Hi everybody... well I've been going round and round with this vibration for weeks now. Its a 99 5.4l f-150 and I originally thought that it was a vehicle speed vibration, and took it to ford. The Looked through everything and found nothing. Then called me back and told me that they reproduced the same vibe while running the truck through different rpm ranges while the truck was in park. They were right. I have a low tone rumble vibration at about 1100 rpm and again at 1950-2000. It felt, and still feels like it comes from the rear, but now i know it doesn't. But the vibration is felt in the seat and armrest, not so much in the steering wheel. Any ideas you guys might have would be great. Here is the link to my previous post (when I thought it was vehicle speed related) so you can maybe pick up on some things i have left out here.
https://www.ford-trucks.com/forums/9...vibration.html
I've now realized that I thought it was vehicle speed related because at these rpms the truck is going about 30mph and 65mph respectively... guess I just wasn't paying close enough attention.
I know there are some really bright people on here with tons of experience... I hope you can get me pointed in the right direction.