Grinding sound when accelerating uphill from a stop.

2013 DCLB 4.0L 4x4 78k miles

Truck runs great except I have noticed this grinding sound in this specific situation (accelerating uphill from a stop or very slow crawl). It occurs for a second or two then stops, it doesn't seem to me to be in time with the transmission shifting so I don't think it's that.

It was worse before and I checked the oil. I use Castrol Edge full synthetic and change every 6-8 months. Oil looked dirty so I changed it early about a week ago. Grinding sound improved substantially but I can still hear it for a second if I push the car a little when going uphill.

What could this be?

 

I seriously doubt it has anything to do with the engine oil...

I would be checking the drive shaft universal joints and carrier bearing. Pull the rear driveshaft and manipulate the three universal joints and bearing. If any u joints are stiff dry or floppy replace them all. If the bearing is loose or squealing replace it too.

 

Thanks a lot. I will start looking into these. Appreciate the help!

 

Spark knock or possibly a heat shield rattling?

 

Ok thanks. I'll check those.

A little more info: i drove around just listening for it and trying to replicate it. It seems to only happen when trying to accelerate slowly and ONLY at 1800-1900rpm. As soon as the needle gets to 2k it stops. If I time it just right around 1700rpm and give the accelerator a little extra gas to "skip" through 1800&1900 then I don't hear the sound at all. But if I accelerate normally and try to hold around 1800 then it will continue.

 

from what area does the sound seem to be coming from?

 

To me as the driver it sounds like it's coming from underneath the truck. It doesn't sound like it comes from the engine compartment if that makes sense.

 

your description points to possible heat shield loose

 

Appreciate your time. I will check!

 

So I poked around under my truck but could not locate any issues. I bought a grease gun to grease the driveshaft because I read that needs to be done and I haven't done it.

I took a video of the sound today. Sorry for the potato quality my phone is old. Hope these work...
https://photos.app.goo.gl/uAMsQ6eJKGaKtC2n9

https://photos.app.goo.gl/UZjPWmzVbJSH1pQG6

I have a couple more videos too if anyone thinks they'd be useful but this was the shortest one I could clearly hear the sound.

In the vids I specifically tried to keep the rpm just under 2k to make the noise more apparent.

 

Drive Shaft, pull it and inspect the joints and bearing.

 

Do you think greasing it may make it better or do you think I should just pull the whole thing and replace all the u joints and carrier bearing? Is that kit on eBay any good as far as you know?

This would be a doable but very large project for me.

 

I'd replace them all and forget about it. At least you will know you have all new joints and a new bearing. If they are making that noise, grease is only putting off the inevitable.

 

Ok thanks. Guess I'm renting a bearing press!

 

After you get everything changed out, keep up to date with maintenance on the joints. Lots of members on TW grease them with every oil change, myself included. Look into purchasing a grease gun if you do not own one. I just grease them until I stop seeing old grease and start seeing the new grease come out. Good luck!

 

Thanks. Way ahead of you. I boght a grease gun and fresh #2 red grease. I have owned the truck for 1.5 years but didn't drive much during Covid. Now that I'm driving more I am researching more maintenance. One thing nobody ever told me was grease the driveshaft but I saw it here right away. I also saw a video on YouTube about it and bought the gun and zerk attachment on Amazon.

I'm tying to be more handy this year and do things myself. Bought all the stuff for differential and transfer case oil changes as well. Got the list from the sticky on here and am trying to go down the list one by one. Spark plugs seem like the most work.

 

Sounds like you are well on your way, sir! Sparks plugs aren't terrible, take your time and follow the how-to thread on here. Advice for the diff and tx case, make sure you can remove the fill plug before taking the drain plug out. They can sometimes be a bear to remove.

 

Probably hearing axle wrap

 

Greasing may be a short term patch. What I am saying is the only way to Know if the bearings or center bearing is worn out is to remove the drive shaft and inspect it.

 

I am preparing to do that. It's going to be a big project for me. Based on the videos I have found I think it's doable. I figure even if the joints aren't fucked I will replace them all since I will have it out and I should learn how to do that.

In preparing I've been looking at the driveshaft. Does the stock OEM driveshaft have a Spicer sticker/label on it that says "Do not service this driveshaft without rebalancing" with a barcode and other information?