I recently had the same problem and it was an alignment issue. Vibration was very noticeable at 70mph.Wheel spacers causing vibration at high speeds. I had had my tires rude force balance twice. 32/10.5R17 on stock wheels
do you have wheel spacers on? And I have the falken AT3I'm going through the same issues with vibration at 70. I don't have wheel spacers. If no one is sitting in the passenger seat it shakes pretty bad. It's done it since I bought the truck new in June with a 3 inch leveling kit, aftermarket 20s with 32 inch tires. I wasn't fond of the original wheels so replaced those and no change. My thought would be the Toyo AT3s. But still trying to figure it out.
If you haven’t recalibrated your speedometer after adding those 32s, what you’re reading as 80-85, is actually more like 90+.80-85mph the seats start to shake
I have a tune but it didn’t fix the speedometer or tire size and I don’t know how to change the tune. SCT bull dogIf you haven’t recalibrated your speedometer after adding those 32s, what you’re reading as 80-85, is actually more like 90+.
Your truck likely shimmied at high speeds of 90 plus before the spacers (it’s a Ranger thing) but you likely never, or rarely drove at that speed. Now you drive that fast often but your speedometer reads lower.
Those big tires throw your speedometer off - try driving at 75-80 according to your speedometer, which is really more like 80-85. it probably feels just like it used to.
Anyway, just a thought.
No wheel spacers.do you have wheel spacers on? And I have the falken AT3
For my issue the dealership said the same thing however I not only see the seat vibrating but feel it in the steering wheel which would tell me that it may be the tires. A trip to FL from KS had my hands feeling a little numb after awhile from the vibration in the steering wheel.I may be wrong but with it being so noticeable in the seat indicate it’s coming from the rear wheels?
If so maybe try rotating the tires first to check to see if it moves and if not try rotating the spacers. To help Identify the problem.
I have spacers and no issues
Just because you had an alignment doesnt mean too much as the toe could be set incorrectly. I myself figured this out after installing the Old Man EMU lift kit on my truck. I wouldnt be suprised if it is similar with your truck where toe is set at zero but the moment you get in the toe goes out causing high speed steering shake. Due to this i had to sit in the truck during the alignment to fix this.I did have a alignment not to long ago. But alight doesn’t have anything to do with vibration at night speeds.