Is this a ring/pinion noise? Or what? Loud "ring" ONLY @ 75mph under slight load!
04-07-2017, 08:33 PM
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Model: Cherokee
Is this a ring/pinion noise? Or what? Loud "ring" ONLY @ 75mph under slight load!
I have a 2012 Grand Cherokee Overland with the 5.7 Hemi. It now has 85,000 miles but this ringing/whining noise started back at 55,000 miles or so. What’s happening is a loud ringing noise ONLY at 75mph and ONLY when under SLIGHT acceleration. It does NOT do the noise under 73 or over 77. It does NOT do the noise when coasting or going on a flat or downward slope. But since I usually have the Adaptive Cruise Control set for 75mph, as soon as the ACC adds just a slight amount of power the whine picks up again. It’s almost at a decibel pitch level that’s high enough to be considered a “rrrrrriiiiiinnnnnngggg” that really gets into your brain. And very annoying. If I accelerate hard, then the noise disappears. So it is strictly at 75 and strictly under a slight acceleration loud.
Now here’s the tricky part. Because of unrelated issues, Jeep has already replaced the following:
-Automatic Transmission
-Trans Kit w/Torque Convertor
-Trans Cooler & Condenser
-O2 Sensors
-Driveshaft, Transfer Case to Rear Axle
-Replaced Rear Prop Shaft
Still, after all of that, the noise is still there just like before even with all of the above work done. I was told by the owner of a heavy-duty truck transmission manufacturer that the Ring & Pinion should be checked “as it might be set wrong”. Does this sound correct to you?, or can you determine form these comments if there’s a more likely suspect? I know the Jeep mechanic is a perplexed as anyone and he says the pinion “looks” OK, but might it be an adjustment, or (from what I’ve picked up) the “angle” or degrees, that needs to be adjusted? Is there a certain component that would show wear specific to 75mph? I drove with the expert Jeep trans mechanic sitting in the back seat and he instantly heard the ringing whine and found it coming from the center-line tunnel right behind the front seats. BTW, it is clear it is not some unrelated thing like the roof-rack, windshield, or some other such nonsense. It is clear it’s a driveline issue of some sort, a bearing, bushing, (rear differential?), etc.
Any suggestions?
Now here’s the tricky part. Because of unrelated issues, Jeep has already replaced the following:
-Automatic Transmission
-Trans Kit w/Torque Convertor
-Trans Cooler & Condenser
-O2 Sensors
-Driveshaft, Transfer Case to Rear Axle
-Replaced Rear Prop Shaft
Still, after all of that, the noise is still there just like before even with all of the above work done. I was told by the owner of a heavy-duty truck transmission manufacturer that the Ring & Pinion should be checked “as it might be set wrong”. Does this sound correct to you?, or can you determine form these comments if there’s a more likely suspect? I know the Jeep mechanic is a perplexed as anyone and he says the pinion “looks” OK, but might it be an adjustment, or (from what I’ve picked up) the “angle” or degrees, that needs to be adjusted? Is there a certain component that would show wear specific to 75mph? I drove with the expert Jeep trans mechanic sitting in the back seat and he instantly heard the ringing whine and found it coming from the center-line tunnel right behind the front seats. BTW, it is clear it is not some unrelated thing like the roof-rack, windshield, or some other such nonsense. It is clear it’s a driveline issue of some sort, a bearing, bushing, (rear differential?), etc.
Any suggestions?
