GEN 2 Occasional shudder at 80ish

[Grimmwit]

Long post ahead - sorry.

New 802a 2020 Raptor. Stock tires and wheels - not the bead lockers. Truck is 100% stock except for the radio antenna.

I commute from Albuquerque to Santa Fe twice a week. Speed limit posted at 75, usually driving 80. The road is a mix of worn and new pavement. The issue occurs on both surfaces. Tire pressures set cold to 38 front, 36 rear.

From the time I've had it (late May 2020), I get a shudder that for the life of me I can't identify. What I've done to date:

• Took to Firestone and had wheels balanced and alignment checked / adjusted.
• Had the tires rotated during first oil change.
• Took to dealer. Wasn't surprised that a difficult-to-reproduce issue came back with no problems observed. To their credit, they drove it about 30 miles on I-25. Whether they were really paying attention, or just enjoying a paid break, who knows.
• Convinced dealer to do a road force alignment.

The alignment and wheel balancing improved the drive around town, but no change at highway speeds.

I have noticed that in a headwind, it seems more prevalent. I get buffeted around a bit, but the shuddering is separate from the buffeting.

I can reproduce the sensation by downshifting from 10th to 8th while at speed. Told the dealer guys that, they said that's normal.

In June, I drove the truck to Colorado and drove it all over the place. It drove smoothly, but never at speeds above 75.

At this point I'm inclined to think it's a mechanical issue. My only other wild theory is some sort of wind conditions that cause some swirling in the truck bed or something along those lines.

I haven't done any other interstate driving outside of that corridor. The trip to CO was on state highways with lower speed limits, so the speed conditions didn't match.

The last dealer tech (guy who did the road force balance) suggested that with the stock tires some road vibration at high speed is inevitable. Yet I read here and other forums how owners seem to have really smooth rides. So I don't think that is reliable.

I drove the same stretch frequently from January until I got the Raptor in late May. I was driving a stock 4Runner, and never observed the shuddering at all - so I don't think it's a road surface issue.

I owned 2015 & 2016 F150's previously. Both crew cabs. The first with the 2.7L engine, the second with the 3.5L. Neither of them drove anything like this; the latter cross country from NH to NM when we moved. But I acknowledge mechanically there is a lot of difference between those trucks and the Raptor.

Any thoughts / suggestions? At this point, I'm inclined to try a different dealer and see if I get any further.

Thanks in advance for any suggestions offered.

 

[Oldfart]

I only have 2,000 miles on my 802A '20, but I can tell you that it is very smooth at all speeds up to 100 or so, with no odd vibrations or shaking present. I think I would go to a different dealer.

 

[CoronaRaptor]

Yeah, that's BS, these tires run smooth to 100 and beyond, even with 20 psi in them, don't ask! Not to sound like your dumb or anything, but if you have the back windows down and the front ones up, you can get that air sound, that makes it seem like the truck is shimmering when its not at high speeds. Maybe get somebody to follow you on the highway when you are going 80sih and see if the truck looks smooth at speed, also if you let off the gas and coast at above 80 is it smooth? If it is smooth with your foot off the gas, then it is most likely a driveline issue somewhere.

 

[ItsAMe]

I get it as well. 2020 SCAB 802A. I find it happens on specific stretches of road and attributed it to the material type of the road or the way it was finished. Interested to hear what others think.

Edit:

It doesn't seem specific to speed for me

 

[CoronaRaptor]

I get it as well. 2020 SCAB 802A. I find it happens on specific stretches of road and attributed it to the material type of the road or the way it was finished. Interested to hear what others think.

Concrete is worse for wheel bounce, I have found, especially on the 10 freeway east of LA

 

[ItsAMe]

Concrete is worse for wheel bounce, I have found, especially on the 10 freeway east of LA

Yeah, it was definitely that concrete with the ****** rough finish. Asphalt hasn't been an issue. The first time it happened, I was concerned but after hittingg that specific stretch again and experiencing it, I realized it's more of a pavement issue. The feeling of it seemed like a smaller version of the wobble of death on Jeeps.

 

[CoronaRaptor]

Yeah, it was definitely that concrete with the ****** rough finish. Asphalt hasn't been an issue. The first time it happened, I was concerned but after hittingg that specific stretch again and experiencing it, I realized it's more of a pavement issue. The feeling of it seemed like a smaller version of the wobble of death on Jeeps.

Exactly, the first time I experienced that, I thought i had a flat tire or broke something, try pulling over on that stretch of highway in LA, not fun! And for nothing, ha ha.

 

[GCATX]

You should ask for the road balance numbers. Sometimes if the number is too high, it cannot be overcome. Also, if the tires are flatspotted, it will never ride smooth. If the dealer used a good Hunter machine it should spit out the balance numbers.

I would hold out for a new set of tires. If it sat on the lot for a good while before you bought it, they may be flatspotted. I bought a new chevy that had sat on the lot for almost a year. All the balancing in the world didn't fix it. New tires and it was perfect.

 

[isis]

Put the stock antenna back on.

 

[Grimmwit]

Yeah, that's BS, these tires run smooth to 100 and beyond, even with 20 psi in them, don't ask! Not to sound like your dumb or anything, but if you have the back windows down and the front ones up, you can get that air sound, that makes it seem like the truck is shimmering when its not at high speeds. Maybe get somebody to follow you on the highway when you are going 80sih and see if the truck looks smooth at speed, also if you let off the gas and coast at above 80 is it smooth? If it is smooth with your foot off the gas, then it is most likely a driveline issue somewhere.

Yeah, windows up always. All my F150s have had a horrible resonance with the windows down at speed.

I'll try the test you suggest.

Thanks.