Tsb 07-5-11 Vibration/hop At 40-48 Mph - (8.0 Hz)

[TampaDieselFX4]

Hate to resorect this thread but This TSB title comes up for my 07 and I have not had it done, and I have bad vibes in the 40-50mph range (hopping really). Did this TSB fix it? I've checked my driveline angles and it's kosher. perfect really. Tcase and pinion are the same, and the 2pc shaft is straight with no angle differences. so it's not driveline angles that are causing the vibe. and it only happens at 40-50mph.

 

[powerboatr]

Hate to resorect this thread but This TSB title comes up for my 07 and I have not had it done, and I have bad vibes in the 40-50mph range (hopping really). Did this TSB fix it? I've checked my driveline angles and it's kosher. perfect really. Tcase and pinion are the same, and the 2pc shaft is straight with no angle differences. so it's not driveline angles that are causing the vibe. and it only happens at 40-50mph.

to be honest after over a year of it being on....yes/no, it has softened the frequency range somewhat. BUT,
air pressure out back has been the ticket to control but not stop the bouncing and bumpety bump when empty.
i run 35-45 psi on the duals empty.
i would rec. doing the tsb \then play with air pressure to get a flat tread wear pattern without going to low,
when loaded i go back to 75psi out back on each tire

 

[TampaDieselFX4]

Ok, so I'm going to try and have it done one of these weekends coming up. Like I said... I've checked my driveline angles 101 times thinking it was there. I've built custom 4x4's with CV shafts, and custom Toyota/Chevy Driveshafts... so I know how drivelines work very well. My Tcase and pinion are parallel, and the 2pc shaft is straight!! nothing more to do!! I could lower the pinion 2* but that's usually for racing, and High torque soft springs like running rock crawler leafs and 38's with 5.29 gears. Our OEM springs unloaded are huge and stiff. I doubt there is any pinion up play cruising at 47mph. So glad I found this TSB!!! I was going crazy, it's worth giving it a try.

 

[dpantazis]

that be a Tuned Mass Damper.

and they ain't cheap.

i would have liked to have been a fly on the wall to see that fix go up the ladder at FMC.

 

[atk]

i have just learned to live with it, plus i try not travel at that speed....it does help a bit when i do run less psi in the rear tires....

 

[JLDickmon]

that be a Tuned Mass Damper.

and they ain't cheap.

i would have liked to have been a fly on the wall to see that fix go up the ladder at FMC.

it started with a customer being told, "...they all do that..."
and the customer saying, "...then you can fix them all, starting with mine..."

 

[TampaDieselFX4]

It is BS. No reason for a $50k truck to hop like that. I build custom 4x4's in my garage with extreme driveline angles and such and they never did it. I could do over 100 mph in my home grown rigs. so why can't ford fix this technical issue at 47mph? I think they should and can.