Rumbling noise on turning 2017 exp LTD EL

[jeff kushner]

I appreciate your input 16 but I do not need "clutch packs", nor did you in all likelihood. One DOES need to look at a blowup of the rear differential to understand.

I have a tiny bit of experience when it comes to this stuff....I'm good.

If in the future, I prove to be wrong, I'll admit and own it.....but I doubt that will be the case.

jeff

16,
I truly hope that your dealer was honest to you but knowing that most dealers only employ a single master mechanic and a bunch of parts changers, I would wonder who would have had the skill-set at a deal to replace them?

I'm curious since I honestly thought they were BS'ing you when you were told they had replaced them.....did you look at the assembly bolts of the rear to see if they had been removed & replaced? A 2016 will easily show if it was really taken apart but you will have to look close because often, lube is sprayed but no bolts was actually undone...they do it as a "show".

 

[16plati]

I appreciate your input 16 but I do not need "clutch packs", nor did you in all likelihood. One DOES need to look at a blowup of the rear differential to understand.

I have a tiny bit of experience when it comes to this stuff....I'm good.

If in the future, I prove to be wrong, I'll admit and own it.....but I doubt that will be the case.

jeff

16,
I truly hope that your dealer was honest to you but knowing that most dealers only employ a single master mechanic and a bunch of parts changers, I would wonder who would have had the skill-set at a deal to replace them?

I'm curious since I honestly thought they were BS'ing you when you were told they had replaced them.....did you look at the assembly bolts of the rear to see if they had been removed & replaced? A 2016 will easily show if it was really taken apart but you will have to look close because often, lube is sprayed but no bolts was actually undone...they do it as a "show".

Cover had been cleaned, I have all new rear diff cover bolts and new rear diff sealant. I saw the old plates next to new ones and could see exactly what was happening inside the rear diff. I requested their master mechanic and they gave him the job without hesitation. He is the guy who does rear end specific jobs at my dealer. I know they put the modifier in with the gear lube bc it smells like shit now. They did a full service and didn't jip me at all. I have a parts list of everything they purchased and installed

 

[jeff kushner]

That's fantastic....I had seen the receipt.....you really have a fantastic dealer...congratulations! Not often we see this!

The Additive isn't the source, it's almost oderless....it's the moly in the grease...horrible super-strong sulfur-like smell right? Wasn't in the original fluid either I noticed when I poured it from the pan to the big container. It's an excellent lube however customers don't like bad smells so maybe that's why it wasn't used...I don't know.

Again, glad you're all fixed and happy.

jeff

 

[Erzebet]

Yeah I just got upgraded carbon fiber packs, fluid, and modifier all under warranty. Smooth as butter now

I so wish my dealer was like yours. I have the same shudder/rumble symptoms at slow turns from a stop (pulling away from curb or out of a parking space) as described in your thread(s) on my '16 EL with 46K. It started in March. Three visits later , and after checking the front end and the brake system they still can't find anything wrong.

I want to try a different tactic. Instead of asking them to to troubleshoot the symptoms I describe (which has gotten me nowhere thus far), I want to bring it back and ask the Service Adviser to check the clutch packs. Can the mechanic/technician tell if the clutch packs are the culprit just by looking inside the differential or by draining the fluid? Is there a TSB, or something I can refer them to for the symptoms? How did they refer to your clutch pack repair on the invoice? If I have to use your experience for them to seriously consider the clutch packs as the source of my issue = I will. I just want this issue fixed. Thanks for any advice you can lend.

 

[aagitch]

Am I correct that the shudder/rumble would pertain to the limited slip rear. I don't have this issue but was just curious. Mine isn't limited slip anyways.

 

[16plati]

I so wish my dealer was like yours. I have the same shudder/rumble symptoms at slow turns from a stop (pulling away from curb or out of a parking space) as described in your thread(s) on my '16 EL with 46K. It started in March. Three visits later , and after checking the front end and the brake system they still can't find anything wrong.

I want to try a different tactic. Instead of asking them to to troubleshoot the symptoms I describe (which has gotten me nowhere thus far), I want to bring it back and ask the Service Adviser to check the clutch packs. Can the mechanic/technician tell if the clutch packs are the culprit just by looking inside the differential or by draining the fluid? Is there a TSB, or something I can refer them to for the symptoms? How did they refer to your clutch pack repair on the invoice? If I have to use your experience for them to seriously consider the clutch packs as the source of my issue = I will. I just want this issue fixed. Thanks for any advice you can lend.

Only way to know is if the truck shutters and rumbles when you turn under power at low speeds. They won’t open it up just to open it they will ask why u want to open it and if it ends up being nothing now your paying for diagnostic fee and a rear diff fluid exchange

 

[16plati]

Am I correct that the shudder/rumble would pertain to the limited slip rear. I don't have this issue but was just curious. Mine isn't limited slip anyways.

Correct. LSD

 

[Cynthia2963]

Hey all, thanks for your suggestions! It turns out it was the differential! Thank goodness for warranty!

 

[turtle019]

Thanks for the great info y'all! I was having the same problem and just got my clutch pack replaced and friction modifier added under warranty. Silky smooth now

 

[Greg S]

Hey all, sorry I'm late to the party but just experienced the same issue after changing my rear differential oil at 99K miles, also lifted my truck with the 3/2 ReadyLift kit, new struts and coils (KYB Strut-Plus), and new BFG All Terrain KO2 tires, within about a month timeframe. I had always noticed a slight vibration when turning hard to the left or right at low speeds, but it seemed to get worse. I initially thought it was due to the new tires and their aggressive tread gripping the road, but came across this thread and realized that when I changed the rear diff oil, I didn't put any of the Motorcraft XL3 friction modifier. I used Mobil 1 75W90 gear oil which advertises to have an LSD additive, which is why I didn't add it to begin with.

After reading this, I ordered a bottle of the XL3 off of Amazon. When it arrived, I removed about 12oz of the new gear oil from the fill plug with a fluid pump, discarded it, mixed the contents of the 4oz bottle with 8oz of fresh Mobil 1 gear oil, and added it to the rear differential, and reinstalled the fill plug.

After driving the truck for about 150 miles over a 3 day period, the vibration got much better and is about 90% gone at this point. I figure that the remaining minimal vibration is due to the lift combined with the wheel offset (5.5" of backspacing) and tires, so I can live with that.

Just wanted to share my experience as well, as it seems that many of us 3rd gen Expedition owners have this issue and there are many different theories out there...the $10 bottle of friction modifier and 30 minutes of time to add it to my already new gear oil solved the problem.