Mystery wobble / vibration

[spruce m00se]

Hi guys,

I was looking for some help.

I have had some vibration for some time which seems to come and go. But when its there it seems to resonate through the vehicle.

I have had 4 new tyres fitted and balanced / traced today, that has removed a lot of the vibration, but it is always there and seems to get worse after about 15 mins of highway driving.

I have a slight rear diff whine at 80 - 90 kmh under load, which was there when i got the vehicle I just didnt notice it.

Along with the vibration, which was greatly reduced with tyres, I have a rumbling under deceleration.

Both the rumble and vibration are the same under load and coasting. The vibration seems to get worse at around 100 kmh.

I have only found this post:
http://www.explorerforum.com/forums/showthread.php?t=363202
which describes my problem quite well, but i would think that a loose bolt would be an unlikely cause.

Does anyone have any ideas?

 

[Number4]

Never seen someone with a U-Joint issue, so I'd be inclined to say that you have a hub bearing going bad.

 

[spruce m00se]

Well, the current plan is to have a look at each wheel / suspension points at a time and retorque whatever I can whilst checking the bearings,

I had a good look under it while it had the wheels off in the garage and nothing was visibly knackered. Except the boots around the top ball joints at the front, which dissapeared

 

[Number4]

Ball joint boots are common. When the bearings go bad, usually the only sign is noise and or vibration. Unless they have been bad for some time, they won't typically have play.

 

[gtyates]

Does it feel like it is coming form the rear? Do you feel like you are driving on a very wet or even icy road? If so, probably rear wheel bearings. My wife's '04 did this. See thread: http://www.explorerforum.com/forums/showthread.php?t=392243

Greg

 

[spruce m00se]

Sometimes it feels like the rear is moving, sometimes it shakes the seats, sometimes resonates through the whole car.

its getting worse though, so I guess whatever it is will raise its ugly head soon.

there is a knocking upfront when going over bumps, or offroad. The steering is tight and free of play though. So I hope that is just the ball joints on the upper control arms as they seem easy to change,

I did a rear diff oil change today, there has been diff whine from 80kmh to 100kmh once its hot, the old oil smelt kind of like a roasted chicken, had some metal particulate in it, (very very fine) but the gears all looked fine, there was no visable wear at all.

I filled it back up with about 2qts of 75w140. it seemed like more came out, when I removed the fill plug oil came out of it. maybe half a quart.

Im going to do the front diff this week. I dont fancy cracking the seal on it and usint RTV to seal it back up again, so I will suck all the oil I can out with an oil pump, and then refill. hopefully that will be better than nothing.

Then when my filler adator arrives I will have a go at the gearbox oil, again I dont fancy cracking the seal.......

 

[Number4]

[MENTION=280847]spruce m00se[/MENTION], if the seat shaking is from bad u-joints, you'll want to get that fixed soon. If they continue to degrade, they can damage the rear diff as well as the transmission.

The knocking going over speed bumps is probably your sway bar. If the links are original, then replace them, along with the frame bushings.
I thought my less-than-one-year-old Monroes had gone bad in the front. As my sway bar links were OE, I thought I'd replace them before going through the hassle of front shocks again. Turns out it was sway bar.

 

[leadfootdriver]

My U Joints were dried out. If I were you, I'd get the vehicle on jack stands, and shake each wheel to check for play. I'd do the same on the Driveshaft. Taking off the driveshaft is easy, but you'll need a 12point-12mm socket and some thread locker to put it back together.

Lol, the nasty smell is friction modifier. The TSB is to do an 8oz overfill. That translates to just adding 2 quarts thru the ABS sensor hole after draining; real easy to do.

 

[spruce m00se]

Well, while it was up in the air having the oil changed a couple of weeks ago I had a look around.
the rear right drive shaft has about 0.5 - 1 cm or sideways play in it. I guess that will be what is causing the vibration, all the others are solid.

I came to the conclusion that the anti roll bar on the front end might be causing the knocks, and so i tightened the drop links. It all got better for about 2 weeks, now it is the same as it was again, I have purchased some new drop links (moog) and some bushings and will change them shortly.

I may do the front end upper control arms at the same time.

Unfortunately I coudlnt check the wheels for bearing play as they put it up on the alignment ramps. I will have to jack it up and have a go at finding some play later, maybe when they are rotating the tyres next month.

 

[spruce m00se]

So, an update to this,
I have taken it to a garage three times and they havent found any problems while test driving it.

I changed the drop links on the sway bar, it seemed to get better for a few days then returned to normal.
I have checked each wheel for any bearing play, there is none at all at 12 and 6 oclock, when i try 3 and 9 it is really easy to move the whole steering rack.

I have put a pry bar on the top ball joints and there is no play when the wheel is on the road or jacked up.

I just noticed that the CV joint coming from the transfer case to the frint drive shaft was totalled. It had a good half inch of play in it when pushing up and down and left and right. So I got one of those and changed it. I also regreased the two of the caps on the front CV of the same shaft, I couldnt get the other two caps off. But the needle bearings inside looked fine, and there was no marking on the surface of the cross thingy of the cv joint. I put it all back together and went for a drive.

The first drive was perfect, no shaking all the way to 140kmh.

The next day I noticed a small noise that sounded like a driveshaft or bearing, and though that this was now audible as most of the noise had now gone after changing the CV joint on the driveshaft.

Today, 300km later, the vibration in the front end came back, shaking at 110kmh. Shaking the steering wheel and sounding like a bad bearing or driveshaft.

I think the easiest thing to do is set it on fire!!

Any sugegstions on what to do next?
I noticed that there was about 10 degree of movement in the front diff input before the wheels started to move.
I also noticed, a very very slight sticking feeling sometimes when turning the front right wheel by hand which I didnt notice when doing the front right.
This was before I saw the CV joint was bad at the TC though.

Also I noticed that two of the bushings that mount the front DIFF are Knackered.
And the body mount bushings that joint the body to the chassis are crumbling.