Drive shaft failure/Mechanics Special 05DC Refresh

Great tips thank you. All on the list. And I appreciate the HF tip, I've been ITC for years and they already have plenty of my money lol. Talk shit all you want, but I have a store 8 minutes from my house so super easy to swap anything out that has lifetime warranty (I haven't had to much). Their ICON tools are NOT snap on, but for the money for a crappy weekend DIY guy like me they're great.

 

Haven't replaced yet and haven't had time to tinker with the truck much. Spent 6hrs today detailing and polishing my wifes GX, all my projects were on back burner until that got done. It's weird but it looks way worse without the tape measure there, and yes it's only like 0.5"

Will post pics soon. (Don't tell anyone but) I bought quickstruts for it and am planning on installing them at some point in the next week or two. For $150 if they just level it and last a year I'll be happy and revisit the bigger investment of bilsteins later. Again, this truck is being used to go to the dump and hardware store, so I'm not stressing ride or travel much.

 

This interaction of posts has had me domed up for a while now. I have a weird vibration that manifests in the mid 30 mph range, it tapers off as I accelerate but its still there. Can feel it in my seat, see it in rearview, and hear it from my kids carseats (and elsewhere).

I've read a few vibration/driveline threads and I know it can be coming from many places. I have a new (aftermarket) drive shaft, that has one grease zerk that I have filled with fresh grease. I have shitty chinabomb tires and older rusty rims. I have brakes with surface rust that I have no idea when they were last serviced, and I have a parking brake that basically does nothing.

When I was chasing the rear diff leak I filled it with 75-90 full synthetic. I clearly have the goofy brake master cylinder and AUTO LSD button discussed in other recent posts. I'm guessing, then, that I have LSD...sooooooooo is it possible the synthetic fluid in there is causing an issue, and in yalls opinion should I drain and fill with dino? I probably have less than 2500 miles on the synthetic stuff so hoping I didn't do any damage.

 

Auto LSD = open diff with brakes that provide traction control for the rear wheels.

No need to change the synthetic fluid out.