dana 60 "bounce" at freeway speeds???

[NorCal_Chris]

So this has been bothering me for a while.

When im on the freeway assuming 55-65mph my driver tire feels like it is bouncing up and down. I say drivers because when i look at the hood it looks like it is just coming from that one side, and i feel it bad in my column. It makes my doors shake and the whole damn truck.

I thought it was my 42s at first... but when i took em off to groove them and stuck my 36 radials back on it still does it. Anyone have a thought to what this could be? I have no death wobble now that i have preload adjusters on my kingpin caps. Think my shock might be fubared and rebounding funny? i was gonna try and take the shock off and make a trip and see.
Could it be wheel bearing going bad?

Im at home with my little guy while the wife is out and about so cant do any actual troubleshooting, just web mechanics.

 

[chulisohombre]

So this has been bothering me for a while.

When im on the freeway assuming 55-65mph my driver tire feels like it is bouncing up and down. I say drivers because when i look at the hood it looks like it is just coming from that one side, and i feel it bad in my column. It makes my doors shake and the whole damn truck.

I thought it was my 42s at first... but when i took em off to groove them and stuck my 36 radials back on it still does it. Anyone have a thought to what this could be? I have no death wobble now that i have preload adjusters on my kingpin caps. Think my shock might be fubared and rebounding funny? i was gonna try and take the shock off and make a trip and see.
Could it be wheel bearing going bad?

Im at home with my little guy while the wife is out and about so cant do any actual troubleshooting, just web mechanics.

when she gets home lift that side axle and tire and see if it wobbles side to side or with it in the air you might see something thats loose.spinning the tire may show something off,but you cant get that sucker up to highway speed by hand.kinda sounds like a bearing going.

 

[NorCal_Chris]

well it seems to have a little wobble up and down. just a little though. Im guessing it shouldnt have any wobble at all.

 

[Amtek]

I'd check both the kingpin spring/bushing/preload adjuster and your wheel bearings. There should be no play at all. From your description it sounds like death wobble to me.

 

[sweetk30]

if you have never or been more than 2-3 years get new king pin springs and bushings.

and clean/check / repack wheel bearings.

then check the steering stuff when your down there just to be safe.

 

[jekquistk5]

if you have never or been more than 2-3 years get new king pin springs and bushings.

and clean/check / repack wheel bearings.

then check the steering stuff when your down there just to be safe.

pretty sure he has WFO springless arms. Make sure there is no play and that your set screw didn't back out.

 

[NorCal_Chris]

Yeah springless arms. If my preload was loose I would know because my buddy tge death wobble would let me know, but I will check em. bushings are just a month old. Its definatly not death wobble, as I had that baaaad before. I will pull the wheel bearings and give them an inspection and see how they look. Will let you guys know

 

[NorCal_Chris]

Update.


This is still happening. I tried airsoft bbs in tires and it is a little calmer, but still does it.

Put truck on jackstands and it is solid as a rock. No slop anywere. Hydro assist too.

what the feck is causing this?

 

[big pappa b]

Are your rear shocks the same size as the front? If so, swap them or just swap left and right front to see if things change

 

[NorCal_Chris]

Are your rear shocks the same size as the front? If so, swap them or just swap left and right front to see if things change

they are simular. good enough to test with i imagine. I will give that a whirl in a few hours.


Oh and

plain d60 front

springless cap and crossover arm

cm performance bronze kingpin bushings

2x.250 wall tierod

hydro assist

 

[Tnsejed]

Do you find that it is a harmonic issue?

I know you said you changed tires and the issue was still present but did you also change rims with that tire swap?

If not have you thrown this rim on a balancer to check for squareness?

I would start with checking runout on just about everything first, from the tire to the rim all the way in to the axle and then start from there.

Web mechanics suck, about as bad as shotgun diagnosis and then throwing parts at things...

 

[NorCal_Chris]

yeah it does it with my 42s on 15s and my 36s on 16.5s


the 36s are radials and rode like glass when i had em on my d44 before.



Also my d60 didnt always do this. It was a progressive problem after a few months of having it with no issues.

 

[TheBeast_88K5]

I say we have a wheel bearing party tomoro...

But srsly, I didn't do mine today.

 

[NorCal_Chris]

I say we have a wheel bearing party tomoro...

But srsly, I didn't do mine today.

Yeah i dunno..... everything is super tight no slop when i shake the wheel at all. Makes me sad.


i would rather wheel than fix it anyways, maybe i can bash it into working right

 

[owenst7]

Springless arms:
How did you set the preload on the set screws?

