Driveline Vibration

I've noticed an intermittent driveline vibration. It lasts 2-3 seconds at a time. It feels almost like I'm driving over a rumble strip (but less severe) and seems to be coming from somewhere on the front half underneath the vehicle. I am not sure, but maybe it occurs only during light acceleration and not during coasting or deceleration (again, I haven't confirmed this yet.)

Ideas?

 

Lifted?

Does it go away in 4hi?

 

Maybe Torque converter shudder?

 

His profile says MT.

But that doesn't mean that's correct.

 

Usual suspects...Ujoints, carrier bearing?

 

Oh..didn’t see that

 

Always a good place to start:

https://www.tacomaworld.com/threads/drive-shaft-vibrations-solved-step-by-step.244535/

 

Man, I'd be really disappointed if that were causing it considering I was told it's an MT That would mean I've been shifting for nothing

 

Maybe you’re a candidate for anECGS bushing.

 

I’m not familiar with this. What is it?

 

More info… when I pulled out of my parking spot this morning, there was a “grinding” or vibration from underneath. If I could guess as to its exact location, I’d say directly underneath the center console, pretty close to immediately aft of tranny. I crept along at about 4-5 mph with windows down listening to it. The vibration intensity was rhythmic, varying frequency with vehicle speed. It was independent of load and did not change with clutch or gear engagement.

I’ll also mention that the frequency of the vibration “intensity oscillation” was in the neighborhood of 1hz which pretty well correlates to the driveshaft rotation at that speed. I would suspect a more constant intensity NVH from the carrier bearing. So… u-joint?

I’ve had a few too many jack and cokes so maybe this last bit is useless but when I say “intensity oscillation” I mean it sounded something like this: ggghhhghGGGHGHHGggghhhghGGGHGHHGggghhhghGGGHGHHGggghhhghGGGHGHHG

 

You can check the carrier bearing just by getting under there and trying to move it with your hand while the vehicle is off, when they're bad you'll be able to tell, IMO anything 1/2" of movement or more is excessive and it should be replaced. If the u-joints are bad you should be able to see that in most cases also, sometimes you have to jack it up to get all the tension off the driveshaft.

Another thing to know, if you go in to do the carrier or the u-joints you should do both, if it's coming apart, fix all the wear items on the driveshaft. It's not something you want to do again if you can avoid it.

 

Thoughts? I’ve read that some free play is normal. I don’t have any experience to draw on but it seems excessive. I don’t notice any play in the u joints when trying to shake them around by hand.
https://youtube.com/shorts/FZasQ1doGyg?si=f3zpnGi6OpcYnu15

 

I'm sure there's a spec for the freeplay. My carrier brg didn't cause any vibrations and it was noticeably worse then that one. It caused a clunk felt through the chassis when first starting off, the feeling was like drivetrain taking up slack

 

Just had this issue 2 months ago. Had to replace carrier bearing, u-joints and... drive shaft as the slip joint was worn out. But, it now runs smooth as silk. Hopefully you won't have to replace the drive shaft $$$

 

So you replaced them all at once?

 

A bushing that replaces the roller bearing where your CV slides into the diff. Usually the noise is more of a growl, I did mine and it smoothed out the truck even though the bearing looked good when I pulled it. If you are lifted it's not a bad thing to do.

 

No. We did the carrier bearing (which was completely worn out) and U-joints first. Vibration got worse with new tight components. Drive shaft was last and fixed vibration.