Trying to diagnose a pulsing driveline vibration

I have a 2003 Tacoma 4x4 with the 3.4 and a 5-speed tranny. I am getting a pulsing vibration. Its not constant, its more like womp womp womp womp. It can be felt the most between 25-30 mph but you can feel it slightly up to around 50 mph. I had a mechanic say it was probably the carrier bearing in the center of the rear driveshaft but I want to make sure before I shell out $ to buy the bearing. I crawled up under the truck and tried to shake the drive shaft but it won't budge at all. It is solid with absolutely no movement in it. Also the rubber around the bearing is solid meaning you can't push on it and make it move. Could this be the problem? I know they are supposed to have some movement in them but mine has none like it is froze in place. Also while under there I noticed the u-joints are throwing grease all up on the underbody of the truck. Could they possibly be worn out? Everything is original on the truck with 92,000 miles on it. Any imput would be appriciated, Thanks!

 

Hit all the grease fittings along the drive shaft, etc... Maybe not fix the issue but I always say, trouble shoot from simple to complex. Besides it wont hurt. Jacking the rear tires up and putting truck in neutral (blocks on front tires) allows you to rotate the drive shaft for ease of access to the grease bearings.

Here's more info:
http://www.4x4wire.com/toyota/maintenance/front_end/lube/

That said, where is the noise comming from? It could also be a wheel bearing but 92,000 miles is pretty premature for that...

 

Yes. You want to see grease slinging from the U-joints. That means someone greased it. Hit them again.

The (CCB) center carrier bearing is probably the problem. My vote is on the CCB.

Also, you could have a flat-spotted tire. That's what is causing my womp-womp at the moment. I just don't want to shell out $600 for tires yet.

 

Did you take it out of gear when you did this? If not, it will not budge do to the load still on it. Make sure you pull the e-brake, and put it in Neutral when checking anything with the driveline.

 

Thanks for the reply's guys, Wouldn't a wheel bearing be a 24/7 thing? This is intermittent.

Tires are all brand new with 4,000 miles on them, I will go ahead and grease the driveshaft again. If it is the CCB would it be best to replace with a toyota bearing or is there another bearing that guys are having luck with? I know the toyota bearing is $210

 

When I did this the e-brake was pulled and tranny in neutral.

 

Probably... Truth is, without a lift/big tires, neither CB or WB should be going bad at 92k miles .

Hit it with grease and see how that works...

Any more info would be good though. Is it just a noise? Is there lurching, shaking, etc...? Generally a bad CB has some shimmying in the drive train. Maybe you can get a recording of the sound. And if you have a go-pro (or a local TW member) you can mount it under the chassis to get a look of what is going on while driving.

 

Is the womp womp womp when you are accelerating? Or only when you let off the accelerator? Does it change when you put the lever in neutral and coast along?

 

There isn't really any shaking or anything. But you more so feel it in the truck than hear it. You can feel the vibration in the truck but its not in the steering or floorboard or anything. Thats why I haven't been able to pin point it yet..

When accelerating it is most present. if you let off the gas it is still there but it is very minimal, same if you hold the clutch in or put it in neutral with the cluch out and coast it is there but very minimal but can still be felt.

 

u joint starting to go or center support bearing, it could be your tires too, what kind of tires, it mud and snow types, then it could be the tread making the noise, usually you can see the wearing on the tires if it is that bad..

 

The tires are brand new firestone destination LT2 with a little over 4,000 miles on them. One thing I should mention, reason I think it has nothing to do with the tires is because once you drive around for a while the vibration is minimized. Like once whatever it is warms up it has less friction. The colder the worse the vibration when you first take off in the morning.

 

I think this eliminates anything trans or engine related. However, still could be 3rd member pinion bearing, carrier bearings or axle bearings.

Does the repetition rate of the womp womp change with speed?

 

How often do you drive the truck.

 

I drive the truck everyday about 40 miles or so. The rate of pulsing is always about the same. Like I said you can mainly only feel it between 25-30 mph. Maybe a hint at any speed above that til around 45 but It doesn't vibrate enough where I can honestly say it is there. Also if I am driving and it is vibrating I can hit the 4x4 button and when it locks in the vibe is gone. as soon as I click the button and you hear it lock out the vibe is back but slightly worse than before until I come to a complete stop. My mechanic said it was probably taking the pressure off the carrier (still assuming it is a bad CCB) when it was locked in 4x4 because the front wheels had the drive pressure now instead of the rears.

 

Similar to a vibration I had last summer. It was the carrier bearing. I bought a cheap $25-30 one just to be sure instead of going for toyota $170 one. If you change it, make sure you put everything back in line. I made that mistake and driveshafts were out of phase.

 

Im thinking this. Probably was never greased since buying it . If the grease eliminates or reduces the sound/vibration, you can bet your ass its one of you u joints.

 

Thanks for helping me try to diagnose this guys. I'll try greasing the U joints and see what I come up with! It didn't have the vibe when I bought it in July... maybe they greased it before I got it to hide the vibration? But I will try that first!

 

I have a 95 2.7L 4x4 reg cab, 5 sp. Mine does this same thing. I've been trying to figure out how to put it in words. I don't have a carrier bearing. It's done it since I bought it. I have greased everything. The u joints have no play. The PO replaced the clutch 2 weeks before I bought it. Just like the OP here, I feel it only in my seat. I would add that is "almost" feels like a very slight resistance like applying the break lightly. But very subtle.
I only feel it while under acceleration or cruising speed. If I am costing like say down a hill, it's not there. Up hill though it's there. If I push in the clutch while it's doing it, it goes away.
I don't have an loose bearings in the rear end. Using a pry bar to pull up on the tire while up jack stands. There is no growling or resistance while spinning the tires by hand.
I am going to replace all three u joints on the rear drive shaft this spring and replace the fluids in the tranny, diff and axles.

 

Mkatts, You situation sounds to be a little different than mine, whenever I coast or push the clutch in my womp womp vibration is still there..

On another note I greased every fitting under the truck this evening and took it for a ride, still there just like before. I'm leaning toward the carrier bearing now. Ill check out the u joints when I do the job. Do you guys think I should go ahead and replace all three with 92,000 miles on the clock?

 

Its really hard to say. Nothing should be failing at 92k and I wouldn't want you to waist money on an assumption. Nothing seems to be in danger of catastrophically failing so maybe more troubleshooting is in order? Try mounting a go pro under the truck and see if there is play in the bearing. If you don't have one, check in the local threads to see if you can borrow one. You can also do a drive by an see if someone can hear it better from the outside and get a better idea of where the sound is coming from (can also put someone in the bed of the truck while you are driving.... carefully).