Driveshaft vibration and humming in the rear

[Black_Nite]

I have a 2017 Single cab with Inez 4/6 drop with relocating brackets I busted the driveshaft once and got myself a custom one from San Antonio Tx I was able to hit 115mph with no problem now I can’t even go 85+ the driveshaft to the rear vibrates don’t know if it’s the shaft or the rear diff! Anyone had issues of some kind?

 

[NJMOPAR]

Pinion angle might be off. Adjustable control arms might help too.
I'd check the relocation brackets for cracks, I've read about Inez brand having issues.

 

[Black_Nite]

Thanks I’ll go ahead and do that....do you know anything about some sort of baring where the transmission shaft plate goes of it going bad?

 

[NJMOPAR]

Not really.
All I know is anything more than a 2" drop starts affecting pinion angle which will translate into driveshaft vibration.

 

[Black_Nite]

Thanks I’ll check on it

 

[Wild one]

I have a 2017 Single cab with Inez 4/6 drop with relocating brackets I busted the driveshaft once and got myself a custom one from San Antonio Tx I was able to hit 115mph with no problem now I can’t even go 85+ the driveshaft to the rear vibrates don’t know if it’s the shaft or the rear diff! Anyone had issues of some kind?

I'd suspect your aftermarket driveshaft,as it's really the only variable that might have changed,from when you could go 115 to now where 85 is max speed.