bad u joints??

First off I'm new to this forum but am excited to learn more about my truck from the thousands of other tacoma owners here on tacomaworld.

Now, onto my question. Recently I noticed a knocking noise when coasting to a stop. The slower i go the further apart the knocking noise gets. It only does it when the clutch is disengaged from the flywheel. I do not hear the knocking until I'm under 15mph since the "knocks" are far enuf apart to hear and that road noise has decrease.......I guess what I'm trying to say is that it's not very loud. From a stop, if I let out the clutch in 1st but only drive about 5mph I do not hear it, as soon as I push the clutch in I hear the knocking, but as soon as i engage the clutch again its gone. I also have noticed a slight vibration when driving on the highway at speeds above 40 and up to 60.

My thought is that my u joints might be going out. I haven't had a chance to crawl under the truck while it is in neutral and twist the driveshaft to see if there is any play in the u joints. Just wondering if anyone has had a similar issue with their tacoma, and just praying its not a transmission problem.

Also, just for reference my taco is a 98 with a v6 and it does have an OME lift (hopefully the lift has not caused this issue) Anyway, sorry for the long post but any input would be greatly appreciated.

 

i got a '98 4cyl taco. just had to do u-joints about 2 months ago, but they made a loud squeek, not a knock. and it was only when in gear and load applied to the driveshaft, so never without the clutch engaged. took me a while to figure it out. hope that helps!

 

jdbriggs, thanks for the quick reply. I actually got a chance to get under the truck today. The furthest rear u joint before the diff was a little loose. They also looked like they needed some grease so I borrowed a grease gun from work.....now the knock is gone but I'm still gonna replace the u joints. From talking to people it seems that bad u joints can give a wide variety of symptoms so it can be kinda hard to diagnose.