi-lok (locks the two axle shafts together via a cable vs. the vacuum system you have now) or a Perm-lok (permanently connects the two axle shafts and essentially does away with the CAD function) part #1100. The Perm-lok is like having a solid one piece axle on the long side instead of two shafts, and your hubs are locked in all the time.

http://4x4posi-lok.com/app_dodge.html

I've got the Perm-lok in my Dodge Ram 1500, and have been very happy with it. When I put it in 4WD, I know the front axle is engaged.

When you think about it, Jeep ZJs, TJs, and the new JK and JKU Wranglers all do not have a CAD, and have unit bearing front hubs like our Rams (essentially hubs locked in all the time).

 

Is that any harder on the tires?

 

Might reduce your gas mileage by a point, or so.....