Speedo and a vibrating sound

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Mon, 09/03/2015 - 11:41
mish
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Hi

Our speedo  has suddenly become very jumpy at around 40 - 70 mph. When the engine is warm is seems to get a little better and more stable. Does anyone know what might cause this?

Also on a cold morning we get a vibrating sound rising and falling with accelaration coming for behind the dash again once engine is warmed up this goes away. The only thing I can see under the bonnet in that position is the break servo. The brakes are working fine.

Any help would be great.

Thanks 

Hamish 

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Mon, 09/03/2015 - 11:42
#1
mish
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Re: Speedo and a vibrating sound

Vibration / whining sound sorry 

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Mon, 09/03/2015 - 12:17
#2
Arnie
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Re: Speedo and a vibrating sound

It's most likely that the speedo cable is worn through its sleeve lining and is sticking, making the speedo needle jumpy and giving a whining noise.

You should start by fitting a new cable. However, the worm, drive-gear that connects the cable to the transfer case also wears, so best to change both these items.

The speedometer clocks themselves also eventually fail, as the internal gears and bearings wear, but start with the above first.

 

 

 

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Mon, 09/03/2015 - 13:49
#3
mish
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Re: Speedo and a vibrating sound

Hi Arnie 

 

thanks that would all make perfect reasoning as it get used a little more the sticking and nosie stops.

is it a massive job placing the cable? I am pretty sure I am going to have to have the dash and centre consol out to do the heater fan.

 

thanks 

Hamish 

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Mon, 09/03/2015 - 15:04
#4
Simon666
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Re: Speedo and a vibrating sound
Hi I notice yours is a 463... jumping/intermittent speeds are common on 460's like mine - another reason to be very careful of claimed milage.. As you've already been advise could be as simple as a loose fit into the speedo reverse. One thing other might be able to advise on though is ease of speedo cable replacement. On a 460 the guys who look after my G said they would rather wait until they have to drop the gearbox as the takeoff point is inaccessible unless you are doing this :-)) Hopefully they had a think by the time they got to the 463 - Good luck Simon
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Mon, 09/03/2015 - 18:18
#5
Arnie
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Re: Speedo and a vibrating sound

Its a fairly simple job to thread through the new cable. You only need to remove the instrument binnacle and the lower knee panel (and steering wheel to get to the binnacle)

You might even be able to attach the new cable assembly to the old one and use it to pull the new one through.

The connection point on the transfer case is readily accessible from underneath. No need to remove gearbox or anything like that.

I did one 463 many years ago, but don't recall the details. Check MB WIS, if you have access.

On the 460, its even easier.

 

 

 

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Mon, 09/03/2015 - 21:40
#6
Simon666
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Re: Speedo and a vibrating sound
Hi Arnie Glad they sorted it for the 463 then. Must be to do with being a manual box on my 460 then - you definitely can't get at the take off end of the cable - expect with the very tips of your fingers - and I didn't recollect an access panel on the floor pan when I last had it stripped out to dynamite it. As you say routing after that is straight forward enough as long as you go the right way - mine appears to be from the take off point back to the speedo. Ta SImon
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Mon, 09/03/2015 - 22:58
#7
Arnie
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Re: Speedo and a vibrating sound

Perhaps that was for a 460 , 300gd manual, which I understand are as you describe, but for the auto, the cable attachment point is quite accessible on the transfer case.

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