Got a noise I can't track down - Diesel Forum

Cylinderhead1 · 05-26-2009, 09:10 PM

My '99 F550 (7.3/6spd) makes a groaning type noise between 58-63 mph. I thought it was either the drive shaft or rearend. So far I've replaced thepinion bearings (which were showing signs of wear) and I've had the driveshaft balanced along with new u-joints and carrier bearing. The slip yoke does have some play in it but I'm not sure how much is exceptable. There is no viberation, just alot of noise. Loud enough to make it almost unbearable. I've spent hours under the truck and can't find anything.
Any thoughts?

RatherBNtheWoods · 05-26-2009, 09:29 PM

Is it a whine, a growl, or a rump rump rump?
Is it the same at cruise as it is accelerating and/or decelerating(not braking just foot off of the go-pedal in gear clutch out)?

Does it make the same noise with the gearbox in N coasting at 60ish?
Was anything done just prior to the noise starting? ie: Repairs, hit something, loaned it to the neighbors crackhead son?

Who did the pinion gear bearing R&R? Did the noise change any at all?
What condition did the other diff bearings look to be?

Cylinderhead1 · 05-26-2009, 10:27 PM

It's deffinately a growl. I just recently bought the truck and it has 127k miles on it. I had the rearend done at a reputable heavy truck shop. All the bearings in the rearend were checked. I saw the pinion bearings and they were pitted plus the pinion seal was leaking. Reason for having the pinion bearings checked.
The growl is more prominent when on the go pedal and if you push the clutch in it's still there but no where near as loud. Also when going down hill and off the go pedal the growl is less.

uhaul · 05-26-2009, 10:41 PM

I had a steady groan from my diff. and I found that the diff. side bearings were spining on the surface they were supposed to be pressed onto, they fell off when I pulled gear out and shouldn't do that. also the side shims were blue and squeezing out so I had to replace whole rearend. also check if you have an anti-lock brake sensor in top of diff. maybe its rubbing the ring inside of housing? if all fails, do a contact pattern test on ring&pinion.

RatherBNtheWoods · 05-27-2009, 11:21 AM

Quote:

Originally Posted by Cylinderhead1

It's deffinately a growl. I just recently bought the truck and it has 127k miles on it. I had the rearend done at a reputable heavy truck shop. All the bearings in the rearend were checked. I saw the pinion bearings and they were pitted plus the pinion seal was leaking. Reason for having the pinion bearings checked.
The growl is more prominent when on the go pedal and if you push the clutch in it's still there but no where near as loud. Also when going down hill and off the go pedal the growl is less.

Hum. A tuff one.
The driveline has been rebuilt and balanced.,,,A growl that's worse under power and less when not under power, if not the driveline, I normally would say ring&pinion gear pattern/lash would be suspect.,,,But if the noise was there before and after the shop was in it,,,,....Hum...

Maybe have the shop run it while on the lift/rack and look/see/listen.

If all else fails, and I really wanted it to stop and I was going to keep the truck for a while, at 127K miles I would replace every bearing in the rearend and the gears. Wheel bearings, carrier assembly bearings, pinion gear and bearings and the ring gear. New clutches if it is a LS diff. Have a shop/tech that is knowledgeable and experienced on that particular diff set it up/do the work.

Cylinderhead1 · 05-27-2009, 08:51 PM

I'm not ruling out the slip joint yet. Like i said it does have some play in it. I bought it just to pull the race car around. I might put 6k miles a year on it. And combined weight (truck and everything behind it) is right at 19k lbs.