4 wheel drive clunk

[treegump]

I decided to drive through my yard and so I shifted into 4 wheel drive on my truck. I have IFS and a manual shifter on the floor. I kept hearing a clunk when I was driving though. I can't remember if it was just a start and stop sound, but I don't think it was. Where should I start looking?

My boots are not punctured that I know of.
And it felt like it was working just fine.

 

[GMCYA]

Start with the U-joints

 

[treegump]

ok - thanks!

 

[GMCYA]

Look for rust around where the ujoint bearing seals are, most of the time it will look like a little rusty water is starting to seep out. A sure sign of a corroded bearing that pops when rotated.

 

[treegump]

Ok - so an update on this - I have IFS - so the only u-joints I can check are the driveshafts and the rear axle. I don't hear any noises coming from either of those places (besides a knock when I start in a gear - but I think something just needs tightened in the rear diff.).

I tried 4-wheeling a little bit yesterday - just trying to climb up a rather sharp incline and used 4-wheel drive. It made a clunking sound all the way up (never does it in 2 wheel drive)...and now in 2 wheel drive I've been noticing more and more each day that something is rattling in what sounds like the driver's side wheel-well. Oh, and none of the cv joints have tears in the coverings.

I guess my question is - is it possible for the joints to go bad even if there is no evidence of leakage, tearing in the cv joint? Also, would the rattling be audible if the joint were getting that bad?

 

[GMCYA]

I am assuming this noise is only in 4wd no matter the terrain?

If you really want to test your cv joints put it in 4wd on concrete or asphalt and turn the wheel hard left or/and to the right while driving slowly like trying to park . They make loud "clicking" "popping" noises when worn. Very unmistakable.

9/10 times if you have a bad u joint in the rear it will vibrate under acceleration.

If it only does it in 4wd is has to be either a cv or front u joint. Unless it is just slap azz wore out, it is almost impossible to to feel slack in the front u joints by hand due to the short drive shaft.

 

[treegump]

I am assuming this noise is only in 4wd no matter the terrain?

If you really want to test your cv joints put it in 4wd on concrete or asphalt and turn the wheel hard left or/and to the right while driving slowly like trying to park . They make loud "clicking" "popping" noises when worn. Very unmistakable.

9/10 times if you have a bad u joint in the rear it will vibrate under acceleration.

If it only does it in 4wd is has to be either a cv or front u joint. Unless it is just slap azz wore out, it is almost impossible to to feel slack in the front u joints by hand due to the short drive shaft.

It does only happen in 4wd and it doesn't matter what terrain. Since I have IFS - it'd be the cv joints. And to clarify - would the cv joint rattle or should I be checking something else? Everything on that corner has been replaced but the cv shaft - but I thought I'd jack it up when I got home and double check.

 

[GMCYA]

The only way it would rattle is if the bearings are completely out of the carrier which would mean that the cv is destroyed internally. They usually come apart at that point though. Jack it up and turn the wheel and see if you hear anything loose in the cv housing. The two I have changed before were exploded so to speak so no strange noise up to the failure point. The FWD cars will make clicking noises when turning when theirs go bad.

 

[treegump]

The only way it would rattle is if the bearings are completely out of the carrier which would mean that the cv is destroyed internally. They usually come apart at that point though. Jack it up and turn the wheel and see if you hear anything loose in the cv housing. The two I have changed before were exploded so to speak so no strange noise up to the failure point. The FWD cars will make clicking noises when turning when theirs go bad.

Jacked it up and turned the wheel and didn't hear anything. I called TurbineDoc as I was doing 70 down the interstate and he listed all the symptoms I was having and told me to check my motor mounts - doing that this evening. Is there any harm in removing my cv half-shaft and driving w/o it to see if the noise disappears? I don't want to buy the part if I don't need it but I've only got 1 vehicle.

 

[GMCYA]

You would be exposing the bearings to dirt and debris. A broken MM usually makes noise when you press and release the go pedal as the engine twist and resettles. It would do it in 2wd also. Check the bearings for slack also when you jack up the wheels off the ground. Have you tried to get someone to help listen from the outside on both sides to help pinpoint the source? Did you try locking it in and turning hard left/right driving slow in a small circle and listening for popping noises? Without actually hearing the sound it is almost impossible for me to point you exactly where to look.

 

[treegump]

i'm an idiot - the rattling that was getting worse and worse was my upper mount for my front shock.

I've still got the clunking in the front when the 4 wheel drive is engaged, though. And my steering feels lose - it likes to pull when it hits a bump - but when i tried removing my steering damper, it still had resistance. (and it was stuck so I just reinstalled it)

 

[hereismylife]

the pull it because it is on dry pavement. I do know what you are talking about. It kinda feels like you are in a fwd vehicle...

 

[treegump]

the pull it because it is on dry pavement. I do know what you are talking about. It kinda feels like you are in a fwd vehicle...

Sorry - i started on another tangent with that "pull". I was speaking more about when I'm in 2 wheel drive and hitting potholes or bumps on the interstate. But - I think the noise (in 4 wheel drive) is coming from either the front differential (there is a bit of play it seems), or the axle shaft or the wheel bearing on the passenger side. I've yet to investigate unfortunately.