Occasional vibration?

[Horse_gal_jen]

In our 2001 duramax we can feel an occasional vibration in the floor but not the steering wheel when driving above 60 Km/h and it seems to be worse when lugging or pulling a load. We are wondering if the cause might be a U-joint of if we should check out some other causes.

[Runaway_Dmax]

U-joints or if a long bed truck it may be the center carrier bearing on the drive shaft. Found on two-piece driveshafts.

[christophersond]

In our 2001 duramax we can feel an occasional vibration in the floor but not the steering wheel when driving above 60 Km/h and it seems to be worse when lugging or pulling a load. We are wondering if the cause might be a U-joint of if we should check out some other causes.
You didn's say, but I assume your truck has the long bed, 2 drive shaft configuration. If so, you probably have the dreaded frame beaming problem. Suggest you checkout TSB # 1844688, and see if it describes the symptoms. If so, you will be disappointed to learn this is a characteristic of these trucks, and there is no fix.:mad: I had an 07 GMC Classic with this problem. The dealership tried pinion angle shims, new drive shaft, etc., to no avail. The vibration persisted, and was quite noticeable between 55-65 MPH while towing my 5th wheel. After tiring from my wife's commentaries on the vibration, I eventually traded it in on a new short bed truck--problem solved!!

Chris