2008 SLT 4x4 128,000 Miles.
Brought to the dealer (Autonation on Broadway that used to be Brandon Dodge) because of a whining noise coming from underneath which the tone of the noise rises & falls with increased or decreased speed. Noise started maybe 3 weeks back and got progressively louder. 2WD or 4WD makes no difference but it sounds like gear whine. Only took it to the dealer because of lifetime warranty. After making an actual appointment, the truck still just sat there for 3 days before they even got to it.

Here's what they did:

Seapage (they can't spell) at TCASE tighten & clean area.
Front diff leaking replaced: Seal-Axle Drive shaft 52069706AB & 52114377AC
Shaft-Axle Half R5170822AA (That was just replaced TWICE back in October. Guess they don't make 'em like they used to)

Picked up today and it's making the exact same noise. (This is the same dealer that last time said the truck was "behaving normally" when the temp gauge was swinging back & forth like a compass needle) Do the technicians even test these vehicles before they pronounce them "repaired"? How do they send a truck out the door that has the exact same symptoms as when it came in the door? Is there anyone here that is actually a tech at a dealership that can explain to me the process that allows that to happen? (I'm not being sarcastic, I'm truly curious)

1. Any thoughts what it may be? It seems the dealership is incapable of correctly diagnosing the problem so maybe someone here will have an idea I can suggest to them when I take it back.
2. Does anyone near me know a Dodge dealer with a decent service department? Does such a thing even exist anymore? I live near Castle Rock, CO. I have had the truck at Autonation on Broadway (formerly Brandon Dodge), Castle Rock Dodge, (which used to be Medved) and Autonation Ram on Arapahoe and same kind of crap has happened at all three. The widespread incompetence is hard to believe. I'm truly not being a nitpicky customer, all these places have done the same type of thing. Say "Yep, all fixed!" when the exact and obvious problem the truck was brought in for still exists and is completely unchanged.

Sorry to rant guys. Just so dang frustrating. Thanks upfront for any thoughts.

 

Go back to the dealer, explain to them that they didn't fix your problem, and suggest you take someone for a ride, and SHOW them what you are talking about. When I worked as a service writer at the dealer, I found that to be the BEST way to discover exactly what it was the customer was complaining about, and we didn't get these types of situations.......

 

Take a look at the underside of the truck where the drive shaft connects to the pinion; is underside of bed and back of gas tank coated with black gunk?
If so, that would be a pinion seal and we can discuss more if you see this.
Also could be wheel bearings or something with brake pads or shield.

 

Is it directly related to vehicle speed or engine speed?

 

"Go back to the dealer, explain to them that they didn't fix your problem, and suggest you take someone for a ride, and SHOW them what you are talking about. When I worked as a service writer at the dealer, I found that to be the BEST way to discover exactly what it was the customer was complaining about, and we didn't get these types of situations......."

That is what I did this morning. The tech went for a ride with me and heard the noise before we had even gone 20 feet in the parking lot. He said it sounds like rear diff but might be wheel bearing, etc. He and the service manager both said they didn't hear the noise before which I find very hard to believe because it was not intermittent or hard to hear at all. In any case, we'll see what they say and I'll report back. The tech asked what kind of fluid I had in the rear diff and I told him Royal Purple 75W-140 Gear Oil + 4oz of Mopar Limited Slip, just like the owner's manual says. I don't believe they can void the warranty just because it's not Mopar Brand fluid. But they may try.

 

Vehicle Speed.

 

Too late as I already dropped it off again. But I know they have already replaced the rear pinion seal where the driveshaft connects to the rear differential twice now in the last 2-3 years, the last time was less than a year ago. But it was never making any noise before, they just noticed a leak the first time, and I noticed it the 2nd time.

 

Do you know how low your diff oil level got when the pinion seal was leaking? Pinion seal leak can cause the front pinion bearing to fail and make the noise you describe (at least the way I am imagining your noise). If your pinion bearings are making noise the only fix is to replace them.

 

I don't know for sure how low it got. I didn't see any driveway drips either time, nor did I notice any black gunk that had been flung as described in your earlier post. I know after the first time, the dealer recommended I change the fluid because it was "discolored" (which may have just meant "purple") but they did not say it was "low". I did change it at that time but I didn't measure how much came out. I don't recall feeling any surprise or consternation about a low amount of fluid coming out when I did it.

But I'd bet you may be correct about the problem. With two pinion seal leaks happening in a fairly short time frame, it wouldn't be surprising if the bearing suffered some excess wear.

Thanks for the input!

 

Here's the update, and thank you guys for the input.

Dealer just called and said there is some wear to the rear diff pinion bearings and also to the internals. Full rebuild of the rear diff + new axle shafts as well. All covered under drivetrain warranty.

So I am pleased that it sounds like the problem will be properly addressed, just wish I wouldn't have had to go to the rigmarole of picking up an "unfixed" vehicle only to have to take it back the next day.

For future visits, I'll plan to always take Hey You's advice, and take the tech for a drive so they can witness the problem 1st Hand.

Blood Pressure falling back to normal levels.