Noisy U-Joint-- How to tell?

[Gavin Allan]

I have a low frequency rumble with a minor vibration. I am sure it is a work out universal joint (because I had the same symptoms with a previous Ranger). How do you tell which joint is worn out? Can you shake them and see play in them? Do you have to disconnect the driveshaft and put them through their range of motion to find the worn out one with resistance/play?



I know how to replace them-- it is identifying which one to replace (before it blows up) is what I am asking here.



Thanks

 

[Michael Cacioppo]

Bad universals will have too much play even while attached. Test the amount of free lash that you get when twisting shaft back and forth. There should not be any play in the U-joint. There will be some lash in the gears (tranny tail shaft or Ring & pinion) but not in the joint itself.