Speedo Sensor Replacement - More help please...
Discussion
Hi,
As I am going to have the car up on Axle Stands to change the Exhaust Manifolds I am also going to tackle replacing the Speedo Sensor.
I had the Speedo out recently when I replaced the dash and as the needle would never go above 90 MPH I sent it off for a service at ETB, when everything was back together no difference, so I guess the next step is the sensor!?
Rather than just remove, clean reset the gap I am going to fit a new sensor.
Anyone had any experience of doing this?
Kind regards
Steve
Poole, Dorset
As I am going to have the car up on Axle Stands to change the Exhaust Manifolds I am also going to tackle replacing the Speedo Sensor.
I had the Speedo out recently when I replaced the dash and as the needle would never go above 90 MPH I sent it off for a service at ETB, when everything was back together no difference, so I guess the next step is the sensor!?
Rather than just remove, clean reset the gap I am going to fit a new sensor.
Anyone had any experience of doing this?
Kind regards
Steve
Poole, Dorset
Yes, it's a complete pain to get to and setting the gap is a nightmare. You have to remove the exhaust to get to it at all but even then it's difficult.
I think some of them have an integral toothed wheel but mine seems to be a bit of sheet steel cut into a circle and then the teeth formed by cutting them out and bending them over held in place by sandwiching it between the diff flange and the propshat flange.
Don't know if it's the same on all Griffs but the toothed wheel that's used on mine seemed to be very susceptible to being knocked and bending the tabs which meant setting the gap to the micro millimetre gap was impossible
I used the Steve Heath sensor which will work with a much bigger gap and found that to be much easier.
Colin
I think some of them have an integral toothed wheel but mine seems to be a bit of sheet steel cut into a circle and then the teeth formed by cutting them out and bending them over held in place by sandwiching it between the diff flange and the propshat flange.
Don't know if it's the same on all Griffs but the toothed wheel that's used on mine seemed to be very susceptible to being knocked and bending the tabs which meant setting the gap to the micro millimetre gap was impossible
I used the Steve Heath sensor which will work with a much bigger gap and found that to be much easier.
Colin
Done it on mine. A pig to remove from the drive shaft. 26mm Lock nut impossible to remove. Undo the whole bracket to remove. 3, 13mm bolts. Lock nut had to be drilled and split with chisel in vice. Plug and socket also a pig since it is just above the exhaust and subject to heat and dirt. Exhaust does not need to be removed. You need small hands and a good light. Gap I think is 11/12 thou, check. Can be done with patience. Now fixed, glad it was not the expensive speedo £250. Got new sensor from Clev Trev.
It largely depends on what diff you have & the year of car. You are going to end up with folks talking about completely different things if you're not more specific.
I'd hazard a guess if you have ETB dials, then it is the GKN diff with crown wheel on the diff/propshaft flange. IF you also have the T5 box I'd be looking at the stupid black box that splits the signal to the ECU (Lt77 boxes have a separate gearbox drive to the ECU).
I'd hazard a guess if you have ETB dials, then it is the GKN diff with crown wheel on the diff/propshaft flange. IF you also have the T5 box I'd be looking at the stupid black box that splits the signal to the ECU (Lt77 boxes have a separate gearbox drive to the ECU).
make shore i think green and black wire that is signal wire to speedo from sensor will take 12v disconnect both ends and test with multy meter or 12 v head light bulb ie put 12v in 1 end and bulb connected to earth the other end if there is a bad wire or connection bulb will be dim or won't work had this before where had continuity but under pulse would die out at speed ! if not is sensor gap is 12 tho make shore teeth on pick up wheel r all in line and dont touch sensor hope this help
Edited by jeremyc on Tuesday 13th December 09:42
Get the Steve Heath upgraded replacement.. It's easy to install and doesn't need such a tight gap. It comes with a diagnostics box to test operation and an led inside the sensor to check the gap is ok. It also has better resolution so it will tell you your speed below 5mph which the orignal won't. Good upgrade!
Hi,
I bought Steve Heath’s sensor but it was compatible with my ETB Speedo, real same as I am a real fan of his kit and upgrades, in fact this is the only one I don’t own, and that is only because it won’t fit…
So... old sensor off after removing the driver’s side rear wheel.
Not quite as difficult as I thought it was going to be but I am glad I have got long arms...
Before fitting the new senor I have a couple of questions:
Does the sensor work by picking up the tab or the gap on the cage, the reason for the question is that my tabs are covered in rust, road dirt & what looks like under-seal so I guess it would work better if cleaned right back to the metal and a very thin coat of rust proving paint applied!?
(Thinking about it I guess the cleaner it is, the closer the senor can get to the cage meaning I can get the gap much closer...)
Looking at the photo below it does look like I have an issue with some of the tabs as I can see a very faint line on ‘some’ of the tabs, so I guess that will need sorting refitting the sensor!?
Leading to question 2: What should the sensor to cage gap be, is 11/12 thou as stated above correct!?
As always thank you in advance for any help and advice.
Regards
Steve
Poole, Dorset
I bought Steve Heath’s sensor but it was compatible with my ETB Speedo, real same as I am a real fan of his kit and upgrades, in fact this is the only one I don’t own, and that is only because it won’t fit…
So... old sensor off after removing the driver’s side rear wheel.
Not quite as difficult as I thought it was going to be but I am glad I have got long arms...
Before fitting the new senor I have a couple of questions:
Does the sensor work by picking up the tab or the gap on the cage, the reason for the question is that my tabs are covered in rust, road dirt & what looks like under-seal so I guess it would work better if cleaned right back to the metal and a very thin coat of rust proving paint applied!?
(Thinking about it I guess the cleaner it is, the closer the senor can get to the cage meaning I can get the gap much closer...)
Looking at the photo below it does look like I have an issue with some of the tabs as I can see a very faint line on ‘some’ of the tabs, so I guess that will need sorting refitting the sensor!?
Leading to question 2: What should the sensor to cage gap be, is 11/12 thou as stated above correct!?
As always thank you in advance for any help and advice.
Regards
Steve
Poole, Dorset
Your wheel will be fine, the magnetic properties are'nt affected by it being nce & shiney 
Looks like there is a trace on the crown ~ has someone closed the gap like they need to set it on the drive shaft type trigger wheels? The large well separated teeth mean you don't have to get the sensor so close - mine runs happily at around a gap of about 3mm / 1/8" set by eye.
Looks like there is a trace on the crown ~ has someone closed the gap like they need to set it on the drive shaft type trigger wheels? The large well separated teeth mean you don't have to get the sensor so close - mine runs happily at around a gap of about 3mm / 1/8" set by eye.
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