Rear driveshaft u joints

[Kane]

If kind of figured that these u joints cause many explorers to vibrate or shake how can i see or find out if mine have gone out do i have to use a jack or lift my truck to see or what is the process????HELP!!!!!

 

[Jim Galloway]

You can just slide under your truck while it is in gear and try to move your drive shaft around. If you have excessive play in the joints, they need to be replaced. The drive shaft is really heavy, so don't be afraid to put some muscle into it. Try torqueing it and moving up and down. Do it when your car is cool though so you don't burn yourself on the exhaust!

 

[Kane]

Thanks

thanks gall,but i sure dont know much of mechanical work can you please let me know where exactly are these u joints located at??

 

[Jim Galloway]

Kane,

Find your drive shaft (the long cylindrical shaft that connects your transfer case (or transmission) to your rear differential (the big round pumpkin directly in the middle of your rear axle)). Now, your rear U-joint is located where the drive shaft meets the differential and it allows the drive shaft to spin at different angle to the differential. If you have a 4x4 there will also be a u-joint at the front of the drive shaft where it meets the transfer case. Grab the drive shaft near each of these u-joints while your car is in gear or in Park and try to move it in any and all directions and try to turn it also. There should not be play or looseness in the actual joint, although the flange that it is bolted on to may turn a bit. Good luck!