Okay this is on my mom's 4runner, i was driving it to work today since mine is in the shop and when it gets above 55mph when you give it gas there is a vibration. This only happens at 55mph and above and only when on the throttle.

Here is some specs on the 4runner:

1999 limited 4runner
156,xxx miles
2wd, Auto trans.



There is also a sort of "clunk" when it is shifted into gear. Which is makeing me think a u-joint is bad. What do you guys think

Wouldn't a bad u-joint/s cause a clunk when switching it into gear and wouldn't it also possibily cause this vibration?


Thanks again guys!

 

I've got the same problem on my 92 with manual trans. I am also leaning towards u-joints. Not sure though...

 

Well thats what i was thinking. Not sure how to really tell or how to replace them for that matter

 

Grab the drive shaft and rotate it, check for play. You may not be able to tell but if it move at all (not the whole yoke that is play in the diff gear) but just the shaft, then there is your problem. My just need some grease, this can fix a small vibration.

 

well idk if it is because of the 2wd model, but there is no zurks on the u-joints.

To test it on an auto transmission, does it need to be in neurtal or drive or park?

 

You could try jacking it up to get the weight off of it. Put it in neutral and crawl under it and play with the driveshaft.Wiggle it, turn it back and forth paying attention to the joints there shouldnt be any slop inthe joints. It does sound like ujoints tho.
156k on 2wd ujoint doesnt seem like much but you never know.

 

Alright, will try replacing them then!

Probably replace both and not worry about it. I know i will get blamed for having them go out since ive driven it the last two days , so i better just pick them up on the way home!

 

Just to let all of you know, i bought two u-joints on the way home just in case both of them were bad.

Got home pulled the driveshaft and it was indeed the rear u-joint.

It has very limited motion, the front feels okay, so i am going to return the other one and get my $25 dollars back. Btw i would replace both now, but i cant really afford to if one is not bad. Ill have my mom pay for the other one next time, since it is her truck and fix it later.

Just for all of you guys that might have the same problems, I tried wiggling it while it was on the ground and couldn't tell. Just like DBCX said, once i put the rear end on jackstands i could tell a slight difference. But i couldn't really tell which one it was until i took the driveshaft out, but you might be able to tell without pulling the driveshaft. Once pulling the driveshaft, it is obvious it is the rear u-joint causing the problems

Thanks again guys!


"Good Night and Good luck"