Vacuum diagram 4x4 locking hubs 2004 f 150 4x4

SOURCE: 1998 ford ranger 4x4 Front Axle hubs will not engage

I found a website that explaned that you can remove the hub and dust cover, inside is a spring which holds the hub out, removing this spring and replacing the rubber dust cover and hub will lock your front hubs in continious. as is done on later models, This has worked for my 98 4wd

SOURCE: 1986 K5 Blazer front hub/axle problem

3 bolts from the back, axle nut and take the caliper off pretty easy.

SOURCE: banging noise in 4 wheel drive under torque. front hub questions.

Hello scotch1812, those of us that still enjoy the square headlights have to stick together! The front axle in our YJ's are dana 30 with a high pinion! The high pinion make the ring and pinion spin in a reverse rotation from the dana 30 found in CJ and TJ Jeeps. When Chrysler designed the YJ front axle, they removed the manual hubs like those found in CJ models and installed a vacuum disconnect on the passenger side axle shaft. The passenger side axle shaft is 2 piece with a sleeve that is moved into place to connect the 2 pieces of axle shaft when you shift the transfer case into 4 wheel drive. This is done via a vacuum module mounted on the axle housing. If your module diaphram goes bad you have no 4WD! If your vacuum hose comes off of the module or breaks you have no 4WD. Now when your transfer case is in 2WD the front driveshaft does not turn. The vacuum disconnect allows this to happen. As for the hubs, they are simply hubs with sealed bearings and a universal joint to allow your front wheels to turn left and right. If you hear the banging noise in 2WD it could be a bad universal joint in one of your axle shafts.

Now if you are hearing the banging noise only when you are in 4WD there could be a number of reasons. You could have a broken axle shaft or a bad bearing in your ring and pinion. Your front driveshaft could be bent or at least not straight. I would start with the driveshaft. Just lay under the Jeep (Not running! With emergency brake set!) and spin the front driveshaft. If it spins true and doesn't have an out of round rotation we can rule that out! Also, grab it and push it and pull it to check to see if your universal joints in the drive shaft are gor and tight! They can make a grinding noise or popping noise if they are bad!

Try these and let me know what you find! We will find your problem!

map6260

Doug Crawford

• 63 Answers
• Posted on Jun 22, 2009

SOURCE: 98 Ford F150 4x4 wont engage

I copied something that you might use because it was handy I know its not going to be exactly for you but it might get you fixed. Let me know if it helps or NOT please. gl dc

SOURCE: front hubs dont lock when put in 4x4

Probably a vacuum leak. Tranny has to be in Neutral to shift into 4 low, but should be able to shift into 4 high in any gear. The auto locking hubs work off of a vacuum, if there's a leak in the line, they won't engage. If the 4x4 light is on, but the wheels aren't pulling, that's most likely the problem.