Rumble strip, washboard like vibration with deceleration

'05, 105K miles, manual trans, and in the last week or so it's developed a humming, rumble-strip, washboard-like vibration in the front end. I'm suspecting a wheel bearing, but thought I'd run this past you guys before I either tackle it myself or send it off to the doc's.

1. Seems to be worse when cold
2. Vibration initially so extreme as I rolled up to a turn lane (4-8mph?) that you could visually see the hood/body shaking, but severity has much decreased since then.
3. Especially evident when decreasing speed/coasting to a stop, but hums between 55-60mph as well, and varying other maintained speeds. Not so much with acceleration.
4. Vibration rate decreases as speed decreases.
5. Vibration is NOT evident in pedals/wheel so much as definitely feeling it in the seat/floor.
6. Clutch in or out, in gear or out, doesn't matter.
7. New tires in Oct of '18, returned immediately for a recheck when I had a front end shimmy; they claimed a bent rim, but once the tires were re-balanced I did not have any further issues.
8. Lugs are all accounted for & tight, new Dunlops don't seem to have any broken belts; don't think I'd experience the kind of initial violent vibration from a bad tire.
9. New shocks & bumper in Nov '16, but have had zero issues since that install (until now).
10. Changed trans & diff fluids in summer of '16.

That's about all I can think of to include. I've got a friend coming over tomorrow to jack up the front and get the wheels off, but have no idea what I should be looking for or how I would even know if a wheel bearing looks bad?

Thanks much for any direction!

 

You are in Il. Do you have a build up of snow/ice inside the rims? Doesn't hurt to look. Also have the drive shaft u-joints checked. They will vibrate bad when worn out.

 

Grab the front tires at 10 & 2 o’clock and push and pull HARD inward and outward. If you feel any clunking or play your wb needs attention.

Check your driveshaft / ujoints

Any change forward vs reverse?

 

link a video if you can

 

Check your carrier bearing too. (Center of driveshaft)

Sometimes when the rubber around them wears out on a manual car (more evident) the bearing will rattle around in there and vibrate a lot)

 

Good call.

Not to be a stickler but this is called a center support bearing. Carrier bearings are on the carrier, a differential component.

 

All good, I never mind being corrected. Makes sense, not sure why but I’ve always called it the driveshaft carrier bearing, but often abbreviated it on forums as CSB = center support bearing. Never noticed I did that til now haha!

Op, listen to that dude, driveshaft center support bearing, check it out. I had very similar symptoms on my e36 M3 and my MKIII Supra when the center support bearings were torn up.

 

I had a u-joint and center support bearing crap out on my manual Taco. Only had serious vibrations/banging during acceleration from a dead stop.

I was going to suggest a loose wheel, but he's already checked that.

 

Wow, guys, thanks so much for the tips. I keep my truck undercarriage pretty clean in the winter with regular car washes, so no buildup of any snow/ice.

Will check the U-joint, center support bearing and yank HARD on the wheels (I'm assuming while on the ground, and *not* jacked up?) at 10 & 2.

I really wish I had thought to capture that initial hella vibration when it was extreme. It seems really unusual that it's slacked off in severity, so whatever it is wants to lull me into a false sense of security or something...

Anyway, thanks again for the direction, I feel like we should be able to pinpoint something tomorrow afternoon. You guys rock!

Edit to add: I neglected to mention that there is no 'clunking' or noise when reversing or accelerating from a stop. I honestly haven't checked to see if it still vibrates when decelerating when reversing at speed... Maybe I'll try that tomorrow.

 

It stopped after rebalanced? Have them do hub centric Road Force balance.

 

Actually, now that I’m thinking more about how I do it, I probably grab the tire more at 12 o’clock for the wheel bearing check

 

The non-balanced 'shimmy' wobble feels totally different than what's going on now. It was, initially, pretty violent and only happens at low, deceleration, nor am I feeling it in the wheel like it was before I took it back for them to re-balance the tires...? In my gut I don't think it's the same thing, but I certainly could be wrong.

 

Pretty sure this is the needle bearing on the drivers side CV axle. I'm going to have a ECGS bushing installed in the next couple of weeks myself.

If you put it in 4x4, and the "vibration" stops, then this is definitely the issue.

 

The way the hood/body shook, I would have thought it would be in the front as well. But we're getting ready to tackle the job now and my mech friend has had me *back* into the garage. He says that since I'm not feeling vibration in the wheel or pedals, that it is probably in the rear, that this is 'the rule'. He used to do this for a living, so he would know! I understand that rear wheel bearing are a massive pain in the ass to fix, and if that's the case, it's going to a shop to be done. My friend is too old to be cutting off axles (?! dunno if that's the case with Tacoma, god forbid, but that's what he says) to fix shit like that.

 

Any smell outside the vehicle after rumbling to a stop? Not too great with cars but had a similar experience in our CRV. Turned out to be a sticking/stuck brake caliper.

 

This happen when you brake or just the truck gradually stop?

 

Following

 

Okay, after jacking up the rear and much shaking and turning of tires, it's been determined with a fair degree of certainty that it's a transfer case output shaft bearing. Wheels are solid and the u-joints are solid at all points along the driveshaft, but where it makes the connection to the transmission, as pictured in this thread here, there is a fair amount of rattle; easily as much as 1/8". Turning the rear tires also generates noise at this point.

For the few threads I was able to turn up on this subject, vibration is a common symptom, but this one is the most concerning. Is it really that difficult to replace bearings at this point? Is a transmission replacement/rebuild the only solution to this issue, or am I misreading this entirely? Trying to find the procedure in the online service manual, just to see how involved it is, is proving to be elusive, but I'm still looking.

At any rate, obviously this is going to the shop on Monday, but I'm more than a little concerned I can't find many others posting about this here, or I'm not using the right search terms...

 

I wanted ya'll to know that I got my truck back last Weds and it turned out to be the rearmost u-joint that was causing the problem. The play at the output shaft was apparently within specs. At any rate, no more washboard vibration when slowing down or humming at high speeds. At least I'll have a better idea of where to point the finger if something similar happens again. Thanks again much for all you guys' input!

 

What did you to to fix the rear most ujoint? Replace or re-torque? I feel like I have a similar washboard type vibration when slowing down and intermittently at other times.