4wd problem

[vondy09]

Hey guys im sure you are tired of getting threads on 4wd problems i read all the other posts on 4wd problems but i couldnt really find anything that answered my problem.

On my 94 xlt I hear popping noise on the drivers side front when engaged in 4wd it pops when the road is ruff or if i hit a bump. i put a new u joint on the drivers side and i know the hubs are good. is there a chance that the u joint on the passenger side can also be bad even though its popping on the driver side. the four wheel driver works but the popping is really loud and it sounds horrible.. any ideas on what it might be

 

[MrShorty]

Are you sure it's in the front drivetrain and not the front suspension?? What you describe sounds to me a lot like bad radius arm bushings or something else loose in the suspension.

 

[Willard]

you should also check the u-joints in the front drive shaft. It is right under the driver, so you should be able to hear it well.

 

[vondy09]

it doesnt make noise when im in 2wd.. i checked the front drive shaft u joints and they are good.


i also forgot to mention somes the switch light for 4x4 low turns on by itself (only on the switch not on the dash)when its on and im slowing down from 45-50mph down to zero it makes a whining sound then when i take off it doesnt make the noise

 

[DeRocha]

You mentioned the hubs are good.. How did you check them? Are they auto or manual, and how much grease was in them last time you had them off?

From time to time (especially in colder weather <30F) the 4x4 dash buttons will half illuminate. I am definitely NOT in 4x4, but assume the system is receiving a stray signal. If I engage 4x4 and then disengage it the light will go out..

 

[vondy09]

they are auto. the hubs are springy and there is no wear they didnt have much grease in them but i cleaned them with brake clean and soaked them in atf.

 

[DeRocha]

they are auto. the hubs are springy and there is no wear they didnt have much grease in them but i cleaned them with brake clean and soaked them in atf.

Once your autohubs have locked and you disengage 4x4 (but don't reverse direction and unlock the hubs) is the sound better or worse?

Even though you cleaned the hubs they are still suspect. A quick test would be to swap the driver's hub to the passenger side and see if the noise goes with it..

 

[vondy09]

there isnt a noise when i disengage 4x4

 

[DeRocha]

there isnt a noise when i disengage 4x4

That points to a hub problem or problem within the differential (broken axle shaft). But because the problem goes away when you disengage 4x4 it would point to a HUB problem. Generally axle shafts don't brake unless your are hard on them (mainly hard off-roading). If you did have a broken shaft then I would expect the hub would have a very difficult time locking as the axle would most likely not rotate. To check for a broken axle problem you can engage 4x4 which should lock the Hubs.. Securely Jack up the driver's front tire and then try and rotate the axle shaft by hand.. Repeat the same on the passenger's side.