Correct speed sensor diff clearance

[Blackbullet]

Morning All

Hopefully somebody can answer the above question. We've just had a new/refurbed diff fitted to our Griff, but now the speedo is completely inoperative. Dad found that the gap was more than 15mm which he thought was too far. Has reduced it to about 4-5mm but still no joy.

It doesn't mention it in the bible and forum searching seems to be out for me at the moment.

Many thanks
Andy

[Slacey]

I beleieve it needs to be as close as possible without actually fouling, ie. as small a distance as you can get.

[SHIFTY]

Informed by local TVR dealer that they set all TVR's at 1mm, also worth checking to see if there is a "v" groove cut out at the sensor end (on the thread), this has to be kept vertical to read correctly.

Edited by SHIFTY on Monday 24th March 10:45

[Blackbullet]

Thanks for the swift reply guys

Will check that out

regards
Andy

[chim666]

Slacey said:

I beleieve it needs to be as close as possible without actually fouling, ie. as small a distance as you can get.

[GreenV8S]

Blackbullet said:

the gap was more than 15mm

The gap needs to be around 0.5mm - 1.0mm. The bigger the gap the faster you will need to be going before the speedo picks up the signal.

[Spawn]

My speedo on the cerb only kick in at around 25mph. Would this be the same thing?

[VARLEYHYD]

Here we go

Speedo Sensor- Adjustment/Removal/replacement (sag v similar all T cars)


Part no. M1889 £100 ish Racing Green TVR



To gain access to the Speedo Sensor the car ideally needs to be on a ramp.(jack possibly)
Remove the left NS rear wheel.



The sensor can be seen at the right of the drive shaft, horizontal to the toothed diff output.





View from underneath the car.(exhausts removed on photo)

Clean with WD40 set to 1mm gap

The sensor is best left, complete on the bracket if removed.


View from rear (fuel tank removed)


If replacment required use a dealer as they will have it done in a jiffy

Alternativley, remove locknuts, follow the blue cable through to the rear inner wheel arch where it enters the body.



The hatch trim top rail and then the left NS trim panel needs to be removed.





Unplug in the inner wheel arch and prise out the wires and sheath from the connector block.

Pull the new sensor wire through, without cutting back the wire.

Remake the connector and re fit the sensor and bracket.
Alternatively cut off at 200mm long from plug then cut back new by 200mm and join with soldered heatshrink joint or sealed connector block.

Check with the ignition on the speedo needle reads zero.

If the needle requires adjustment, select factory settings on POD menu 8; select the mph zero and adjust up or down until the needle is set and save the changes.

Hope this helps

G

[LordGrover]

VARLEYHYD said:

Clear, concise instructions

Ridiculously pristine! It can't possibly have looked that good when it left the factory!

[crazymatelot]

VARLEYHYD said:

Here we go

Speedo Sensor- Adjustment/Removal/replacement (sag v similar all T cars)


Part no. M1889 £100 ish Racing Green TVR



To gain access to the Speedo Sensor the car ideally needs to be on a ramp.(jack possibly)
Remove the left NS rear wheel.



The sensor can be seen at the right of the drive shaft, horizontal to the toothed diff output.





View from underneath the car.(exhausts removed on photo)

Clean with WD40 set to 1mm gap

The sensor is best left, complete on the bracket if removed.


View from rear (fuel tank removed)


If replacment required use a dealer as they will have it done in a jiffy

Alternativley, remove locknuts, follow the blue cable through to the rear inner wheel arch where it enters the body.



The hatch trim top rail and then the left NS trim panel needs to be removed.





Unplug in the inner wheel arch and prise out the wires and sheath from the connector block.

Pull the new sensor wire through, without cutting back the wire.

Remake the connector and re fit the sensor and bracket.
Alternatively cut off at 200mm long from plug then cut back new by 200mm and join with soldered heatshrink joint or sealed connector block.

Check with the ignition on the speedo needle reads zero.

If the needle requires adjustment, select factory settings on POD menu 8; select the mph zero and adjust up or down until the needle is set and save the changes.

Hope this helps

G

£49.95 for the Cerb from Racetech Direct. Cerb has a much shorter cable, about 8 inches with a plug connector block which is connected very near to the diff.
edited to add: the gap as suggested should be as small as possible without touching. Use feeler gauges.

Edited by crazymatelot on Monday 24th March 23:17

[the man]

The early speedo sensor on a griff works between 6-8 thou. this should be a large thick sensor unless it has been modified to the later unit wich is about 68 thou.