Drone at 94 km/hr

[Bunkboy]

Just got my truck back (04 LLY Crew Cab S/B) from the dealer to find that changing the entire exhaust system did nothing for the droning noise it was supposed to address. I noticed on other sites that some guys with a similiar noise had weights attached to the exhaust pipe and it helped.

The truck has a droning noise that appears at about 94 km/hr and goes away at about 100 km/hr, it is louder in 4x4. If you let off on pedal it quiets down and it goes away after 100 km/hr. I have had it at the shop several times but still no remedy. A co-worker has the same truck with the same problem and his dealer told him they have several trucks with the same problem but no idea how to resolve it. I am down to a little more than 1 yr warranty and my patience is getting thin...

[DmaxMaverick]

Two piece drive shaft, or single?

If two piece, I'd start looking there. Could be a shaft out of balance, U-joint(s), but more likely, the carrier bearing and/or the insulator.

[Roy W]

Mine has done it at 58 mph since brand new, so that potentially eliminates driveline wear, etc. I heard that there is a TSB on this and that they install a short flex or bellows type section in the exhaust that is supposed to eliminate it, but I haven't heard of anyone having it done.

[Deansel]

I have heard the same thing from our dealer about the use of a flex-coupler. I will have our truck in for service in the coming week and they are supposed to look at the exhaust noise then.

Update: service manager said that there is a TSB out on the problem and they ordered a new CAT and muffler for our truck, they should have it in a week or so. I will let you know if it solves the problem.

[ 01-06-2006, 01:02 PM: Message edited by: Deansel ]

[Deansel]

Bump