Suspension stiff and chassis vibrates after hitting bump

I have a 2022 limited with 20 inch wheels. I use it to tow light trailers and to have enough space to haul my wife's excess luggage. Doesn't go off road. Have 2k miles on it.

When the truck hits a bump mostly a strip of raised road that the axial hits at the same time, the truck reacts by first a somewhat jarring transmission of the bump but then followed by a several (for lack of better words) vibrations or undulations of the suspension. As if the shocks lack adequate rebound damping.
In an attempt to tune it out of the vehicle, I looked at the tire compliance. Recognizing the 20 inch tires at 35 psi would be pretty stiff, I compared the load ratings of this tire and previous generation Tundras I concluded that I could drop tire pressure considerably. I lowered them to 31 psi. The issues described were reduced by 50%. The condition seems to mostly in the rear suspension. When I drive my other truck and cars over the same road surface they do not exhibit this condition.

The initial hit I can live with but resulting oscillation is just unacceptable and a indication of faulty engineering or a flaw. Could be a flaw in my truck like faulty shocks? Is anyone else noticing this characteristic in their suspension?

This winter season I plan to add winter tires on 18 inch wheels for better snow traction and braking. 18 inch wheels should improve compliance even more but not necessarily the post hit oscillations.

Any input is appreciated

Saber

 

I've made a post about this EXACT thing somewhere in this group, but I just chalked it up to running E rated tires at 40PSI.

Regardless, I agree 100% that it's incredibly annoying. On my truck, it jerks the entire truck and it's enough to also make the transmission downshift a gear if I'm using cruise control.

I don't have air suspension. Basic SR5 shocks.

 

Let me guess, you have air suspension?
If so, your rear level adjustment arms need adjusted. Several threads on this.

 

The funny thing is I find overall my 2022 is a WAY smoother ride than my 2017 was. It's these raised bumps across the road exactly like what OP is saying that mine handles like complete crap on.

 

I do not have the air suspension

 

Sounds 100% like what my F150 did. It may be an artifact of the fully boxed frame, IDK. My F150 is fully boxed.

Bilstein 5100's cured it 95%. It still does it ever so slightly but its hugely better.

 

Probably related to the change to a fully boxed frame, which is stiffer and can transfer more vibrations, and the stock black shocks, which are marginal at best. The black shocks can have some trouble controlling even the stock tires on bumps, road imperfections, etc.

 

The comments on shocks makes sense . Annoying to think I need to buy after market shocks say with rebound adjustment to fix this.

Anyone with 18 wheels experiencing this issue?

 

I have a SR5 TRD Offroad on 18" wheels. I find that unlaiden the truck rides very stiff. Add 100 lbs and the ride is noticeably smoother. I am on stock tires at the moment around 35-36 psi. I haven't tried experimenting with lower pressures.

 

20" wheels definitely contribute to this as it reduces the sidewall alot and if you have E loads, you now have a stiffer tire with less sidewall so it makes sense.

 

Do you have a level kit? And what ply are the 35s?

 

I am guessing you could pick up a set of Bilstein 4600 or 5100(whenever they come out) or equivalent for the rear only and fix the problem for <$200.

 

Are the Bilstein 4600 or 5100 shocks the TRD ones that come with that package? I find the ride a bit harsher compared to my last truck but a bit smoother with the trailer attached. I am thinking that the ride is just stiff and needs to break in a bit. I have the blue shocks in mine that came with the TRD package.

 

The TRD shocks might be a variant of the 4600 but they are not the same as the ones Bilstein would sell aftermarket.

 

The tires are 265/60 R20 112H M&S. Bridgestone Dueler H/T. 5 ply tread, 2 ply sidewall. I do not know load rating. Bridgestone describes them as highway touring tires.

Soft would be my guess.

I don't have the load leveling option.

Some of the higher end Tundra's come with a damping system to isolate the cabin better. Anyone with one of the high trucks experiencing my issue?

 

Interesting. I wonder if you have a bad cab mount? My understanding is the limited and up trims have hydraulic cab mounts. I'd honestly just take it to Toyota and let them try and figure it out.

 

I might have to do what you suggested (take it to the dealer). I have the 2022 1794 and am experiencing the same "jolting" when the rear tires pass over bumps and stuff. First pickup owner here and love the truck overall but the ride could be a little "softer".

 

I also have this issue on my currently stock SR5, especially on any concrete highways instead of asphalt. Seems to get better with more weight in the truck bed, but I'd love to find a fix for the overly-sprung under-damped combo in the rear suspension.

My dealer blamed it on the road but I don't think that is a good excuse.

 

I have a 23 platinum without the air suspension and have the same exact issue. The dealer was absolutely no help. Anyone found a solution yet?

 

I took it to the dealer a few months ago. They took a while to figure out but in my case it seemed the truck bed was not settled in completely… they loosened the truck bed screws and they said the bed “settled” in to position and they retorqed the screws. It seemed to fix the bed rattle noise a little bit but nothing to do with the stiff ride. I recently took it to dealer for service and asked them to check the rear suspension to make sure it’s as per the TSB (Toyota service bulletin) and they said their measuring equipment was broken so now I’m waiting to go back to them at the next service appointment.

basically, you need to keep hounding them about it as they will do anything / everything in their power to get away from doing their job. Sometimes you’ll come across someone that actually looks out for ya but good luck. I’ll poss here after I get back to them again…

 

SR driver here. It's a brutal ride, feels like a HD suspension. It didn't feel quite like this when i did test drives or the first week or two. Unladen, the back hops a bit at higher speeds on rough freeway (no air suspension here). When I am going slow into my driveway and hit the brakes firm the front end bounces a few times. The suspension is just not tuned well at all. It's too bouncy at slow speeds, stiffens up too much at high speeds. Worst of both worlds. My wife just got carsick on our first road trip, so I'm frustrated. Adding weight in the bed has been the only relief so far. I switched to 17" wheels, this also made a difference, but not as much as weight in the bed. I want to swap the suspension for something road trip worthy, but just don't know where to go with it, don't really care about adding lift.

 

I've noticed this in my SR5 TRD OR as well. I boil it down to having a lightweight aluminum and composite bed and suspension capable of handling 1500 lb of weight in the bed or 11,000 lb of towing capacity. Pretty tough to make the suspension perform flawlessly while empty or with a load. I just slow down when going over a speed bump.

 

Mine is the same. The roads around the dealer were really good but man, I sure noticed it on my 450 mile drive home. The dealer had the tires at 40psi so going to lower and put some weight in the bed and see what happens.

 

40 cold psi is pretty high for p rated tires , max is only like 44

lower those things down and the ride will clean up

 

I just popped onto the app to see what my pressure was at.

I was surprised to see my tires at 45 psi Yikes. They were at 40 psi when I had them installed a few months ago.

These are "E" rated tires so they are like bricks! Time to let some air out!

 

Did you swap out the tires ?

toyota doesn’t use E rated on anything stock

 

I took the starter Michelins racing slicks off and put some Toyos on.

 

I see , if you have load E then i would not go lower than maybe 42-43, they will melt on the sides if you get down lower

 

Why is that? I have load Es, running em at 35 psi to compensate for the stiffer sidewall.

 

E tires have a max psi of 80. They're designed to run at around 70, with the ability to go to 80 for higher loads. Running them at half the pressure they are designed for will essentially be like having a flat. They will deform under load, causing excessive heat and failure.
On-road tires are not designed to be run half deflated like rock crawlers.