Need help with trying to decide where noise is coming from.

[hvillem1009]

I was driving my M1009 home from work yesterday, and I started noticing a loud roaring noise whenever I would let off the gas pedal and start braking. When I would give it gas, the noise would go away. It progressively got worse the closer I got home. The roaring noise is only there when I let off gas to slow down. As long as I am applying gas the noise is not there. Any ideas would be appreciated.

 

[Recovry4x4]

Loose air cleaner???

 

[hvillem1009]

I have checked the engine compartment and transmission, but don't see any obvious signs of anything wrong. I checked the fluid levels in the front/rear differentials and they are full.

 

[Recovry4x4]

Perhaps you should have told us all the things you've checked instead of telling us this after we offer suggestions.

 

[doghead]

Look close at your starter support. Check if it is tight.

The throttle cable can vibrate, check the bolts on that bracket.

And the air filter housing , as Recovry said.

 

[hvillem1009]

Ok. I checked the air filter housing and one of the top bolts was loose, so I tightened it. Checked the belts, battery supports and power steering fluid. Found out the power steering pump is out of fluid. Would the pump being out of fluid make that much noise? I also checked the starter bracket, it is still tight. I just recently had to replace started bolt that broke, checked those and they are still tight. Thanks so far for the suggestions, if you anymore let me know.

 

[Coffey1]

Check u joints my truck was doing same thing weird noise when off throttle gone when throttle up

 

[Coffey1]

Also check front Axel hub bearings and front Axel u joints . They look OK but could be dry

 

[hvillem1009]

What is the best way to check the universal joints? I greased them probably about 5 months ago, but have only driven maybe 1000 miles since then.

 

[Coffey1]

Take apart and do a inspestion. Don't lose needle bearings. They like to jump out when you pull caps on joint

 

[Hasdrubal]

Never had a loud roaring type noise from u-joints. Usually its a high pitched squeek as the needle bearings get ground into dust. The driveshaft u-joints can be inspected for play manually by hand, will be quite apparent if they're shot. The front axle u-joints can also be checked by hand, if they're gone, you'll notice that they bind.

 

[86m1028]

how did the rear diff fluid look ?

ring & pinion ?

 

[m1010plowboy]

The first time I heard my engine fan in the M1010 I thought I ran over a freight train. Had the stereo down or the wind was blowing the right direction but I thought I was doing it backing off on the gas until the hmmmms turned to aaaa ha. Just the fan kicking in. When I let off the throttle to slow down, the hammering 6.2 was quieter than the fan. How hot is it there?

After everything else, eliminate the probability of pulley bearings by loosening belts and spinning everything by hand. Strange noises suck.