Technical 500X 2.0 140hp 9-speed Auto Transmission Noise Mystery

[G1WLM]

Hi all,

For some time now I have noticed that around 34mph a mysterious sound with a low frequency vibration appears on our 500X. It's as if a component or device comes on and 'spools up' so to speak. At first I thought it was potentially gearbox related but I'm not entirely sure to be honest. Once the noise appears, it appears to remain constant regardless of road speed. As the [road] speed increases, the normal road noise eventually drowns it out and with that, I can't be sure if it drops out all above a certain speed.

One observation I have made is once the noise appears if you knock the gearbox lever over to select manual gears, the noise disappears device as if you have switched off whatever it is. It comes back in again if you bring the lever back across into auto mode. The noise also drops out as the road speed decays but not at the 34mph point, it stays present down to say <10mph although I can't be precise.

The engine and gearbox appear to function just fine in either auto or manual and in any drive mode and there are no other abnormalities apparent. The car is 2016 and has 36K miles on it with main dealer FSH. It is however, infrequently used these days.

I'm curious as to what it might be and might it be something requiring closer monitoring?.

My question to the more knowledgeable community is - would anyone have an idea what might be brought into operation on this model around 34mph so I can increase my knowledge and possibly have it checked out further?

Any insights would be most appreciated.

Thanks
Gary

 

[mortenharboe]

Hi all,

For some time now I have noticed that around 34mph a mysterious sound with a low frequency vibration appears on our 500X. It's as if a component or device comes on and 'spools up' so to speak. At first I thought it was potentially gearbox related but I'm not entirely sure to be honest. Once the noise appears, it appears to remain constant regardless of road speed. As the [road] speed increases, the normal road noise eventually drowns it out and with that, I can't be sure if it drops out all above a certain speed.

One observation I have made is once the noise appears if you knock the gearbox lever over to select manual gears, the noise disappears device as if you have switched off whatever it is. It comes back in again if you bring the lever back across into auto mode. The noise also drops out as the road speed decays but not at the 34mph point, it stays present down to say <10mph although I can't be precise.

The engine and gearbox appear to function just fine in either auto or manual and in any drive mode and there are no other abnormalities apparent. The car is 2016 and has 36K miles on it with main dealer FSH. It is however, infrequently used these days.

I'm curious as to what it might be and might it be something requiring closer monitoring?.

My question to the more knowledgeable community is - would anyone have an idea what might be brought into operation on this model around 34mph so I can increase my knowledge and possibly have it checked out further?

Any insights would be most appreciated.

Thanks
Gary

Hey Gary
I have a 500X 170hp 9 speed with the same problem that you have. The car have been to two Fiat cardealers and a special workshop for gearbox and transmissions repairs. No one could find the problem. They chaanged the Oil in gearbox and rearaxel. It didn’t really help.

Did you find a solution or?

Best regards

Morten
Denmark

 

[ridders]

well known problem with the renegade that shares the same ZF transmission/drive chain
there is extensive discussion here:

https://www.jeeprenegadeforum.com/threads/grinding-vibration-rumble-noise-at-30mph.28737/

 

[G1WLM]

Hey Gary
I have a 500X 170hp 9 speed with the same problem that you have. The car have been to two Fiat cardealers and a special workshop for gearbox and transmissions repairs. No one could find the problem. They chaanged the Oil in gearbox and rearaxel. It didn’t really help.

Did you find a solution or?

Best regards

Morten
Denmark

Hello Morten,

Apologies for not replying sooner. I haven't yet found a solution. The link to the jeep renegade forum kindly provided by the other contributor to this thread provides much more insight to the problem. There is so much information on that thread that it's hard to find that one person who has provided the summarised solution. It would appear that FCA struggled to acknowledge that a problem exists however the general concensus is that it is related to the rear drive unit not properly disengaging it's wet clutch system to switch off the propellor shaft and drive to the rear wheels once speed reaches 34-39mph. Contrary to my original and limited understanding, moving the gear lever across to manual or selecting sport mode actually brings back in the propellor shaft and drive to the rear wheels and not switching something off as I first thought. In summary, the noise and rumble only appears to be present when drive to the rear wheels via the propellor shaft has been disengaged, not engaged. I'm still working my way through the information in the jeep forum and hope to find out more that way. Best wishes, Gary

 

[G1WLM]

well known problem with the renegade that shares the same ZF transmission/drive chain
there is extensive discussion here:

https://www.jeeprenegadeforum.com/threads/grinding-vibration-rumble-noise-at-30mph.28737/

Thanks for sharing this forum thread Ridders, it's a very helpful information source. Much appreciated.