Speedo drive wheel-which do i need?

[The AJP Griff]

Hi all.I need a speedo trigger wheel for my resto project and i'm told there are a few differnt types,so i suppose thats no. of teeth etc?I have a GKN diff and want to run pre-cat type gauges,so as i'm about to start searching for one,what do i need to look for please?Cheers,Mike

[spend]

Didn't the pre-cat gauges run off the LT77 drive?

You may need a black box to convert pulses from the GKN propshaft trigger to correct count to your Stewart Warner dials if using T5 box. I have an idea there is a speedo drive in some T5 boxes - dont know if its present in the TVR ones, or if the drive would be compatible anyway?

Dave

[AntonyJ]

What box are you going to use Mike, the T5?

[The AJP Griff]

Thanks for the replies chaps.I'll be using a T5 box,Ant,which now you mention it,Dave,i realise was never fitted with the Stewart Warner gauges-doh!
So then,what i need is a trigger wheel for the later gauges(were there differnt types?)and a black box to convert the signal from the pick up(already fitted).It would be good if the black box could be adjusted to suit different speedo's,as i also have the S6 dash to use at some point,and this uses the '96 era type gauge.Would it be easier to just use any type of trigger wheel,assuming they differ,and then just get the gauges calibrated to suit?
One last question if i may?Can someone tell me where to get the Stewart Warner ones cosmetically refurbed,as well as calibrated,please?Cheers,Mike

[spend]

I think Stewart Turner still do gauges for Boats, they might still do repairs/refurbs (bought out by US corp, were based south coast I believe)? if not you'll have to try Speedy or ETB IIRC.

Dave

[AntonyJ]

When my speedo failed,(SW) I sent it to speedy cables, it needed a new IC, but they couldnt source one.
£30 for the info thanks.

Took it to a local industrial electronic repairer and they got the chip and put it in for free!!!

There must be something standard as the early 500's had GKN diff with SW gauges, didnt they?

[The AJP Griff]

AntonyJ said:

There must be something standard as the early 500's had GKN diff with SW gauges, didnt they?

Thats my set up exactly,but as Dave pointed out,i dont have the Rover gearbox,which is where the sender was on these

[AntonyJ]

I thought some early griffs had a GKN diff with a speedo sender on.

Certainly the one Sportmotive had a the growl was like this.

[The AJP Griff]

AntonyJ said:

I thought some early griffs had a GKN diff with a speedo sender on.

Certainly the one Sportmotive had a the growl was like this.

thanks for the tip Antony,i'll give them a call tomorrow and ask them about it

[Bluebottle]

AntonyJ said:

I thought some early griffs had a GKN diff with a speedo sender on.

Certainly the one Sportmotive had a the growl was like this.

My first Griff did to. (very early preserp 500 with precat dials)

Edited by Bluebottle on Tuesday 13th November 08:42

[Hoover.]

We had major problems with the speedo when we fitted a T5 box to my Griff....

Firstly the precats speedo runs from the gearbox and not the diff like the 500's so a component was manfactured to take the wire that spends the info to the speedo...

Problem.... the speedo was far from accurate, it was all over the place, ie breaking 100mph +, overtaking everything on motorway at 60mph.

Mark Adams had a look at it with a view to putting an inline variable resistor so that a level of accuray could be ascertained.

However when some voltage checks were carried out the signal was no where near strong enough to drive the speedo. After much playing, pulling the car apart looking for damaged/ miss wired cables sent the speedo of to speedy cables to get it recalibrated.......

Weeks latter (so much to be said for the word speedy...) got speedo and fitted however still the same problem....

Again whole car apart again..... still could not find an issue.

Speedo went back to speedy cables, and had whole new electronic new fitted, and refurbed glass n bezzel..... down side is that it now works like 500's speedo, ie starts from where 9 would be on clock, rather then 12. All took a bit getting used too as the speedo/ rev counter clocks appear to be going in diff directions (I know their not but thats how it appears)

I know it does not directly help .......

Hoover

Edited by Hoover. on Tuesday 13th November 08:54

[spend]

Had a quick look for you Mike, and it seems the Americans have plenty of mechanical gears for the T5 gearbox take off. Maybe mating the Rover sensor to the correctly geared wheel on the T5 would be the easiest solution?

You might be able to use a cable driven ST gauge from the Wedges? Steve Heath might be worth talking to, but I suspect he didn't give 2 hoots about the gauges when his shed got t5'd.

Dave

[Hoover.]

Or you could rig something up to the hub/wheel..... I work with a kit car enthusiast who said that if they couldn't get speedo working from the gear box that it could be done from there using ABS sensors....

if you're interersted I could ask more

[The AJP Griff]

I think that for now i'll get the diff wheel and see what it does with the sensor thats on the car.Then i'll see if they can be calibrated to suit.Thanks again for all your help guys