New driveline noise after lift

[bloc]

Has anyone had a new drivetrain related noise after lifting the front ~2” and the rear 1? At what point of lift on the back do we need adjustable links?

I put my kings on about a week before this trip and got a few hundred miles on them before leaving. Eventually I noticed a subtle sound at freeway speeds that was new. Roughly like having MTs. Not related to engine speed, seems related to wheel speed. It is higher pitched than what I’d expect from a driveshaft angle issue. I have a bubble level and may buy a protractor to try and eliminate that though.

Now in Colorado it is a bit more pronounced. It is like a combination of MTs and a radiator cooling fan roaring. Drive/coast doesn’t make a difference, so I’m thinking not diffs. Coasting in neutral it sounds the exact same. No change turning, which makes me question wheel bearings. I can’t hear anything with the windows down due to wind noise, at very low speeds nothing is noticeable.

I did make sure the CVs didn’t separate when I did the front shocks. Everything aligned great.

@Taco2Cruiser or @cruiseroutfit what do failing front or rear bearings start to sound like?

Or any input anyone else has, I’d appreciate.

 

[TeCKis300]

Could be anything. But I find it hard to believe that with a relatively mild lift, that it would have caused an issue with the driveline.

Thinking out loud of potential sources
- Kings I believe use spherical bushings or solid mounts that transmit more noise. As opposed to most street part and OEM parts that use rubber bushing that better isolate noise. Shouldn't transmit that much more noise in body on frame vehicle but there's potential
- Tire alignment and posture is changed so possible new tire noise as it scrubs in
- Could be wheel bearings

 

[bloc]

Could be anything. But I find it hard to believe that with a relatively mild lift, that it would have caused an issue with the driveline.

Thinking out loud of potential sources
- Kings I believe use spherical bushings or solid mounts that transmit more noise. As opposed to most street part and OEM parts that use rubber bushing that better isolate noise. Shouldn't transmit that much more noise in body on frame vehicle but there's potential
- Tire alignment and posture is changed so possible new tire noise as it scrubs in
- Could be wheel bearings

Good catch on the sphericals! The rear has poly mounts at the top but the front is spherical top and bottom, so more tire NVH may be making it through to the cab. My only issue with this logic is it seems to be getting slightly louder over time and I wouldn’t think that should happen.
Tire wear is even and clean, by the way.

 

[cruiseroutfit]

@Taco2Cruiser or @cruiseroutfit what do failing front or rear bearings start to sound like?

Or any input anyone else has, I’d appreciate.

Crunchy crunch, squeaky squeak or whirly whirl.

Hard to say really. We've dealt with may failed front and rear bearings between my personal stuff, Canguro stuff and customer jobs. We've sold/installed a plethora of rear axle kits and even more front wheel bearing assemblies (hub, bearing, etc). If I had to guess I'd say the front's wear much faster (based on Canguro and customer purchases) however mine are still tight (155k) and my rear failed much earlier. Who knows?

 

[bloc]

Another 1000+ miles to get home without issue, just that constant sound. Pretty sure it wasn’t there immediately after the suspension install, as I would have noticed.

Itll be a little bit of time but I plan to put it on stands and listen to each corner with a mechanics stethoscope.. as well as pull the rear driveline and see how the joints feel.

Thanks for the help everyone, I’ll post when I figure it out.

 

[rlynch356]

what does the rear pinion angle look like now? too extreme and you will have issues.

 

[dubaicruiser]

I also noticed a similar noise increase after the lift. I tried wheel alignment and it made a little smoother but the noise is still there.

 

[Markuson]

Basic, but mentioning anyway...

-Have you inspected your tires for scalloping/feathering?
...where the front edge of each tread block is taller than the rear edge? That can produce the kind of sound you describe (or sound that I might describe as you did).

If it’s that...you might perceive it as being more pronounced on concrete freeways compared to asphalt highways.

 

[linuxgod]

@bloc did you do the lift of have someone else install it? Just curious.

It's worth checking the bearings for play but unless you're just unlucky I doubt you have enough mileage for them to actually have gone bad.

I have a similar lift, though a bit less height in front now with the extra bumper weight. I did a diff drop kit as well after needing to re-boot a torn CV so my driveline angles are different than yours now. However I did not notice any difference in noise either before/after lift or before/after subsequent DD kit install.

All that said I have a lot of road noise atm but I largely attribute it to the Nitto RG tires as my front bearings only have ~40k on them. They were always a bit noisy but I do think they've gotten worse in the last 10k miles. Rotating them hasn't helped much though it will initially change the noise level/"direction" a bit so you might want to try that to see if the noise follows a bit. (I do get some wind noise from the roof rack (and the copious crap on it) and the snorkel, but I can eliminate the roof rack by closing the sunroof cover.)

My $0.02 - I doubt what you're hearing is driveline noise. Could be bearings, could be tires, could be different airflow under the vehicle causing something to drone/vibrate.

 

[linuxgod]

If it’s that...you might perceive it as being more pronounced on concrete freeways compared to asphalt highways.

@Markuson makes a good point, if it's tire noise it tends to vary depending on the road (fresh vs old asphalt vs concrete). If it's bearing noise it'll be extremely constant.

Side note: if your alignment is off post-lift then your tires could be hitting the pavement differently and causing additional noise. combine that with continued driving in that different alignment for a long trip and perhaps they're now wearing odd and getting even noisier?

 

[bloc]

Thanks @TeCKis300 @cruiseroutfit @rlynch356 @dubaicruiser @Markuson nad @linuxgod for the suggestions. The following was about half of my day:

Pinion angle was within .2 degree of the TC output flange, and rear u-joints felt great on manipulation, so I don't think rear driveline is the issue. I didn't remove the front, but nothing should have changed with the lift so I'm betting that's not it.

