Slight grind/clunk

[SomeNewGuy]

Only have had this M1009 for about 2 weeks now, Ive changed all the belts and blood and found nothing other than normal wear when going through with a magnet. I have bypassed the relay and replaced the torsional dampener as well.

Under normal load below 35-40 mph (guessing here, spedometer is pretty damn off) everything is fine. Above these speeds there is a short, 1 second or less, low grind or chunk when I release the pedal, or move to accelerate. Once under power this noise does not persist nor happen again even if I accelerate harder, or pull off a bit.

ONLY when I fully release from the pedal, or when I start to give power does this happen.

It feels like it is coming from the rear of the engine-ish, maybe? Damn thing is loud at those speeds and its such a low sound I cant really tell.

Is this a normal sound she makes? Or something I should start looking into, and if so any place you would reccomend I start?

 

[vanaisa]

Check u-joints on driveshafts.

 

[SomeNewGuy]

Check u-joints on driveshafts.

So I got down there and checked it out, first two pictures are the rear shaft and second two are to the front. The front has a bit of wiggle room, as denoted by the separation of the sharipe marker.

I also noticed the... boot?... sheath?... whatever was loose however I did not notice much contaminants within upon closer inspection.

Nothing else found, everything still has its 10+ years of filth packed onto it so parts contacting where/when they shouldnt is out of the question.

Other than this, everything felt firm and as it should be... should I pull the joints apart and inspect/repack the bearings? Its a PITA to do, but I'm more than happy to employ my wifes small fingers for the task hahaha

 

[cucvrus]

You should set the parking brake, block the wheels and place the transmission in neutral. I would remove the rear drive shaft and inspect the U joints up front and personal. Anytime you place the vehicle in park on the ground the joints are going to appear tight. Judging from the pictures it would be worth the effort to press in some new U joints. Do yourself a favor and the truck. Do not use a hammer and socket. Clean the trunnions of the yoke and drive shaft and press new U joints in. If the clunking is still present check all the mounts on the engine and the transmission. At this point all the spring and shackle bushings are wasted and worn out. Consider replacing them as time and money allows. You bought this old truck and it will be a lot of fun work till you get all the worn out, wasted parts replaced. But after you are done you ca drive on for years. If you are looking for a quiet comfortable ride you bought the wrong vehicle. You have a lot of work ahead of you. Have Fun and Be Safe. Good Luck.