My Truck : 99 4runner sr5 4wd v6. standard trans. Everything on truck is stock.

Recently started hearing and having a vibration around 60mph, and has gotten louder over the last few days this weekend. Now it starts at about 55 and will stop above 71mph. If i let off the gas while the truck is still and gear the vibrations immediately stop, but if i clutch out and coast at same speeds the vibrations are still just as loud. It seems to be coming from center right under the driver and passenger and frontwards of that. I thought maybe U joints, and may still be wrong , but those seem to be snug and fit tight. I've greased all the joints and checked the fluids and they are full. Im really not sure what to check next, ive read a few threads after searching but most seem to be having the problem when letting off the gas, which is a little dif and confusing , at least to me. LOL. Any advice would be greatly appreciated. :-) Also let me know if you need any more info, ive tried to include everything that i know about the problem and the truck...

 

Mine had a similar noise and would vibrate the whole truck, except it wouldn't go away when letting off the throttle. New u-joints and balancing the driveshaft fixed it.

 

Mine done that turned out it was a u-joint , couldn't tell just by looking at them or trying to move by hand , I had to pull the drive shaft to see it . Replaced the faulty u-joint and now that vibration is gone . Done just like yours does and would go away when you let off the gas pedal

 

Is the noise still there at 'a good throttle'? Any bit more than just very very light throttle, and the noise would be drowned out by the exhaust. It sounds somewhat like a stick in a fan....

 

Had this exact same problem, took it to my mechanic and there was a chunk missing from my u-joint. I would say eliminate that possibility before going after others.

 

my new-to-me 86 just had the same thing. u-joints looked and felt perfect, I even check after driving a while to feel if any were hot, nope cool and tight. took the shaft down and the rear joint moved easily in one direction, but very stiff in the other. I almost couln't even move it by hand. replaced it and the 2 stiff joints had burnt bearings inside and rust. $20 later, vibration gone. I'll admit it looked fine. It's easy just to drop the shaft at the dif and feel the joint to see if it's free. I'd check it.

 

Thanks for all the responses, just got back from a week of work. I got an estimate for 300 to replace the front and rear . Is this in the ball park? Also, how difficult of a job would this be for someone with minimal mechanic experience.

 

How hard is the pressing in and out part of the u joints?

 

Not hard at all. First time for me took a little while. Plenty of youtube vids on it. Hammer, socket, and a vice will do.

 

I may give it a shot tomorrow. a guy at work told me a 17 mm socket works great, then said wait....does that year model have to be pressed out / in? LOL.

 

You'll be fine. I have a 99 tacoma, built on the same line so if I could do it, you can. Oh I just got this info on my thread. I messed up when I replaced mine. Make sure you mark where the zert fitting is on the u-joint and place the new u-joints fitting in that area. I put mine in the wrong spot and I can not get to it to grease it.

 

hopefully marking in relation to both forks will put me back where i need to be with the new one. I'm getting started this morning on it , hopefully it all goes well. Thanks for all the input every 1 :-)

 

Problem fixed , rear u joint was shot. Just got back from town and no more vibes or rumblings. I have 230k miles and hoping to get many many more out of my 4runner. Thanks for all the advice.

 

update: just got back from the dealership - 1.5 hours of labor and a new ujoint - 218 out the door. noise gone. ~140k miles and the noise is gone. It sounded like a stick in bike spokes or fan blades at realllllly light throttle. nothing when no throttle and nothing at any more than 'big toe' throttle. noise could be present and then putting it into neutral would remove the noise. so much happier... now only for the ARB locker and some tundra brakes