Truck info: 1998 RAM 1500, 5.2l V8, 215k rebuilt transmission couple thousand miles ago.

Ok i have a loud clunk when going into reverse i know thats probably normal but, I had put the truck in park tired spinning the drive shaft, wouldn't move. Put it in neutral and i could twist the drive shaft like an inch, put in back into park and could now still move it about a inch. Are the u-joints shot? From what i'm hearing the driveshaft isn't supposed to move at all.

Also i don't really get any shaking while driving but i do hear a moaning sound going at about 25mph with my foot light on the gas.

 

When you were in park the first time, you may have had the weight of the truck keeping the driveshaft tight, depending on how you parked. When checking for play, you'll want to chock the tires on flat ground, and put it in neutral. This is what i'm assuming you did the second time you checked.

Play could be caused by a few things. When in neutral and with the tires chocked as stated above, grab the driveshaft near each u-joint and give it a few good jerks with some or all of your weight in each direction to see if there's any play. Now, grab as close to the rear axle as you can, and jerk it too. The flange coming out of the rear pumpkin should not have any play in any direction.

Most likely, it's your pinion preload. This is a common problem with the Chrysler 9.25 axle.

It's called the 9.25 Clunk.

 

I tried yanking it by the rear and saw that flange going into the rear diff move in and out a little. I'm not sure if this clunk is because of the u joints or the pinion and ring, sometimes I let off the gas before it shifts and I get a clunk as well

 

The clunk you describe is fairly normal. The movement in the pinion is not. Need to address that before it gets really expensive.

Or, ignore it for a while, and when it goes, use it as an excuse to re-gear both ends with something better....... (don't tell your wife/parents I said that though..... )

 

Haha. No I'm only 17 years old and new to this. I'm just tired of hearing this clunk everytime I shift into reverse. I'm hoping it's u joints cause pinion and ring could get expensive

 

It will get more expensive if not corrected.

 

Also get a noticeable "jolt" going from neutral to reverse and reverse to drive or neutral to drive

 

Set up a video camera pointed at the flange coming out of the rear end and replicate the clunk in different fashions (neutral to reverse, drive to reverse, etc).

Watch the video that was recorded and see how much the flange moves each time it is shifted. You can also aim it at each u-joint and do the same. The play will be very obvious on the video.

Sorta like this:
http://www.youtube.com/watch?v=LEHn8-9exnA

The 9.25's pinion preload design is about worthless. Basically, the pinion isn't able to hold it's preload setting which can make the pinion a little sloppy in and out.

You can re-set the pinion preload, but who knows if this will fix it on a worn axle. And if it did, it would probably just be temporary.

FYI- You can replace the crap crush sleeve with a solid pinion spacer. I believe they are made by a company called Ratech.

Most people just put up with the clunk until it becomes more than just an annoyance.