There should be 20-25 lbs resistance when measured at the TRE hole. Note this is a measurement of resistance at a given distance from the fulcrum, not a torque. Also, it is a value for a single knuckle, so you need to disconnect the tie rod from one side and the drag link if connected to that knuckle. I have a luggage/fish scale that I hook through the hole in the knuckle and measure with the knuckle pointed forward, scale perpendicular to the knuckle, and measure after the knuckle moves (you're measuring kinetic friction not static friction, just like pinion bearing preload).

What is the condition of the lower bearing?

Really no reason to suspect shocks here. Shocks can't apply a force anywhere without force being applied to them. This is also why steering stabilizers don't cause death wobble nor do they correct it.

 

[NorCal_Chris]

Springless arms:
How did you set the preload on the set screws?

There should be 20-25 lbs resistance when measured at the TRE hole. Note this is a measurement of resistance at a given distance from the fulcrum, not a torque. Also, it is a value for a single knuckle, so you need to disconnect the tie rod from one side and the drag link if connected to that knuckle.

What is the condition of the lower bearing?

Really no reason to suspect shocks here. Shocks can't apply a force anywhere without force being applied to them. This is also why steering stabilizers don't cause death wobble nor do they correct it.

I basically just tightened them a little at a time "feeling" how much resistance i had. I would guess im in that ballpark. It takes a bit of effort to turn the wheels when its on jackstands.

The lower kingpin bearing was never touched or inspected. I had bad wobble before and replaced a boogered stock plastic capwith bronze, then got the springless arms and set the preload and cured DW. then a few months later i have this crappy bounce wobble thing.



It feels almost like an oscillating action. Like at 65 it will bounce then wait a sec or 2 and then bounce again. sometimes it is really rythmic.


I figured since i had no play that the bottom bearing was good.

 

[owenst7]

I basically just tightened them a little at a time "feeling" how much resistance i had. I would guess im in that ballpark. It takes a bit of effort to turn the wheels when its on jackstands.

The lower kingpin bearing was never touched or inspected. I had bad wobble before and replaced a boogered stock plastic capwith bronze, then got the springless arms and set the preload and cured DW. then a few months later i have this crappy bounce wobble thing.



It feels almost like an oscillating action. Like at 65 it will bounce then wait a sec or 2 and then bounce again. sometimes it is really rythmic.


I figured since i had no play that the bottom bearing was good.

Sounds like that's probably not the issue then. It's really not an exact thing, as long as it's not too loose. A bit too snug isn't going to hurt anything really.

Sounds to me like possibly any number of things. I'm sure you already thought of this, but have someone oscillate the steering lock to lock with all the weight on the tires and get under there and watch every moving part closely. I even put my hand on all the joints as sometimes you can feel the play easier than you can see it. That should rule out any of the steering. Then I'd probably pull each driveshaft and see if that does it...it's kind of amazing how much a very slight amount of runout on a driveshaft can throw a truck around. After that, the next step would probably be taking the hubs apart and inspecting the spindle/bearings...although you could rule out a lot of related issues by just checking runout with a dial indicator on the wheel, WMS, or brake rotor, etc.

 

[Fordum]

Ok, if you have not done this yet, we need to go back to basics. Get someone to follow you, preferably with two people in the chase car.
Get it to the bounce speed, and let them come alongside and see what it actually happening.
It probably would help if you watched while they drove too.

Sometimes actually seeing the problem will give you a clue. It might not be the wheel you think, even though is seems it has to be.

If its for sure that wheel, then you need to do the wheel bearings. I suggest that if you do not find anything wrong with them, pull the other side and swap as much stuff as you can left to right.
Unless the antibiotic is still dumbing me down, you should be able to swap the hub, drum or disk, wheel and tire.

If the problem moves, then it is some part of what you swapped. If not, then its in the suspension, or the spindle is loose.........

 

[TheBeast_88K5]

Yeah i dunno..... everything is super tight no slop when i shake the wheel at all. Makes me sad.


i would rather wheel than fix it anyways, maybe i can bash it into working right

It's worked before...

I fixed my wobble, on the rocks...
So, we still on fer tomoro?

 

[TheBeast_88K5]

Fordum always makes a painful amount of sense...

Ok, if you have not done this yet, we need to go back to basics. Get someone to follow you, preferably with two people in the chase car.
Get it to the bounce speed, and let them come alongside and see what it actually happening.
It probably would help if you watched while they drove too.

Sometimes actually seeing the problem will give you a clue. It might not be the wheel you think, even though is seems it has to be.

If its for sure that wheel, then you need to do the wheel bearings. I suggest that if you do not find anything wrong with them, pull the other side and swap as much stuff as you can left to right.
Unless the antibiotic is still dumbing me down, you should be able to swap the hub, drum or disk, wheel and tire.

If the problem moves, then it is some part of what you swapped. If not, then its in the suspension, or the spindle is loose.........