As pictured I had the truck on jack stands then engaged the CDL, and put it in drive. Turns out the rear brakes were dragging and only one side spinning, so I had to remove those rotors. With a mechanic's stethoscope, there are no obvious bearing issues. Fronts were completely silent.. it was eerie. Rears were a nice hiss, just like I'm used to. Same for both bearings on the rear diff, front diff even quieter, output bearings silent too. So, I feel confident it isn't a bearing issue.

Tire wear is all very even, no cupping or abnormal wear to speak of. The shop didn't give me a printout but the tech seemed to know what he was doing (22yrs experience at that one "alignment only" shop.. rare) and said everything was in the green, and he didn't even need to max out any of my adjusters.


So at this point I'm back to @TeCKis300 theory that it is the spherical bearings sending more NVH through the suspension into the cab. Might even be made worse by my relatively quiet P-metric tires. Obviously I'll be paying close attention to whether the noise seems to get more prevalent, but for now I'm not worrying about anything at least.

Still, if anyone has ideas, I'd like to hear them.

Side note: apparently the extra suspension travel offered by the kings allows the front KDSS arm to lightly hit the body mount on that side under the core support, and the rear KDSS arm to kiss a bracket on the frame, tearing it's boot. I'll be putting this thing on an improvised ramp soon to see how bad these interference issues are.

 

[linuxgod]

So at this point I'm back to @TeCKis300 theory that it is the spherical bearings sending more NVH through the suspension into the cab. Might even be made worse by my relatively quiet P-metric tires. Obviously I'll be paying close attention to whether the noise seems to get more prevalent, but for now I'm not worrying about anything at least.

Sounds like your underlying problem is that you don't crank up the stereo loud enough. I get a lot of tire and wind noise but I hardly notice it

Side note: apparently the extra suspension travel offered by the kings allows the front KDSS arm to lightly hit the body mount on that side under the core support, and the rear KDSS arm to kiss a bracket on the frame, tearing it's boot. I'll be putting this thing on an improvised ramp soon to see how bad these interference issues are.

I'd be interested to see pics of this.

 

[bloc]

Sounds like your underlying problem is that you don't crank up the stereo loud enough. I get a lot of tire and wind noise but I hardly notice it



I'd be interested to see pics of this.

Fair assessment on the music..

It'll definitely get posted when I collect some more data.

 

[Cruisin911]

Side note: apparently the extra suspension travel offered by the kings allows the front KDSS arm to lightly hit the body mount on that side under the core support, and the rear KDSS arm to kiss a bracket on the frame, tearing it's boot. I'll be putting this thing on an improvised ramp soon to see how bad these interference issues are.

I'd be interested in this as well. Ive had my setup flexed to its limit and haven't seen the issue you're dealing with WRT the KDSS. I have seen the drivers side KDSS LCA link angle being overly stressed in the forward direction when fully extended down, but other than that no issues.

 

[bloc]

I'd be interested in this as well. Ive had my setup flexed to its limit and haven't seen the issue you're dealing with WRT the KDSS. I have seen the drivers side KDSS LCA link angle being overly stressed in the forward direction when fully extended down, but other than that no issues.

I had the front end on jack stands with suspension totally dropped out as in the picture above and the bolt on the front end of the KDSS arm was definitely hitting the bolt under the core support.. though of course I didn't snap a picture. And yes I did see that on the link.

I'm not sure when the rear would have hit other than in Colorado a few weeks ago, but the tears/marks are there and the mark on the frame bracket is fresh... Hence my plan to put it on a ramp. And post about it.

 

[TeCKis300]

That's as thorough of an inspection as I've seen anyone do. Thanks for chasing and giving us feedback.

I assume you have UCAs as well? Depending on the types of joints, can create or translate additional NVH into the chassis too. Fortunately, body on frame inherently has another layer of isolation, but I've had these make significantly more noise in unibody cars.

Curious as you flex your rig and probably for another thread. Mind measuring max droop on the front and rear axles? Curious how much more down travel you're getting in the suspension. It would be cool to create a database with those details depending on setup.

 

[Yossarian]

It's worth checking the bearings for play but unless you're just unlucky I doubt you have enough mileage for them to actually have gone bad.

My left side front and rear bearings were making noise and replaced at 68k. Thankfully I had the Toyota extended warranty, as the dealer tried to say the cause had to be an accident. $2500 plus.

 

[bloc]

That's as thorough of an inspection as I've seen anyone do. Thanks for chasing and giving us feedback.

I assume you have UCAs as well? Depending on the types of joints, can create or translate additional NVH into the chassis too. Fortunately, body on frame inherently has another layer of isolation, but I've had these make significantly more noise in unibody cars.

Curious as you flex your rig and probably for another thread. Mind measuring max droop on the front and rear axles? Curious how much more down travel you're getting in the suspension. It would be cool to create a database with those details depending on setup.

I’m actually using stock UCAs since the goal was minimal lift. And managed to get a pair of brand new takeoffs from a 2020, so those shouldn’t be the issue. I may end up going with ARB arms eventually to lessen binding and get the alignment adjusters closer to the center, but that isn’t a priority.

I’ll likely start a new thread for the KDSS contact issue, if it turns out I’m not crazy. and yeah get some measurements. I haven’t forgotten about your request for the rear extended length.. the plan is pull the rears and double check the bushings since some problems have been reported with them on other rigs. I’ll get the rear numbers at that time.

 

[dubaicruiser]

I am closely watching your follow-ups. I redid alignment as I found there is a very little pull towards the right when letting the steering go and also my front tires are slightly angled inwards. solved both of those issues but the extra noise came with the lift is still there. I also got a minimal lift (1.5inces) and uca is stock. I notice the noise only on the tarmac not offroad.

 

[dubaicruiser]

Any updates?