First post on this site;

Background: DIE hard Ford man. Owned 7 trucks in last 14 years. I even convert my boat from chev to Ford power.

With that said, My most recent superduty (6.0 made 11-10-03) has given me more fits that all my other trucks combined. I have solved most of them but It has come down to one problem that I can't get resolved.

The truck does have a rancho 4 inch suspension (as all my other's did) aftermarket tires etc.

The problem is a severe "buzzing" eminating from what I think is the transmission. Yes I have the 1700-2000 rpm exhaust drone, but this is different.

The Buzzing starts at 73mph, is totally independant of rpm, and only under heavy acceleration. It fades as you approach 80mph. Is is VERY noticable and agitating (not a light buzz in otherwords). Cruising at those speeds give no buzz. it is only under acceleration. Also, heavy accelaration at lower speeds also is buzz free. Again, not related to any specific RPM.

The truck has under 6,000 miles. I put the suspension on rightr away so I am not entirely sure if it plays a role.

I have balanced the drive shafts and replaced the front hubs. Not down on power. U joints look good. It is definitely not a tire problem, I have years of experience solving that issue.

Any advise/suggestions

 

It soudns like a resonance induced "buzz". Changes in stiffness and such can cause changes in a systems natural resonant frequency, kinda like a tuning fork. It wants to vibrate at that frequency. What this resonance does it greatly amplifly any vibration resident at that time or being applied to it. In this case it almost sounds like the acceleration is the hammer hitting the tuning fork. The harder you hit it, the more energy or excitment you apply to it. The "buzz" is probably there under cruise conditions but not loud enough to be bothesome. I would look for something attendent to the change made, the suspension, and see if there is a contact point with something that can buzz, say a shift of position on some component. But I would definitely look there first. It doesn't mean something is wrong, just that something is making a noise you don't like. Hope this helps rather than confuses.

 

Possibly, It really sounds like a misalignment of an shaft (or bent shaft) within the tranny (automatic).

Anyone else have this experience?

 

First…. WELCOME to FTE the best Family Ford site on the planet.
Next go to the bottom of the page……read through the Guidelines

Here is the links to help answer some of your questions

This is the link to the 6.0lL
https://www.ford-trucks.com/forums/f...play.php?f=107


This the Super Duty
https://www.ford-trucks.com/forums/f...splay.php?f=30

 

Unless you've already ruled out the tires air em up to 50 psi and see if it still there. (the buzz)

 

https://www.ford-trucks.com/forums/s...d.php?t=243821

Moved to appropriate forum

 

Sorry, and thank you

 

I have read through tons of other posts but have not found my particular problem.

Nobody else has experienced this?

 

Hang out it has been a slow weekend....

 

Will do. Just a little anxious as you can tell by my posting in the wrong forum.

 

Are you planning on taking it to your dealer

 

Already did. They unsist they can't detect any problems. I was not able to take them on the test drive.

This is the same dealer that told me it there was no problem when the truck acted like it was out of fuel with a third of a tank left in but somehow stopped doing it after I took it in and complained. They swear they did not reflash anything.

If someone else had already delt with this particular problem, I can specifically tell them where to look or what to fix. Yes, I can also find another dealer.