2002 F250 Short bed crew cab 4x4 automatic.

I've recently noticed a bearing noise that corresponds with speed, not rpm's. I believe it is the carrier bearing as I can wiggle the driveshaft pretty easy in it. How do you tell if it is that or if it is a wheel bearing and which wheel bearing it is?

Thanks

 

The easiest way to check the bearings is to lift the wheel off the ground and check for lateral (both horizontal and vertical) movement by pushing firmly. Any movement is unacceptable and further inspection should conducted. On 4x4's the Front Bearings are part of the Hub Assy.

 

I had mine put on a lift and run up to 60 MPH. I could stand under there with a mechanic's stethoscope. In my case, it was a bad carrier bearing, front-left axle bearing, and a spun pinion bearing in the differential. There were too many to troubleshoot on the road alone.

 

There should be no "wiggle" in the driveshaft, so definitely fix that. Infrared heat sensor can tell you whether the pinion is a problem, about 120 degrees on a moderate day is a typical temp. for the pinion and wheel bearings (unless doing hard braking). U-joints are another obvious source of vibration. If it was me, I would fix the obvious, then if there was still a problem, take it to a driveline shop for further diagnosis.
Those unit bearings up front can be sneaky, but the infrared should show excess heat after even a short 5 mile drive.
Larry

 

Ok, I'll fix the carrier bearing and hope for the best. I'm not good at determining from which way the sound is so jacking and wiggling or temp gun use is good info for me. Thanks.

Follow up question on carrier bearing. Doing some shopping online, I see there is two different sizes to choose from. I would like to have the new bearing in hand before I disassemble the truck. How do you tell which size you have?

Sorry if these are elementary questions, I've never had to do any involved work on this truck until now. Gotta put in the remote control remote receiver and have that programmed too.