4x4 Noise?

[Murf]

While towing a 9,000 lb trailer today, I encountered some snow and put it into 4wd - it develops a wierd kind of hum/whine around 2200 rpm when I accelerate and goes away around 2300 or so. It does not make the noise in 2wd - have 15,000 miles on it, have not done hardly any 4wd miles either on or off road - wonder if its breaking in or what? Anybody else ever heard this?

Thanks - Murf

[dieseldummy]

Murf,
I beleive that there have been some TSB's on this subject, i'm not sure but your dealer should be able to look them up and help you out.
Justin

[saywhat]

Probably a little vibration,not at all uncommon when in 4WD at highway speeds.Your front and rear differentials are not perfectly matched,tires might not be either.By all means,have dealer look it over if it seems to be excessive.

[Murf]

Figured it out - the rear tires had worn more than the front - found some hardly used exact replaccement tires put them on and howl gone - the dealer figured it out and on my way home dropeed by Big O and they had a set of trade ins in the back - they wore down in the back from 10,000 miles of constant towing and no rotation - guess I'll rotate now.

Murf

[tanker]

Many people don't rotate tires, but here is a good reason to rotate every 5000-1000 miles. Tire pressure is also overlooked. Correct pressure on our trucks is more of a science than it is for passenger cars. I inflate more when towing, then drop pressure when not. Our various loads require different pressures. This will also prolong tire life.
Murf, you were lucky to find a good pair of take-offs that matched your fronts. Sometimes we can make a good deal on take-offs. I found a new set of 265's at my local tire dealer. He took them off a new Dodge. The guy drove from the dealer to tire shop, to increase the size. It pays to shop and look around. smile.gif