Terrible clunking sound

[chargd72]

I put the front driveshaft on my Powerwagon.  It has a np203 transfer case.  When I drive straight it doesn't make a sound but when I turn it makes a loud clunking noise.  I can't tell if it's in the transfer case or if it's just the u-joints in the front shaft.  Here's a clip.  What do you think?

http://www.youtube.com/watch?v=cTHtS6N_7aI&feature=youtu.be

[bakerhillpins]

My money is on the u-joints. But what do I know. 

Seriously, I have had several u-joints go bad on vehicles and it always manifests itself with crunching sounds when turning but not straight. I suppose if you ignore it long enough it will happen going straight too.

[chargd72]

That's the fix I'm hoping for.  There are 3 of them on the driveshaft but still will be the easiest and less expensive fix.

[Shaners74]

Driveshaft noise will not change regardless of turning or driving straight. Is it in 4 wheel on dry pavement while turning that the noise occurs? (can't watch the video right now) If so, it's the difference in the gear ratios between front & back while turning.

[chargd72]

Driveshaft noise will not change regardless of turning or driving straight. Is it in 4 wheel on dry pavement while turning that the noise occurs? (can't watch the video right now) If so, it's the difference in the gear ratios between front & back while turning.

Yes.  It was actually in 4 LOC when it was happening.  Is that typical?  Why would the gearing be different?

[Troy]

Driveshaft noise will not change regardless of turning or driving straight. Is it in 4 wheel on dry pavement while turning that the noise occurs? (can't watch the video right now) If so, it's the difference in the gear ratios between front & back while turning.

Yes.  It was actually in 4 LOC when it was happening.  Is that typical?  Why would the gearing be different?

That is pretty much normal - worse if you have large tires! Ideally the front and rear axles have the same gearing. However, as you turn, the outside front wheel has to travel farther. The tighter the turn the bigger the difference between sides. After a few feet of travel with the inside wheel barely moving it puts the gears into a bind. Stock axles have some "slip" but not that much and, eventually, it will "hop" or skid - but mainly it just makes a lot of noise. Try not to drive in 4WD on dry pavement and never drive in 4LO unless you're on soft/slick surface. When in 4WD it's best not to try to turn full lock. Whenever I'm in 4LO I make very shallow turns no matter what surface I'm on - except snow when I'm doing donuts!

I just watched the video. You probably felt the massive binding as you were turning since you had to give it a bunch of gas to complete the turn.

Troy

[chargd72]

Thanks, Troy.  That's good to hear.  I'm riding on 35s so that makes sense.  Now I just need to fix the shift lever so I can get it out of 4 LOC.

[twodko]

 Adding to the fray here.....if you have a TruTrack, Detriot or other type of locking differential in the front it will make
bad sounds and will hop like a low rider.

[bakerhillpins]

Yea, what they say... I just assumed you were in 2wd since you didn't state.   

[hatersaurusrex]

What Troy said is correct, in as far as driving on pavement in a traditional 4WD vehicle will cause binding, but it's not the front differential's fault.   What's really happening is - when you turn - the overall speed of both the front wheels (together) is a different rate than both the rear ones, which causes a bind somewhere along the drivetrain.   Without a system to compensate for the binding between the front and rear drivetrains, then you get either wheel hop, skidding, or clunking.  This is the main difference between full-time 4WD/AWD vehicles and traditional part-time 4WD vehicles.   A full time system will typically have a viscous coupling or a slip clutch of some sort to prevent the binding.   When you're in dirt, gravel, or mud, the wheels can slip more and this isn't an issue (normally)

Not to split hairs, but it's important to understand what's causing what when diagnosing problems.  Not driving on pavement in 4WD will likely cure your problem - in fact your truck may be just functioning normally and not need any repairs.   If you get clunking when testing in loose soil/dirt (and the noise is still coming from the front) the culprit is likely u-joints.   Also - if the axle is an open knuckle type, the problem could be the u-joint that sits out at the end of the shaft next to the knuckle, not the ones on the drive shaft.

Good luck!

[stripedelete]

Driveshaft noise will not change regardless of turning or driving straight. Is it in 4 wheel on dry pavement while turning that the noise occurs? (can't watch the video right now) If so, it's the difference in the gear ratios between front & back while turning.

Yes.  It was actually in 4 LOC when it was happening.  Is that typical?  Why would the gearing be different?

except snow when I'm doing donuts!

Power Wagons are the Best Donuts Ever!  You spin on a axis right under your butt. 

[Tilar]

I don't know if Dodge used them, but if it has a New Process transfer case you have a snap ring busted inside the transfer case where the final drive comes out of the transfer case. Easy fix. Remove the drive shaft and the cover on the transfer case (4 bolts). when you pop that cover off you will see the old snap ring and where the new one goes.

[chargd72]

Alright guys. Now I'm really confused. I finally free up the shifter and get it into 4WD Hi. Put it in gear and hear a buzzing sound. So I pop open the transfer case and the chain is loose as hell. So the chain spinning around the sprocket was obviously the buzzing sound. But why does 4WD Hi Loc still work if the chain is so loose? I don't understand how the np203 works.

[Tilar]

 Because 4wd high is not driven by the chain. It's direct from the transmission. The chain only drives the front differential.

[chargd72]

Because 4wd high is not driven by the chain. It's direct from the transmission. The chain only drives the front differential.

Do you mean 4wd hi Loc is not driven by the chain? Because that's the only way the truck will move

[Tilar]

What I meant to say is 2wd is not driven by the chain. Sorry I should have had another cup of coffee that early before posting.   

2wd high should still move. The chain only runs the front differential. Low range is run through a set of planetary gears which could also make noise.

[GreenMachine]

His truck is full time 4WD

[chargd72]

What I meant to say is 2wd is not driven by the chain. Sorry I should have had another cup of coffee that early before posting.   

2wd high should still move. The chain only runs the front differential. Low range is run through a set of planetary gears which could also make noise.

Yeah, you're thinking of the np205.  I have an np203 so it only has Low LOC-Low-Neutral-Hi-Hi LOC.  That's what's confusing me.  If the chain really is the problem then it must not drive Hi LOC.

[chargd72]

Here is a quick video of how bad the chain play is.  If someone could give me some insight on what they think needs to be fixed that would be great.

http://www.youtube.com/watch?v=DhkCB4z5dYI&feature=youtu.be