Dump truck shaking, only when loaded

I tried to see if there was any play in the splines, they seem tight to me. The U-joints are tight, the one I replaced was a Spicer brand. I hear you on spending money on chasing a vibration, this ones just driving me nuts and something is out of whack lol.

 

That I have not, I'll try and check it out next time I have a full load on it, thanks

 

Not sure what you mean? The two pics are from the same truck. Front shaft has carrier bearing, rear has slip yoke.

 

I did find a driveline shop near me, going to give them a call Monday and see if the can check out the driveshaft, at least rule that out of looks ok and is balanced.

Thanks, will update

 

Couple little updates.

The other day I loaded the truck up and did a 30min drive, then used a digital heat gun on the U-joint caps (mid 90s out here). U-joint caps are all within about 110-130 degrees.

Carrier bearing and slip joint area were around 200 degrees which seemed a little hot. Its new and greased.

Did a runout test on driveshaft (rearmost section), about .03" in middle and .05-.06" towards the slip joint, using calipers mounted on a jackstand.

The driveline shop said could be the drive shaft/joints causing the shake or something else. They are a week out, so when I can have the truck sitting for a week may pull it and see if they say its unbalanced/bent/etc.

In the meantime have considered borrowing/buying a go pro and mounting it in various spots under the truck to see if I can pinpoint the shake.

I'll update, thanks