35s to 37s, rough ride

[HulkHartman]

2018 802a with 55k miles. Stock tires were due for a replacement, so i figured id go up to 37s since I have Eibachs. I went with 37x12.50x17 k02s C rating, also changes wheels to the RTR +18 17x9 charcoal wheel. (no rubbing at all BTW). With Eibachs and stock wheel/tire, the drive was smooth and comfortable. I have the current 37s set to 34psi all around.

Got the 37s put on at the local Ford dealership and 1st, they were out of balance, so they re balanced and did an alignment just to be sure. Tires were great now but the alignment was done incorrectly and my steering wheel was off the to left. Took it back and they did everything right. Since then I've used the truck as my daily and did some ~75-100 miles round trips. I feel a constant bump/kick/mini vibration in the seat. It gets worse on higher speeds but its not a consistent bump that would match tire rotation. It feels like EVERY bump in the road goes into my seat, even at low speeds.

Ford kept saying its hard to balance 37s just right, so I found a shop locally that had a machine that can roadforce balance them and had that done. No change. Was tempted to get balance beads thrown in instead.. but waiting on that.

The psi was 40 so i decreased to 34 all around and no change also.

I am going to cross rotate the wheels tonight to see if anything is better.

I do have my stock wheels and tires so if needed, I can swap them over and check to see if the rough ride goes away.

Any other suggestions?

 

[GCATX]

2018 802a with 55k miles. Stock tires were due for a replacement, so i figured id go up to 37s since I have Eibachs. I went with 37x12.50x17 k02s C rating, also changes wheels to the RTR +18 17x9 charcoal wheel. (no rubbing at all BTW). With Eibachs and stock wheel/tire, the drive was smooth and comfortable. I have the current 37s set to 34psi all around.

Got the 37s put on at the local Ford dealership and 1st, they were out of balance, so they re balanced and did an alignment just to be sure. Tires were great now but the alignment was done incorrectly and my steering wheel was off the to left. Took it back and they did everything right. Since then I've used the truck as my daily and did some ~75-100 miles round trips. I feel a constant bump/kick/mini vibration in the seat. It gets worse on higher speeds but its not a consistent bump that would match tire rotation. It feels like EVERY bump in the road goes into my seat, even at low speeds.

Ford kept saying its hard to balance 37s just right, so I found a shop locally that had a machine that can roadforce balance them and had that done. No change. Was tempted to get balance beads thrown in instead.. but waiting on that.

The psi was 40 so i decreased to 34 all around and no change also.

I am going to cross rotate the wheels tonight to see if anything is better.

I do have my stock wheels and tires so if needed, I can swap them over and check to see if the rough ride goes away.

Any other suggestions?

What psi were the 35's? I would probably go less than that in the 37's since they have a greater volume of air. Did you opt for the extra stiff nitrogen fill?

 

[2020FordRaptor]

2018 802a with 55k miles. Stock tires were due for a replacement, so i figured id go up to 37s since I have Eibachs. I went with 37x12.50x17 k02s C rating, also changes wheels to the RTR +18 17x9 charcoal wheel. (no rubbing at all BTW). With Eibachs and stock wheel/tire, the drive was smooth and comfortable. I have the current 37s set to 34psi all around.

Got the 37s put on at the local Ford dealership and 1st, they were out of balance, so they re balanced and did an alignment just to be sure. Tires were great now but the alignment was done incorrectly and my steering wheel was off the to left. Took it back and they did everything right. Since then I've used the truck as my daily and did some ~75-100 miles round trips. I feel a constant bump/kick/mini vibration in the seat. It gets worse on higher speeds but its not a consistent bump that would match tire rotation. It feels like EVERY bump in the road goes into my seat, even at low speeds.

Ford kept saying its hard to balance 37s just right, so I found a shop locally that had a machine that can roadforce balance them and had that done. No change. Was tempted to get balance beads thrown in instead.. but waiting on that.

The psi was 40 so i decreased to 34 all around and no change also.

I am going to cross rotate the wheels tonight to see if anything is better.

I do have my stock wheels and tires so if needed, I can swap them over and check to see if the rough ride goes away.

Any other suggestions?

Well my guess is that 37s would be rougher than 35s since the truck is made for 35s. That's a wild guess that probably isn't true.

 

[HulkHartman]

Psi on the 35s were 38ish. Rarely had an issue with it. I hope I didn't get the nitrogen fill! lol. Ill update the thread after I rotate here in about 2 hours.

 

[HulkHartman]

Got the tires rotated. Its not fixed, but its better. The front end feels much more smooth but feel more in the seat kinda. Mechanic said definitely feels like tire "noise". I forgot to mentioned the roadforce balance was only done to the rears. I have about 350miles on the tires, he mentioned to get the other 2 road force balanced and give it to about 1000 miles before we try new tires.

 

[GCATX]

Swap the old tires back on. Hopefully you'll find your answer. I went through this on a ram 2500 but did it since new. Several new tires/rims. It was something in the drivetrain. I traded the damn thing in.

Interestingly, I ran into the new owner in a parking lot. He hadn't changed anything and said the truck drove like a dream. I guess there is an ass for every seat.

 

[HulkHartman]

I'll get the road force done tomorrow ob the other 2, if that doesn't help or fix, ill swap old wheels and tires on this weekend.

 

[Space Ghost]

I'll get the road force done tomorrow ob the other 2, if that doesn't help or fix, ill swap old wheels and tires on this weekend.

Why were only two roadforced?
Also what were their #s from the road force machine?
Did you feel it in the steering wheel as well (the bumps)? More/less than the seat?

 

[HulkHartman]

The 2 were only roadforce balanced because i didnt have a whole lot of time that day so i said just do the rears. Ill try and find the paperwork on the roadforce to get the numbers. I had to push off to get the other 2 done tomorrow, work got a little busy today.

I feel it in the seat mostly. There was definitely a change after rotating the rears (RF balanced) to the front. The steering wheel feels great now when i thought before rotation it was good. It is a weird sensation, the steering feels great (no shakes or dead spots), alignment feels great - drives like stock, hitting big pot holes and large bumps/speed bumps at high speeds feels like butter, but driving down any average road it feels like constant little bumps/kicks/shake in the seat that is not consistent with speed. Under hard acceleration I don't notice it, cruise in traffic/around town its annoying. The part about hitting large bumps versus the small annoyances confuses the hell outta me. My Wife dailies a rubicon on 35s and says she doesnt notice the Raptor issues unless she pays attention, when i drive her jeep i feel it rides better than the raptor right now lol.

 

[Hotrod-Realtor]

I'm going to guess you have a tire that has a separated belt or similar problem. You should be able to see a wobble if you could spin each tire up using a spin balancer or maybe that road force balancer. It's likely going to be one of the tires that didn't get the road force balance on your last visit. Find that tire and replace it.