01 Vibration under a load ?!?!?!

[1800AskMatt]

Hello everyone!

My 01 4runner SR5 2wd 3.4 w/ auto, has developed a vibration under acceleration pretty much at any rpm.

It started after I towed an empty tow dolly back to U-Haul for a friend. The dolly road like a jumping bean the whole way. (and I understand they smooth out with a car on them )

Now my truck feels like it vibrates the whole frame after 5-7 mph and up.

I pulled onto the main street this morning and rolled back a little on the incline and something "popped" under the drivers side floor board and then rattled for a few seconds, then stopped all together.

The vibration will go away for about 30 seconds every once in awhile.

I can feel the "vib" in the floor board and the gas pedal along with the shifter.

The "vib" causes a droning hum to the entire inside of the truck almost like driving on the rumble strips on the right side of the road that wake you up if your veering off, but not violent shaking.

The truck doesn't shake like like wheel balance. I had them done 2 weeks ago with the alignment after my suspension lift and wheel spacers.

If I shift into "N" the "vib" tames down and the cab of the truck gets quieter.

Then put it back in "D" and it does it again in about 5-10 seconds.

The steering wheel is smooth and going down hill with no load, make less vibration until you accelerate again.

My trans fluid looks good and doesn't smell and is at the proper level.

No leaks showing.

All heat shields look to be tight and so do the motor and transmission mount.

Universal joint feel tight and look fine.

ANY SUGGESTION?

Any would be VERY helpful as I am scared it is my torque converter getting ready to go.

Thanks in advance!

:zoom:

 

[Charlee78]

I would remove the rear drive shaft at the diff. and check the u joint, it might not be loose but it might be seezing. I would also check the weights on the drive shaft to see if you lost one.

 

[toytech76]

Hopefully your flexplate didnt develope a crack

 

[Charlee78]

Usually, a broken flexplate does a lot of noise ??

 

[texas_runner]

i believe it might have been a u-joint issue. I had a similar problem

 

[RichardLee]

In high school I drove my Mustang through a ditch to get out of a party, and after that it acted the same way. If I remember right, I ended up having to replace the rear end. It would vibrate and rumble that same way under acceleration.

 

[Cbpcop06]

Went through the same problem - replaced the rear u-joint and the problem was solved - until the front one gave up the ghost about a year later. Took some very close visual inspection to see the damage to the first one. The second one failed quite badly all at once and I had to take the drive shaft to a specialist and have a new yolk welded on and a replacement tailshaft purchased for the tranny. Don't let it go on too long. :nono:

 

[peter78]

It sounds a lot like when my 2001 had the univeral joint go out. I am curious why you think it is OK. I would think the joint will look tight, but under stress it will make that noise. By the way, my dealer said I should replace the whole drive shaft. I balked, but they said it was needed. I was out $800. :wtf: