Took my 2004 with 86k miles into the local LR dealer recently as they offered a free total inspection, and I have been feeling and hearing a slight humming or vibration from the chassis at idle. Dealer came up with a bad rear coupler ($468) and they attributed the vibration to that. However I suspect they rushed through the inspection and may have just said that (it was a guess anyways the service adviser said.)

Could the rear coupler be the cause of the vibration? Or maybe the front driveshaft is about to go (never have rebuilt the u-joint as recomended by you guys).

I also have a bad front pinion seal ($513), lightly leaking T-Case (common said they and only $775 to fix) and- big surprise- slightly leaking head gasket (only $3600).

Quick side note on the leaks: I just had all the fluids replaced, including the T-case, so should I just monitor the fluid level in it or should I solve the leak problem- or maybe I can just tighten some screws and bolts to fix the problem, or maybe add a little stop leak fluid?

Should I get on the bad rear coupler right away?

Last, I didn't grease the front drive shaft yet- will bearing grease spread around the movable parts be enough? I promise to rebuild it with serviceable u-joints soon.

 

You can get your driveshaft rebuilt for $200 bucks. The coupler can be a cause but you can safely eliminate the driveshaft as a cause for much cheaper first obviously.

I think just about every one on this forums t-case leaks. Most of run 85-140 gear oil with a bottle of white sheppard to stop or slow down leaks. Mine is leaking bad enough that I need to pull and reseal but I'm tired of working on my truck for the moment. You can try these options and see if they help a little bit.

I would pressure test the truck yourself to verify a weeping head gasket, it could very well be the valley pan or something else as well. Greasing the existing fittings will help but if your driveshaft is already nearing its end, then the u-joints will fail regardless of the grease you pump into them. It's anyone's guess on how long your DS will last. The signs are not always obvious. When I had mine rebuilt, the guy said my stock joints were still plenty good, but I wanted to go ahead and take care of it.

 

I think you could pull either shaft and drive it. If the vibration is gone when the front or rear is out, you found the cause for that specific issue. Just read one of the members' posts about chocking your wheels when doing removing the DS so you don get tire marks on your face...

Are you getting misfires and have codes related to the leaky HG? Or do you hear the waterfall sound under the dash from combustion gas being forced into the coolant?

 

Vibration or humming at idle is not a drive shaft.
As you are not moving.

The Discovery 2 seems to whine a bit at idle.
Partly the power steering pump being mounted metal to metal.

Or it is the transmission.

I changed the power steering pump.
I changed the transmission fluid and filter.
I am ignoring the hum or whine at idle now.

 

Oh, duh... idling being the KEY word I missed in Tsuami's post...

 

Funny! You're right- if sound happens at idle then not driveshafts- duh!
I just changed tranny fluid so I'm going to investigate the power steering pump. Do they normally go bad around this mileage? Can I possibly just tighten some bolts to cure the noise?

 

I replaced my PS. Did not cure the noise.
I replaced fluids. Did not change the noise.

I took off the serpentine belt.
That cured the noise.

Problem is - the Discovery II needs the serpentine belt to be connected to run
the power steering, water pump, alternator, fan.

As you will notice..
Discovery 1 - Power steering pump mounted via rubber shock mounts.

Discovery 2 - Power steering pump just mounted to bracket which is mounted to engine. No rubber to deaden the sound.

There WAS a reason the Discovery I designers mounted the power steering pump to rubber.

 

Now you know not to ever go to the dealer again.
First, parts for the rear rotoflex are about $65, at it in no way can cause a vibration at idle.
If you want some help with these issues, PM me your number and I'll call you back.

 

Has anyone made rubber washers or something to help deaden the sound from the Power steering pump?