routing of speedometer cable LHD 1986 4x4 petrol Syncro T25

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syncro4us
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routing of speedometer cable LHD 1986 4x4 petrol Syncro T25

Post by syncro4us »

Our speedometer has suffered from needle bounce at low speed say 0-15 kmph approx for some time (years) and nothing currently is solving this so have bought a new OEM cable 
from our usual reliable source.
Some years ago 2006 ish we replaced the radiator which sprung a leak in the Sierra Nevada in Spain so on checking the current routing I wondered if we had inadvertently routed it incorrectly before starting work to replace it with the new cable.
the current one goes as follows:-
1) goes from the back of the speedo to the fire wall and through the rubber grommet
2) goes round the front upright then around  behind the radiator and over the top of the fan motor at the rear of the radiator.
3)  from there it drops down the side to run along the RHS chassis  past the break pressure regulator then over the top to the cross member of the sub frame then into the side of the front diff box.

Can anyone confirm this routing of the cable is correct of have different information as to the correct route as I have looked in Haynes, Bentley etc and the web but can only find info for 2WD.
Kevin

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Re: routing of speedometer cable LHD 1986 4x4 petrol Syncro T25

Post by silverbullet »

That sounds absolutely correct. Through firewall, down the side of the steering column reinforcement, along the side of the chassis rail (inboard) then looping over to attach to diff.
Speedo cable might be dry, kinked, frayed all of which can cause the inner to whip or wind up and that makes the needle bounce)

2wd is a completely different arrangement, being driven from the nearside wheel direct via a drilling through the stub axle.
85 syncro Caravelle twin slider Oettinger T3200E-6
90 SA Microbus supercharged wbx/UN1 project

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syncro4us
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Re: routing of speedometer cable LHD 1986 4x4 petrol Syncro T25

Post by syncro4us »

so in our case the speedo cable goes around the steering colmn shroud then immediately behind the radiator above the fan in and S shape and crosses here so its close to the fan blades and only then drops down to the RHS to meet that chassis.

In your scenario do you mean
The cable  it drops down the LHS of the radiator to the chassis leg UNDER the Driver in our lhd then crosses over the top of the front diff to turn into the RHS of the box where the connector is?

So far I have also tried routing the new cable (leaving the old one in place for now as its difficult to get at behind the fan motor) from the RHS chassis across the water pipes near by the gear leaver selector box underneath then up the Left Hand side of the radiator this time well away from the fan motor and it looks like it leaves enough cable to hook up to the speedo with  much gentler curves?

any clarification would help
Kevin

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Re: routing of speedometer cable LHD 1986 4x4 petrol Syncro T25

Post by silverbullet »

I missed a critical bit of info at the start, sorry.
In my case, its a rhd, so the cable is much shorter anyway but the correct cable routing would still need to avoid the spare wheel (if fitted under the cab)
VW didnt do everything so well as to be faultless, they do have the odd failing and after 30+ years...?
I would remove the cable and spin it by hand to see if it has an obvious catch.
85 syncro Caravelle twin slider Oettinger T3200E-6
90 SA Microbus supercharged wbx/UN1 project

http://www.025motorsport.com

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syncro4us
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Re: routing of speedometer cable LHD 1986 4x4 petrol Syncro T25

Post by syncro4us »

I found a good route for the new cable and installed it after removing the old one which appeared to be a botch job as the outer bowden cable was joined half way along with some very strong shrink wrap.
The new cable is so smooth and no needle bounce at all.
Had a problem with the LPG Petrol switch which got knocked and all the timing was out but its ok now.

Any Idea what the vacuum? pipe is doing going to the rubber grommet on the top of the engine 2.1petrol that goes through the rubber to be near the flywheel on the other side.

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Re: routing of speedometer cable LHD 1986 4x4 petrol Syncro T25

Post by Aidan »

it's a breather to allow warm air from the clutch to balance so when you drive into a river the bellhousing doesn't suck in water and wash the clutch

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