Rattling noise is coming from the driver-side front

[gpeters]

For about a month now, I have been hearing a rattling noise on my 2017 RAM 1500 ECO diesel. I don't think it is the engine because it is not a bottom-end knock like these ECO diesels are known for when the engine fails (I've been there already)

It is not constant and I hear it the most at 70-80 km per hour when the truck is under light load. It sounds like something is rattling/flapping, and when accelerating it goes away. Also when driving at about a 100 km per hour I don't hear it. It is slowly getting worse.

Yesterday I checked under the truck and noticed that there is play in the left-hand front shaft from the axle gearbox to the wheel. The play is by the gearbox. Could this be it? What else should I check for? If it were constant, it would be easier to find.

 

[rzr6-4]

Yesterday I checked under the truck and noticed that there is play in the left-hand front shaft from the axle gearbox to the wheel. The play is by the gearbox. Could this be it?

Very well could be your CV axle. If you don't know how to pull it apart yourself to verify/replace, take it to a mechanic. Driveline components are not your friend when they undergo spontaneous self-disassembly.

I had a U-joint go from no noise, no vibration to horribly noisy and afraid to drive it across the yard in about 10 miles.

It may not be your CV, but you definitely need to look closely at it and don't put it off.

 

[gpeters]

I just recorded two shorts on both sides. The joins feel solid, but there is play on both sides where the axle goes into the gearbox

Left-hand side https://photos.app.goo.gl/QMf4iBdPxH82PmFE7
Right-hand side https://photos.app.goo.gl/dRFEtTkFweZBbHpj7

 

[rzr6-4]

I just recorded two shorts on both sides. The joins feel solid, but there is play on both sides where the axle goes into the gearbox

That is certainly more rattling than I would expect but I’m not as familiar with the 1500s. Perhaps someone else will come in.