I have a vibration that can be felt in the floor board especially with your foot on the throttle. I originally contributed it to a the center support bearing that I recent replaced due the rubber being bad. Changed the u joints too. I don't feel it in the steering wheel or the seat, just the floor especially the pedal.

The vibration comes and goes, cold or operating temp doesn't matter. Usually speed above 40-45. Sometimes it will stop as speed goes above 55 sometimes will last up to 70. I do have a vibration most of the time when hard on the throttle right before it changes gears (auto trans).

Searches I've done point toward the down pipe, but it was modified by previous owner and this issue is new and I don't have any extra noise with the vibration or I don't hear it. I've also read about front leaf spring mounts but I have a 2wd.

Things I've done so far:

Rotate and balance tires.

Replaced u-joints and center support bearing. Center support bearing was bad. Lots of vibration when towing.

After driveshaft repair it believe it stopped but then a week later it returned. Contributed it to driving on a bad road under construction with terrible pot holes. Was going very slow but thought maybe it knocked a wheel weight off. Had tires balanced and rotated but still had floor vibration.

Thought about the drive shaft out of balance but I figured that it would be consistent. I literally can drive it home with no vibration and drive it the next day with vibration.



Auto trans, Crew cab, 2wd, 7.3, long bed.

Any ideas to check?

 

Best guess is the down pipe. Check the clearance between it and the firewall as if it is touching the firewall it will vibrate the floor badly.

 

Thanks, I'll look more into it. What's the minimum clearance needed?

 

Best I could get was about 1/8 to 1/4 inch and that was pushing it. It's a tight fit with a 3 inch after market down pipe, if that's what you have. When the engine torques it's going to move a bit causing the down pipe to move also.

 

Auto or manual trans?

Edit: Just saw auto. That rules out a DMF

 

I had something kind of like this. took forever to find it. There was a bolt that fell down between the cross member and the back of the engine oil pan.

 

I remember you having that issue. I haven't had the chance to look into it lately. Hopefully tomorrow. Thanks for the reply