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My '85 L Series touring wagon has a knocking noise coming from the front and I don't know what it is. This knocking can be felt through the floor of the car.
When I accelerate up to speed it's not there but when I'm coasting along pressing the accelerator to maintain speed it's really bad. It goes away when I a) take my foot off the accelerator and b) when veering around a bend to the left but is there while driving straight and veering to the right.
It happens at all speeds up to about 80-90kph. At this speed it is a faster but quieter sound and I can't feel it through the floor BUT last night, while decelerating from 100kph it momentarily felt as if I was driving along a slightly corrugated, dirt road...
If anyone has any ideas about the possible cause of this knocking I would be very grateful!

Best to drop into one of those suspension places and get them to do one of them 100 point checks and give you a quote to fix.. then post what they said on here and we'll let you know what you need to get done.

As there could be lots of things under your car that can make noises and trying to diagnose it without hearing it or seeing it.. we'll you could be spending heaps

Seems like a wheel bearing to me.
I just picked up a blue l series with a similar problem but at the rear and it was the rear wheel bearing.

Front uni joint going into gearbox maybe. Had similar noise myself and found it to be front uni. Even though your travelling in two wheel drive and the tailshaft is not engaged it will still turn at some speed due to energy forces involved.

Since they are getting in their age, it would be wearing out and the joints & bushes could be on its way out, my liberty's control arm was making knocking noises on bumps - the bush was worn out - could be something like that.
Cheers
AP

If you have car jack and safety stands to securely support car, I'd get under with a good torch and check everthing nut bolt and look of things generally to see if it enlightens you to the problem. Gearbox mount? engine mount? CV joint?

There are a lot of things it could be, ie:CV joint, wheel bearing, loose wheel nuts, loose Hub nut, worn radius rod rubbers, radius rod mount detaching from subframe,loose lift kit if you have one, worn uni joint in the steering knuckle, broken engine or gearbox mount, wheel out of balance with a worn tie rod or a worn ball joint perhaps, as they are front wheel drive any of these problems generally will be transmitted through the floor or steering wheel at some stage.
Cheers
Grant

Thanks for your advice. It sure sounds like it could be one of many different things so I will take it to a suspension place and get their opinion and a quote. Does anyone know of a good place to take it to in Perth?

check your wheel nuts. I had these noises happen once. I thought that it was something more costly but i had 3 out of 4 wheel nuts loose.

Well, before taking her to get looked at I decided to take your advice and check that all the nuts were tight. The wheel nuts were fine but the left hub nut was loose. I tightened it up and took her for a short spin and so far no knocking noise so hopefully that's the end of it. So, I just want to know why the hub nut came loose...would it happen because of a shot wheel bearing or do they sometimes just come loose? I've been suspecting a wheel bearing problem for a while so if that's an obvious sign I'll go ahead and get a bearing kit tomorrow.

It probably just wasn't tightened properly to start with, your cone washer might need replacing now though as driving around with a loose hub nut doesn't do them much good.
Cheers
Grant