Bump Steer/steering wheel goes nuts

[ssj4sadie]

Truck specs: 2018, 30k mi, Geisers, +3HD Deavers, have about 450lbs in the bed, and 315/70 KM3’s.

Long story: when it was stock (approximately 25k mi) it started to drift/track hard with the road with odd steering input, almost like lane assist was on when it was not. Had an alignment done and explained the issue to the tech, he attributed the issue to the worn out K02’s. Thinking it was a tire issue, I went ahead and installed the Geisers and Deavers, and aligned afterwards (specs attached) Issue still persisted. Made the move to new KM3’s and issue still persists. Any thoughts?

 

[smurfslayer]

Long story: when it was stock (approximately 25k mi) it started to drift/track hard with the road with odd steering input, almost like lane assist was on when it was not

only certain roads, certain stretches of roads. is it happening off road?

Had an alignment done and explained the issue to the tech, he attributed the issue to the worn out K02’s.

Color me skeptical, but, we’ll come back to this.

Thinking it was a tire issue, I went ahead and installed the Geisers and Deavers, and aligned afterwards

I totally do not get the logic of altering the suspension components and re-aligning when you have a suspected tire issue.

Issue still persisted

Made the move to new KM3’s and issue still persists

Any thoughts?

You haven’t made this any easier on yourself by modifying the suspension with this suspicious behavior.
I have and have had a lot of vehicles that will ‘follow ruts’ in pavement.

what psi were you most frequently running with the KO2’s?
does it do this on new-ish, good condition, clean and level pavement?
does it pull in one direction or another?
does the conditions persist with wheel / tire positions changed?
Any unusual wear pattern on either old KO2’s or new KM3’s?

The thread title is a bit of a more severe description than the write up. Could you elaborate a little on the symptoms?

 

[GordoJay]

Thinking it was a tire issue, I went ahead and installed the Geisers and Deavers, and aligned afterwards (specs attached) Issue still persisted. Made the move to new KM3’s and issue still persists. Any thoughts?

I think that you've given up any hope of getting it fixed under warranty.

 

[Muchmore]

This sounds vewy, vewy suspicious. Almost like I've heard this before.

 

[HOLLYWOOD 1]

Welcome to FRF, Helio!

 

[ssj4sadie]

only certain roads, certain stretches of roads. is it happening off road?

Pretty much everywhere where the road is uneven/the suspension unloads. Have not taken it off-road since last June, but I would assume the issue to be exacerbated.

Color me skeptical, but, we’ll come back to this.

What is there to be skeptical about? Alignment was out of spec and they adjusted it. Told me the tires were ****** (of which I knew), everything to my knowledge pointed to tires that were ****** and an out of whack alignment.

I totally do not get the logic of altering the suspension components and re-aligning when you have a suspected tire issue.

Hindsight is 20/20. However, this went on over the course of many months where I was driving the truck 250ish miles a month (thanks COVID).

You haven’t made this any easier on yourself by modifying the suspension with this suspicious behavior.
I have and have had a lot of vehicles that will ‘follow ruts’ in pavement.

what psi were you most frequently running with the KO2’s?
does it do this on new-ish, good condition, clean and level pavement?
does it pull in one direction or another?
does the conditions persist with wheel / tire positions changed?
Any unusual wear pattern on either old KO2’s or new KM3’s?

The thread title is a bit of a more severe description than the write up. Could you elaborate a little on the symptoms?

It is felt bump steer when the suspension is unloaded/loaded and odd tracking on the road in uneven conditions. The steering wheel will give erratic feedback depending on severity of the unevenness/bumps in the road. I was generally 38/36psi F/R with the K02’s. The tires were worn unevenly with the inner portion more worn (not to mention the tread was chuncked from off-roading on sharp shale).

The past aside and why did x vs y is irrelevant. Looking at my current setup/alignment settings...any idea?

I think that you've given up any hope of getting it fixed under warranty.

