Not sure if this is better suited for the 4x4 section or the axle section but put it in 4x4 hoping maybe to get an answer..

I have a question for you techs or even 4wd veterans.. Ive noticed whenever I have the front hubs locked that ive been getting a vibration in the steering wheel... It feels kinda like an unbalanced steer tire.. but I dont think thats what it is. Mainly because It's smooth as glass when the hubs ARE NOT locked. Ive had it on both dry and icy/snowy slick roads seems to make no difference in the feel. First couple times I had them locked i thought it was because of the adverse road conditions but it does it even on the dry clean roads i know are smooth.

My Question is since this is my first 4wd truck.. is this normal for when the hubs are locked? Or is it a sign somethings wrong with them.. When i got the truck they were very stiff to turn the selector.. I pulled them apart to rebuild, regrease as I had been told thats what they needed because they were hard to turn.. Which did fix that problem... but ive felt that vibration even before doing that... and seems to be getting worse.. Im not 100% certain its in the hubs or if i need to look somewhere else.. Hopefully yall can point me in the right direction there..

 

I drive most of the winter with my hubs locked. With the transfer case in 2wd, there is no noticeable difference in feel until I make a sharp full lock turn, then I can hear the front U-joints complaining a little. Sounds like a problem somewhere in the front axle to me.

 

kind of my feeling there too. any chance itd be safe to assume the hub lock itself might be bad?

 

Not likely the locking hub. There's no relative movement in the locking hub assembly when it's locked, so it doesn't tend to cause any problems unless it either breaks or sticks (sticking would mean it either wouldn't lock or wouldn't unlock).

Most likely culprit would be U-joints in the front axle or front driveshaft (axle probably more likely if you're feeling it in the steering wheel). You can try to see if there is any freeplay in them, or if they seem tight, but it's not that easy to check them while they're in the axle. Removing them is a bit of a pain, but it's not rocket science.

 

i was thinking if they were "bad" maybe it was letting oneside slip or something internally.. when i pulled them apart to re-grease them after last winter they were bone dry.. and when i flip them to free they dont always release which was the other reason i was suspecting them.

Well i know the ones in the driveshaft are new so will have to check the ones in the axle then..

 

Several days after letting my youngest girl take my truck to the prom, I found one hub locked in and one free. Had driven it several days like that and did not notice anything.


We did have an interesting discussion as to why the truck had left the pavement that night...

 

lol bet that was an interesting conversation for sure...

 

Hubs will never slip. Break, maybe (if you abuse them). Stay disengaged when you want them locked, maybe. Stay engaged when you want them disengaged, even more likely. But never slip.

By the way, greasing hubs is a good way to make them stick. I don't like having then dry either, but adding grease seems to cause more problems than it solves. Keep in mind, they aren't bearings that are constantly moving against each other, they don't need a lot of lubricant. And if the grease is sticky (like it always is in the winter up north) it can keep things from sliding apart or together.

If you think they are sticking take them apart and clean most of the grease off of them. But even if they are, that won't cause the vibration you are talking about.

 

downside is i dont know how much abuse the previous owners did to the truck.. from what ive seen with the rest of the truck.. be willing to bet they werent nice to it...

when i regreased them i didnt use a ton of grease.. just enough to keep it lubed and free.. (actually followed a video made by a ford tech to make sure it was done right).. being dry and impossible to turn becomes a problem too which is what i was having before ripping them apart.. matter fact the one still feels like you have sand stuck in the mechanism when trying to turn it.. which was also the one that frequently had the selector so stiff it there were times i couldnt turn it..

 

its apparently starting to take up humming in the front end now... its starting to remind me of how the rear diff sounded when the pinion bearing went... didnt really feel any vibration on the way home today.. (not sure if thats a good or bad thing at this point...) hubs were locked and had 4wd locked in.. Hum would get a little louder every time i went to slow down... thought maybe the pumpkin leaked the gear oild out so pulled the fill plug from the hole when i got home... seems to still be "full" although none ran out the hole.. cover felt warm but the gear oil seemed really runny... (not use to that.. usually its thicker closer to like homey or something... ) took my pry bar and tried to wiggle the ujoints on the end of the shafts.. they didnt budge at all.. but the truck was sitting on the ground still and everything still locked together..

roads were still pretty sick... truck slid around a few times...

 

The most common cause of problems with the front drive axle in these trucks is dried out u-joints from lack of use, this the first step in their death and there is no way to fix the problem except to replace them. The symptoms you state describe seized joints exactly IMO.

 

darn... was looking at them tonight too and they looked like theyd be a PITA to get apart too..

 

You've got to pull the hubs/rotors off (which isn't too bad), then pull the spindles. That's where it can get fun. Getting the nuts off is a piece of cake, but getting them out of the knuckle is usually a pain due to rust. There've been a few threads with tips people have tried.

Once the spindles are off the axles slide out and replacing U-joints isn't too bad. But again, rust often makes it tough to get the caps pressed out of the yokes.

 

unfortunately Shawn, i think the guys nailed it with the bad axle u-joints.

one quick trick to try. lock the hubs but t-case in 2 wheel. go for a ride and see what it does.
then unlock the hubs and t-case in 4 high. see what it does.
if it is more noticeable in 2 wheel with hubs locked, i would look at the u-joints and front differential in the axle. if it is more noticeable with hubs unlocked in 4 wheel, i would look at the t-case.

 

shouldnt be too rusted as the dealers had them out couple times in the last 2 years... had the pass side axle housing seal leak twice.. and had them change the "dust boots" (thats what they called them on the ends of the housings) on both sides the 2nd time.

hubs locked & 2wd the steering wheel shakes going down the road like its got badly unbalanced tire...

hubs locked 4hi its smoother...

both setups instances it hums now... when 2wd and hubs not locked its quite and smooth. roads are not permissible to try with hubs unlocked atm.. theyre getting better but slowly but weathers going to turn bad again this weekend along with the beginning of next week...

didnt know you could have them unlocked and tcase in 4..