How's it going guys,

I've got a 99 Suburban LT 5.7 with 298,000 on it and for the past thousand miles or so there's been a rough shaking coming from what feels like the transmission or driveshaft. I've been digging through the forum as well as Google and see a lot of similar-sounding problems, but they are all occurring at highway cruising speeds, while mine goes away after I speed up. I notice it especially when I'm rolling backwards in reverse or when I'm idling with my foot off the gas completely. Sometimes it actually seems a little bit worse if I'm turning the wheel, and I have also yet to try it in 4WD. It's somewhat intermittent and for the most part seems to go away after the car has warmed up some. I JUST flushed my transmission about 2 weeks ago, hoping the problem would go away.

Is my tranny about to drop? I sureee would appreciate some advice.

Thanks everyone!

 

I'd look at the rear diff.

 

x2

 

much obliged