Drive Train Vibration Gen2 70mph+

[Hal993]

33,000 miles
New tires - road-forced by Discount Tire (the tires were out of balance, they fixed that... but the vibration is still there)

Truck vibrates on the interstate. It is hardly noticeable until 68mph or so... above 70, it becomes hard to ignore... seat, steering wheel, everything.

• Tires have been replaced and balanced
• Live Valve height has been re-calibrated (level, no load)
• I have reset the TCM adaptive Tables
• At speed, uphill, downhill, under boost, no throttle, vibration is the same
• At speed, downhill, once the vibration starts, shifting into neutral does not change the vibration
• changing to Sport mode does not change the vibration
•** When the suspension is moving under load (on the way down or on the way up.. like a big slow "woop" in the interstate) she is dead smooth.

Anyone else have this or know what it might be? Live Valve controller? Rear leafs? Tires not tightened in a star pattern? ??

I'd like to have some ideas before I take it to a dealer (Ford Premium Care Warranty).

 

[smurfslayer]

Is the truck stock? Are there _ANY_ suspension component modifications?
When did the issue start?

If the issue started with the tires, it’s almost certain that it’s the tires/balance - or lack thereof. Just because you got a RFB, doesn’t mean it’s right. Did you notice how many weights were on the wheels when you took it in? One of mine had 14 ounces of wheel weight in various positions to balance it out. Granted, discount tire did a credible job in only 60 minutes for 6 tires, but, it’s not factory perfect and none of my wheels have more than 6 ounces of weights.

Because they’re not seeking perfection, they’re trying to get you in and out as fast as possible.


Now, if it was there before the tires, something else could be going on.

Any recent changes other than tires?

 

[Hal993]

The truck is bone stock. OG Leafs. Tires are OEM K02.

The issue may have been there when I bought it, but was masked by:
1) an out-of-round tire... which was rectified, but the dealer couldn't balance tires, ... so then I had DT road-force the tires... which brought them in to balance... but the issue feels different now, but... as bad if not worse than before.

I'll have time on Friday or early next week to take if back to DT to re-check.

Notes I have from last trip to Discount Tire say.

LF - was .75
RF - "OK"... RO 49
LR - 1.00
RR - ok

I'm guessing those are ounces that were added to the "already balanced" tires. I believe DT tech said the Road Force balanced the RF... and it was a High RF, but came in to balance.

No other changes at all. Nothing added, no mods. I did tow a 5x8 U-Haul ~300 miles (just a queen bed in the trailer - not really any weight to speak of), and didn't notice it... ,because I was going under 70mph the whole time. After dropping off that trailer - on the way home (300miles), it was very evident that there was a problem, but I was going over 70mph.

 

[Nex]

How old are the tires? If they are factory I would replace them. Could have a sidewall failing.

 

[Hal993]

3 of them a brand new - OEM, but brand new. (1) is OG/factory with zero miles ... dealer moved the spare to the 4th position when rectifying the out-of-round tire condition that it had when I bough it.

maybe that 3 year old spare is trying to give up the ghost under load?

 

[Nex]

It's possible. Being trapped against the bed for 3+ years.

 

[smurfslayer]

3 of them a brand new - OEM, but brand new. (1) is OG/factory with zero miles ... dealer moved the spare to the 4th position when rectifying the out-of-round tire condition that it had when I bough it.

maybe that 3 year old spare is trying to give up the ghost under load?

no, I did the same thing, rolled that 5 y.o. spare into rotation and it’s been fine (added a TPMS).

move 1 tire from the front to the back. retest
move the 2nd tire from front to back, retest.

what is the vibration level.

FWIW, when I replaced the KO2’s, it took me 3 attempts to get a decent balance and it was DT road force. As I said before it’s not perfect but it’s very, very good. I have 1 or 2 out of 6 tires that aren’t as good and when they’re up front, it’s not as good, but tolerable. I’m going to give D/T another go at those 2.

your symptoms are like mine were after the first 2, pathetic balancing attempts.

 

[Space Ghost]

Discount tire is good but imo if you have a local ford/quicklane have them road force balance it. Theyve always been able to do a better job for w/e reason.
My last set of k02s one tire just was not balancing right and it was horrible, had it redone twice at discount before taking it to ford and they did a better job. Went from shaking to a mild rumble, still annoying.

 

[John813]

Maybe they make a **** ton and there's plenty of people with no issues, but I will die on that hill that those tires have poor QA/QC.

Also, depends on the tech for the road force balancing. Some care and others just want to get your job done and will let shit slide.