U-Joints

[bidibronco]

All three of my U-Joints on my rear driveshaft look quite rusty. They don't seem to be loose in any way. I have been hearing a noise from around where my rear diff is at. It's almost like a grinding vibration. Anyone ever have this problem? I'm hoping that it's not my gears back there but just the U-Joints. Any help anyone can give would be great!

@-)

 

[firelt90bronco]

what year bronco? My 90 has the same problem.

 

[mbtech2003]

possibly could be your bearings in your rearend mine went about a year ago. if it is your carrier bearings then u can do them your self with out readjusting them. if it is the pinion bearing then u need to bring it to a shop to replace

>- josh

 

[79bigbronco]

un bolt the d/shaft and turn the u joint cups with your fingers, if they move smoothly they're fine , if they are rough they're not. good luck

 

[Seabronc]

Have you ever lubricated them or the slip joint? If not they may be getting ready to fail. There should be grease fittings on the U-joint, the slip joint, and the double carden joint. The one on the double carden joint is a little difficult to get to, my favorite mechanic has a special fitting he made to do that one. Unfortunately, if the joints are starting to go, then greasing them now probably won't do much good. Why don't you drop the shaft and check the flexibility of the joints.

Good luck,

>-

 

[mbtech2003]

if the u joints are still factory then their is no greese fitings same with the slip joint though u can mark it and pull it apart to grease it thats what i did with mine. before a u-joint broke :-" now i have a new driveshaft b-(

 

[mbtech2003]

un bolt the d/shaft and turn the u joint cups with your fingers, if they move smoothly they're fine , if they are rough they're not. good luck

31743[/snapback]

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theese newer driveshafts are bolt on ****** units their is no way to just turn the cup. though u can unbolt the driveshaft and spin the ****** and the double carden joint too see if they move rough or smooth /emoticons/[email protected] 2x" width="20" height="20" />

ps. make sure u set the e-brake first and the bolts are 12mm 12point bolts. make sure u soak them in pb buster first to break up the rust first /emoticons/[email protected] 2x" width="20" height="20" />

 

[Broncoholics]

I'd pull the driveline, the u-joint at the axle end fails first, look inside the caps. I use the cone shaped greas fitting for the CV ball socket, **** it up and work it around. Its not the best but it works. While its off, check to see if the pinion nut is tight. Then check the fluid level in the pumkin. If its low you know the rear end will need looking into. Might as well check the nut on the t-case yoke as well if the shaft is off.

 

[bidibronco]

Could bad U-joints be the reason my truck is shaking? Oh... It's a '94 with the E4OD and a little bit of a built 351w... Also, does anyone know if there is a bigger axel out there that has the speed sensor in it like the stock one? @-)

 

[Broncoholics]

Sure but you might find its something else. I'd start with the driveline casue it can fail rather quickly once bad. Once all the u-joints are replaced and the slip shaft is also good (take it to a shop to know) and if the vibration is still there I'd look into the rear end. With the driveline off you can feel if rear end or t-case yokes have play in them due to a bad bearing. In/out movement isn't a problem its up/down, side to side movement thats bad.

Low fluid level in the rear end will burn up the bearings which will cause the tooth pattern to get off. This causes a vibration and will soon fail.