Howl, 60-70 MPH

[tvoymang]

I have an 01' F250, just had a bearing job done on the rear end. The guy has done work for me before (i trust him), he checked it out and said the gears looked great just a failed support bearing causing a BAD howling noise. Got the truck back last week and I am still noticing a howl, but a different one this time. It starts around 60mph, getting its loudest around 65 mph, and by 70mph it has dissapated almost completely. If I let off the throttle, the noise goes away all together. It is pretty loud. No vibration, truck drives nice.. I am thinking U-joints or possibly carrier?

Opinions?

[timmyboy76]

subscribing....have been fighting same sound ,but mine kicks in at 1300-1800 rpm band. I've thrown a folied cac tube, new/rebuilt turbo, stuffed rags in fender holes...you name it, i've done it. Happened after rebuilding firstturbo when it popped, get'n on it, on the freeway. Been a year now. But like you said, let off pedal, noise goes away. I'll throw it in N, and rev motor to 1500-ish rpm, and CAN NOT replicate noise...?

[don't ram it, stroke it]

Sounds like carrier bearing to me...you can easily check for a bad carrier bearing...... to check the rubber bushing first, just push up and down on the shaft and see if there is any play in the shaft....(when the rubber bushing is bad truck will clunk when taking off from green light, or putting into gear.) to check the bearing, Just take the 2 bolts out of the carrier support and spin the whole assembly around, and wiggle back and forth to check for bearing play. have the old bearing pressed off and new bearing pressed on...You can also cut old bearing with a grinder and metal cutting wheel then cold chisel and hammer to crack inner race, then using a piece of pipe to slip over the yolk, hammer new bearing on.....I don't suggest heating/torching the old bearing to beat it off because this heats the tempered metal on the yolk and makes it brittle. seen many drive shafts fail and break at the heated spots using this method!!!

[Greenman01]

Sounds more like a pinion bearing to me. Bad side bearings would make noise at all times while a pinion bearing will typically only make noise under load.

[tvoymang]

Like stated in the OP, i JUST had a bearing job done on the truck... and when i say just, i mean less than 1k miles ago. I am also leaning towards carrier bearing/u joints, so will definitely respond with results when i get around to replacing them.

[Greenman01]

I am not understanding what a support bearing is. If you are sure it is coming from the rear then chances are it is still the pinion bearing. Perhaps preload was not set correct.

[don't ram it, stroke it]

Originally Posted by Greenman01

I am not understanding what a support bearing is. If you are sure it is coming from the rear then chances are it is still the pinion bearing. Perhaps preload was not set correct.

Carrier bearing is where the two drive shafts meet...

[Greenman01]

Originally Posted by don't ram it, stroke it

Carrier bearing is where the two drive shafts meet...

Never heard that term used for it before. I am only familiar with steady bearing and center bearing. Anyway, the steady bearing is not your issue. Make sure your driveline was properly phased.