"I'm pickin' up good vibrations..."

[DiscoMatt]

I have a 200 Tdi Discovery with a nasty wobble. There is some vibration noticeable at virtually all speeds, but I originally thought this was just down to the 'tractor engine' up front. Now, when I get up to between 55-65, it is so severe that the steering wheel tries jump out of my hands and wobbles fast and violently about 1-2 inches. Bit scary. I keep expecting Scotty to shout "..she cannie take any more cap'n..she's breaking up.."

The bearings are fine. Thought it might be the swivel pin pre-load, but did that and it made no difference to the wobble, though it did tighten up the steering nicely. Seen some earlier posts about UJs causing vibration, but frankly wouldn't know a good one from a duffer...how can you tell? Could a duff UJ cause so much vibration?

Any advice gratefully received.

:dunno1:

[Spanners Akimbo]

Hi, Check the Panhard rod bushes, these went on a old rangie I had and It gave the same sort of symptons. It may be just loose bolts but the bushes do tend to wear quite badly and when this happens the whole front axle starts to move around.
Also It's possible that you may have lost a few balancing weights off the wheels, putting the wheel balance out. This has happened to my disco a few times as garages tend to use those stick on weights for alloy wheels but they tend to fall off a lot especially if you use it off road. The wheels being out of balance can make a suprisingly big difference so it's well worth checking.

Greg.

[DiscoMatt]

Thanks for the tip about the panhard rod bushes, Greg. I have taken a quick look at it and it seems to be rock solid. Would you expect some sort of play if the bushes were shot? Or do you think that there might be nothing discernable from the outside and you only get to find out when you take it apart? Loathed to do a job that might not be necessary, but as it is the only open line of inquiry, I'll probably give it a try next weekend.

I have had the balancing checked already by Quickfit and, although they said there were out and charged me to correct them, it made no difference. As an aside, when I went back 2 weeks later to have my tracking checked, I told them it had made no difference and they did the tracking for free (a £24 job for the price of a £10 wheel balance!). This was especilaly good news because the tracking took him 40 minutes because the adjuster bar was jammed (aren't they always) and he hurt his shoulder freeing it. Better his shoulder than mine, especially when its free. :yay:

[Spanners Akimbo]

I don't think that it's very easy to tell if the bushes are worn just by looking and pulling on the panhard rod, as then have quite a lot of weight on them normally. You could try jacking the front of the motor up and then have a go at levering them with a big screwdriver. I replaced the ones in my old rangie with a some polybush ones which I bought individually from John Craddock for about a tenner. Once you've got the old rubber ones out refitting the polybushes is easy, so It's not a bad a job as you may think.
I thought of something else to check which may also give the same problems. Is the steering box and steering box drop arm on tightly? These are pigs to remove when you need to but I've known them to come loose on some motors in the past. While your in that area also check the ball joint in the drop arm as these wear quite badly. On the older type rangie steering boxes there is a adjuster on the top to take out the backlash but i'm not sure wether or not the disco ones still have that, if they do it might be worth having a look at that as well. Also while you underneath have a good look at your steering damper, If these fail they can make the steering very erratic.
I'm fairly sure that your problem lies somewhere in the front axle steering location, rather than propshafts. In my experience if a prop is out of balance or a UJ has failed then it usually make a horrible noise, but only on overrun an although there may well be a constant vibration it's more of a speed related buzz than the full on death wobble that you seem to get.
It could possibly be a knackered CV or diff in the front axle but I would expect it to be making a right racket if this was the case.
Happy Hunting!!
Greg.

Ps When I first bought my disco it had a fairly bad wobble on it at speed. This was caused by the fact that one of the front tyres had gone flat while it had been standing and althought it'd been pumped up and looked OK, the weight of the motor had damaged the tyre in some way causing the vibration. I found this out by swapping the suspect wheel and tyre with the spare. So it might also be worth trying this especially as it's free!! ( mind you if you've had them balanced I'd expect that they'd of picked that up)

[DiscoMatt]

Thanks for all the tips Greg. Certainly seems like I'll have a fun weekend with the spanners. Ordered some new bushes and bolts for the panhard rod (whole lot for £5, rubber bushes), so I hope they arrive by the weekend. I'll take a look at all your others suggestions, too. I'll let you know if I find anything.

Matt

[DiscoMatt]

Did the Panhard Rod bushes yesterday. What a faff getting the old bushes out!! You don't mind that it takes so long doing a job for the first time, because you can usually conclude with the thought that now you know how its done, the next time will be quicker. Not so yesterday! After having to resort to extreme violence and totally destroying the old bush to get them out, I'm not sure it'll be any easier next time.:p

The workshop manual was very instructive: using a vice and piece of pipe, remove the old bush. You wouldn't believe how many pieces of bent pipe lie on my garage floor this morning :buck:

There must be a trick of the trade for getting old bushes out? Any thoughts?

PS. The death wobble seems to have retired after the last tightening of the swivel-pins (it always was intermittent, so not totally convinced yet). Not sure whether the panhard rod bushes made a difference. There is still a lot of vibration, which makes my wife ill! All the steering linkages look firmly in place. I think eliminating this vibration is going to be a long job...