New washboard ride?

Here's a video:
Where the seat is shaking violently is where Im getting the bouncing in the truck. As soon as it stops the bouncing goes away as does the shaking, minus any bumps I hit.
https://carousel.dropbox.com/photos/cc/DD2eFQVtVRerB6W


Ive had a bumpy ride in my tacoma since I got it... its a truck. But I did think it would ride better with the TX Baja shocks... oh well.

Recently my truck has developed a very noticeable washboard ride in the rear. Ive noticed a lot of bed bounce especially when this happens.

To be honest, it feels like the tail of the truck is bouncing up and down on a smooth washboard, can go on for 15-30 seconds of highway driving.

Ive driven the same road to and from work for the past 5 months, and this is new to me. If the road was a washboard, I would feel it.

Where should I begin looking?

 

When was the last time you had your tires balanced?

 

What tire pressures are you running?

 

Tires have 24k miles on them. I was going to have Toyota balance them when I drop it off for my last freebie oil change.

Tires are at the factory pressure, which I think is 45 on the AT's? I always have them at that pressure and this just developed recently.

I've bought new AAL springs (wheelers progressive) to remove my +1 spring on the rear to smooth the ride out, but wanted to try and figure this out first (and get my last free oil change lol)

 

Tire pressure is supposed to be 32 psi. Your ride sucks because the tits are over inflated.

 

I thought over inflated tits was a good thing

 

X2. Let some air out.

 

32 psi front
29 psi rear

no need to run 35+ psi

 

Ride can suck when those are over inflated too. Lol.

 

Even still. This change in ride has changed in the past 5k miles.

Factory TA KO's

 

Can you feel it at all speeds? Or only at certain speeds? My initial thought is you lost a wheel weight or two and need a rebalance

 

Oh nvm. You have the tires that came on the baja.

Check the torque on the leafs

 

The washboarding is at random speeds, but most common between 50-70mph. I was able to grab a video yesterday showing the passenger seat shaking... but it wasn't the normal bumpy road shake. As soon as I upload it Ill post it.

I did let some air out of my back tires just to see, down to 38lbs. Rides smoother, but the washboarding is still there.

 

Agree that you have tire pressure set too high. Reduce both fronts and rears to 35 psi. However, tire pressure does not usually cause vibration. You need to have the balance checked, and while the tires and wheels are off the truck, check the tires for separation, bubbles, whatever. What you describe sounds like tires out of balance.

 

Sounds like the vibration you get when your differential is out of spec due to a lift. I had the same thing happen on a lift when I didn't install the shims.

Now if you haven't lifted your truck check the carrier bearing. It thinks that's what's called. Holds the two piece drive shaft. I've heard of those things going bad. I also know a lot of guys use spacers on it to correct the driveshaft angle on lifted trucks. I personally prefer the shims.

Just search this forum and youll find a lot on those carrier bearings.

 

actually 46 on the BFG load range Ds. Check your rear shocks for oil leaks. I had one replaced under warranty. Also look on the inside of the rims for the stick on weights. I have lost 2. One I found laying in my driveway. I stuck it back on with some black RTV silicone. When I lost the weights the wheels were on the front so I knew right away it was a balance issue.

 

Ill look for leaks as soon as the bad weather passes.

Honestly what it feels like to me is like a shock has gone bad and is bouncing...

I was always under the impression that a wheel out of balance would make the issue be constant at the speeds, and not a hit or miss.

Its usually over the same parts of the roads Ive noticed driving too and from work. But again, this wasnt there a few months ago lol.

 

46 PSI is crazy in my opinion. That's why his ride was bumpy. Let some air out. 36 PSI is my max if fully loaded.

 

Well I lowered it down to 36, and even tried 34.

Its horrible now. I feel like the rear end of the truck is just fluttering on a washboard. This is not a "rough" feeling. Its not a jarring bump.

The best way I can describe it is to imagine a row of speed humps (really smooth tiny ones) and you drive really slow over them, but only in the rear lol. It feels like the back of the truck bad is bouncing up and down slowly. But everything inside the truck shakes.

 

Ok here's a video I took. You can see the seat shaking violently in the first few seconds. Then it goes a way and you get just the normal truck vibration. When the seat shakes like that, that's where I get my washboard ride.

https://carousel.dropbox.com/photos/cc/DD2eFQVtVRerB6W