Heavy clunk from rear end when starting

From a complete stop, usually after being parked for several hours/ over night, When I first attempt to move the vehicle forward, there is a audible, almost loud, thunk that occurs. Only one thunk/clunk/thud, but you can actually feel it come up through the truck.

A recent example was parked on slight incline in driveway, I went to coast down and realized the truck didn't want to roll, as if the parking brake was on. I had to put it in gear and let the clutch out to force it to move. Because I was parked on an incline, I did have the parking brake on, but took it off before I noticed the truck wasn't budging.

Other info:
I usually park on flat ground so I don't always have the parking brake on, but the thunk, grabbing hesitation at the initial start of movement has happened at those times as well.

I thought it might be parking brake related, but since it doesn't always happen then, maybe that isn't the problem?

It doesn't happen every time.

Could the drum brakes be the culprit? They don't make any other tell tale signs of bad brakes like grinding noise when in use or while rolling.

90000 miles on truck.

U-joints are tight.

Diff fluid always comes out relatively clean and with not metal shavings.






Any thoughts would be appreciated.

 

There was another post on this a while back, but what you're describing sounds pretty normal. If I recall correctly, it is something along the lines of a "brake check" that is performed anytime the truck is shut off after a certain length of time. Happens to me every day.

Nothing to worry about.

 

It's been happening on and off for quite a while. Nothing I'm too concerned with, but I've been dealing with other driveline and or brake issues for a while and I'm just trying to figure out whats causing what. I'm going to be driving across the country, living in and out of my truck for a while coming up and I just want to make sure its all in proper working order.

Thanks for the replies.

 

I had this problem too. Happened when pulling away from stop lights sometimes too. Turned out to be the slip yoke on the drive shaft. Because I have a warranty they replaced the entire driveshaft, but I know there is a tutorial on here on re greasing it.

 

My slip yoke does have some play in it. Not sure how much is acceptable. I'm ordering a one piece driveshaft today so that will be eliminated as an issue hopefully.