I'm getting some vibration between about 60-80kph. It doesn't go away when I let off the gas. The tires were rotated and balanced, but that doesn't seem to have solved it.

Anyone have ideas on what the potential causes are for this, and how should I go about diagnosing? I replaced the front driveshaft a few months ago, so I'm thinking it's not likely to be that. It has just been in the shop, where they replaced a worn rear diff, but the problem existed before this job.

I'm thinking about messing with the shafts, although as I understand it, the vibration should change depending on acceleration if it's a shaft issue. It seemed more likely to be a wheel issue given that it varies based on speed, but this is just my amateurish assessment.

 

Do you have aftermarket wheels or newer LR3/Range Rover wheels on your D2?

Sometimes the cheap plastic hub centric spacers get thrashed and throw the wheels off.

 

I have the original wheels, and I don't believe there are any spacers (correct me if I'm wrong). I just got the car back and am going to go under and check things out when it cools down.

 

The spacer I was talking about is on the hub, you are good.

I would jack it up(wheels off the ground) and start looking for play.

 

I jacked it up and tested for wheel play. The wheels are absolutely solid. The body rocks on the suspension, but the wheels themselves have no play.

Because it was easy to do, I also took the grease nipple off the front shaft to see if it'd change the vibration at all (technically you're not supposed to leave the nipple on there). No difference there.

I'm thinking now about next steps. I don't have a CDL (I have a weird non-US-spec '04 with no locking diff), so I can't remove the front shaft and drive around.

FWIW the vibration feels like it's coming from the front of the vehicle. It starts as a lurch-y slow vibration at 60kph and then gets more rocky at 80kph.

 

Possibly a balance weight fallen off the drive shaft? I would imagine there would be a sharp tack of weld remaining, which might be possible to find.

I once had a vibration on a car that was impossible to track down. Turned out to be one of the wheels had smacked a curb, which had very slightly physically bent the rim. Only spotted it by spinning the wheel and looking for movement on the metal at the far outside. Was only moving maybe 3-4mm out of true. (Not the tyre)

 

Check out your track bar and... I can't remember the name of the other. Anyway, your tie rods. Mine were getting kinda rough and I had the same problem. Same for ball joints. Its also possible for a wheel bearing to be bad but not be able to nice play with it jacked up. I've got one like that right now. That said, they usually make some awful squeaking and grinding.

 

Had a vibration caused by a nail in a tire let water in while wheeling. Then when back on road, the nail got pushed in even further and sealed the hole. Couldnt find it for months until i got new tires and found one was full of water.

Another vibration i notice is the correlation between fuel level. Anything above 1/4 tank, truck drives smooth. Under 1/4 tanks, vibration at speed.

 

I've inspected the driveshaft, and I don't think any balancing weights have fallen off. I don't see any evidence of broken welds. Nonetheless, I decided to slap a hose clamp on the shaft (this effectively puts a weight wherever the screw is) and drive it around. I don't think there was any difference, though there could've been something subtle. I'm going to try putting on another clamp tomorrow to experiment and see if the balance changes the vibration. So far I'm not optimistic that the driveshaft is the culprit, especially given that it's only a few months old and I've been driving on it with no trouble until now.

I don't think it's ball joints, as I had those replaced earlier this year. I also am not noticing any play in the steering rods at the front. They feel very solid.

I'd normally be suspicious of the tires/wheels, but they've been balanced and rotated with no change in the vibration. If there were a flaw in the wheels, I'd think that would have been corrected/caught in balancing.

I took a cursory look at the engine mounts and didn't see anything abnormal. Hmm....not sure what to test next.

 

Might be the output flange on the front of the t-case. Mine was loose and it caused vibration. If is that all you have to do is remove the frond driver shaft and tighten up the the 30mm bolt that holds the flange on.