shaking/vibration
 

recently on way to work i noticed a slight vibration as i gassed it to get up to speed.... it feels like it is coming from front end but not sure. as i returned home i notice that it is getting worse....i crawled under it (91 full size bronco..5.0 efi w/e40d tranny) and pushed and pulled and tryed moving drive shaft and front axle on 4x4. the driveshaft has not up and down movement or front to back, but it does turn slightly, is this normal on broncos? could it be shocks? u-joints? tire out of ballance? any advice is greatly appreciated! at wits end .....having dominoe effect....driver side window came off track as the outside weather reached 24 degrees!!! ahh what a wonderful feeling...lol.

For the vibration, I would first start with the u-joints. Put the truck in neutral, block the wheels, and jack up the front and then the back to check the u-joints. If the vibration was happening while you were in 2wd, you only need to check the back as the front drive shaft would not have been spinning at the time. There shouldn't be any play at the u-joint itself.

ok....i climbed under the bronco and theres no play up and down of any kind, but if you try and spin it ...there is a small amount of play if you spin it back and forth. it has only done it in 2 wd but havent locked it into 4x4 yet. i just got in from work and the vibration has increased ...at around 30 mph. once you get up to around 60 the vibration is hardly noticeable ....but i can still feel it. thanks bullitt for the advice. guess ill just replace u-joints and go from there if that doesnt fix the vibration.

There is a chance you lost a balancing weight on one of your wheels. May not hurt to get them balanced again and rotated for good measure.

Shaking and pulling
 

I have a 1988 ford bronco, automatic trans.(electric 4x4 switch). I was driving and I heard a pop. Now the front end vibrates when I accelerate and it pulls to the left. I think its the differential because when I jack it up and go to take the tire off it wont rotate. So I guess the differential is locked like its in 4-wheel. Im not good with differentials, all I know is they are automatic lockers, the differentials are original(old as SH!T), and the axle, brakes(whole assembly), and hub, shocks, and spring are fine. Any feedback will be much apperciated.

May be a bearing that has gone bad and now is turning hard.

Are both front wheels acting like that, or just one? Were you in 4wd at the time? If not, it's most likely not the differential.

Its only the front driver tire thats doing it. And it wasnt in 4wd. So probly bearing or something huh?

I would lean toward that. It's a good place to start.

thanx for the advice man. Turns out my paliper broke and the brake pad got stuck. Thanx though