Who said I was trying to get it fixed under warranty?

This sounds vewy, vewy suspicious. Almost like I've heard this before.

So you have something of use to add? Or are you just letting shit from other threads/situations bleed over here?

 

[GordoJay]

Who said I was trying to get it fixed under warranty?

No one, but that's all I have to contribute, sorry. Seems like it might could have been a warranty issue had you wanted to pursue it before swapping springs. Buying the new tires first would have shown whether tires were the problem and if they weren't, you could have taken it to the dealer and nailed it down before doing the springs. Water under the bridge now.

 

[TwizzleStix]

View attachment 163412 Truck specs: 2018, 30k mi, Geisers, +3HD Deavers, have about 450lbs in the bed, and 315/70 KM3’s.

Long story: when it was stock (approximately 25k mi) it started to drift/track hard with the road with odd steering input, almost like lane assist was on when it was not. Had an alignment done and explained the issue to the tech, he attributed the issue to the worn out K02’s. Thinking it was a tire issue, I went ahead and installed the Geisers and Deavers, and aligned afterwards (specs attached) Issue still persisted. Made the move to new KM3’s and issue still persists. Any thoughts?

What were the alignment specs BEFORE you aligned it the first time? What you describe could be a few things, but usually it's caused by the toe being off quite a bit, tires inflated too much or too little, also loose "joints" (ball joints, tie rods-inner and/or outer, control arm bushings), and even loose steering rack. There is also the steering position sensor mounted in the steering column that feeds steering wheel position to the EPAS rack.

As others have said, it really is a bad idea to modify something that has this type of problem. That said, it can be diagnosed if taken to a competent shop. A general repair shop or ****** alignment shop is not a good place to go for problem diagnostics. I've also found that the newer, laser/digital chassis alignment machines are VERY fragile at the alignment heads that attach to the wheels. If everything is perfect with the machine calibration, they are great, as in quick & easy. HOWEVER, I've seen them be out of spec quite a bit meaning the printed sheet looks good, but the actual alignment is whacked.

 

[CoronaRaptor]

1) are you on the stock rims still?
2) what tire pressure are you running
3) I would try a different alignment shop ( even got to a Ford Dealer)
4) Good luck bro. those are nice normal mods on your truck.

 

[ssj4sadie]

No one, but that's all I have to contribute, sorry. Seems like it might could have been a warranty issue had you wanted to pursue it before swapping springs. Buying the new tires first would have shown whether tires were the problem and if they weren't, you could have taken it to the dealer and nailed it down before doing the springs. Water under the bridge now.

Like I said earlier, hindsight is 20/20.

What were the alignment specs BEFORE you aligned it the first time? What you describe could be a few things, but usually it's caused by the toe being off quite a bit, tires inflated too much or too little, also loose "joints" (ball joints, tie rods-inner and/or outer, control arm bushings), and even loose steering rack. There is also the steering position sensor mounted in the steering column that feeds steering wheel position to the EPAS rack.

As others have said, it really is a bad idea to modify something that has this type of problem. That said, it can be diagnosed if taken to a competent shop. A general repair shop or ****** alignment shop is not a good place to go for problem diagnostics. I've also found that the newer, laser/digital chassis alignment machines are VERY fragile at the alignment heads that attach to the wheels. If everything is perfect with the machine calibration, they are great, as in quick & easy. HOWEVER, I've seen them be out of spec quite a bit meaning the printed sheet looks good, but the actual alignment is whacked.

I attached the wrong specs in the OP. This is before and after when the suspension was stock with the KO2's.
This is after with the Geisers, Deavers, and KO2's

1) are you on the stock rims still?
2) what tire pressure are you running
3) I would try a different alignment shop ( even got to a Ford Dealer)
4) Good luck bro. those are nice normal mods on your truck.

Stock forged wheels. They were generally about 38/36 F/R. As you can see on the sheet the psi would swing wildly.