What secures the speedo sensor ring to the driveshaft ?

[Somchai]

As the title says, is it just an interference fit or does it have a fixing that I can't see ? My speedo stopped working and it appears that the sensor ring has moved in (away from the diff) and is in danger of hitting the nuts on the carrier. It's no longer in line with the end of hall effect sensor in it's bracket. Any info would be appreciated.

[Jonathan Kay]

Private Message sent.

[Somchai]

[simon_h]

Should be an interference fit. Probably heated and then slid on when the joint is made. Have heard of them coming loose before. 

Might be able to push it back into place and with some decent loctite get it to stay put 

[Somchai]

Thanks. I had hoped it was "shrunk" on. Will heat it and tap it clear of the nut head and back in line with the sensor. Plenty of info on the sensor/bracket but couldn't find anything on the ring. Pics online/assembly guide show it much closer to the rubber gaiter side of the driveshaft than mine. 

[Somchai]

[aerobod - near CYYC]

If there is any rust on the driveshaft mounting surface, there is a risk the ring has a crack in it due to being forced open by the rust (a common problem on many Ford vehicles over here in North America). Check the ring carefully for a crack with a magnifying glass as it may only be a fraction of a mm wide, if there is one.

[Somchai]

Thanks James. Good tip, I will check, a crack may explain how it shifted. Just lucky it hasn't impacted the nut 

[John Vine]

The ring is fitted hot and allowed to cool.  For your sake, I hope it hasn't cracked as replacements seem almost impossible to find. 

JV
 

[ScottR400D]

Given that CC don’t supply some fairly basic driveshaft components as spares I’d be doubtful that they’d ever supply the speedo sensor ring on its own. 

That looks to me like you’re headed towards a new £300+ driveshaft. 

[John Vine]

... I’d be doubtful that they’d ever supply the speedo sensor ring on its own. 

That's my experience, too.  There's a recent thread on this subject from Tuck2020.  He was looking for a reluctor ring (amongst other things), so it might be worthwhile asking him if he had any success.  One suggestion was to try to find a scrap shaft (with ring). 

During that discussion, I asked Darren in Parts whether he could supply the ring, and if not, could he suggest an alternative source (such as CC's driveshaft supplier).  This was his reply:

"Not an easy one this as keeping the ring in place is a nightmare, we have had one come loose and never managed to put it back in place where it would stay put. So, looks like a shaft I am afraid." 

 

JV

[ScottR400D]

I can imagine that once the ring comes loose it wouldn't be possible to put it back in place. There must be some reason why it moved in the first place.

As has been said corrosion is an issue, preventing corrosion undermining the ring from new should help but once it's happened it'll be impossible to get a good fit.

When I had my diff out earlier in the year I gave both shafts a thorough examination and painted the exposed parts of the CVJ housings. It seems odd that that that isn't done from new, to me.

[Somchai]

Well hoping to get the car up in the air tomorrow and see if there is any movement in the ring. Really need to check how eccentric it is. Looks kinda cocked but no sign of impact. Hoping I can heat it and tap it back square. As for securing it against further movement. I've been considering options from a large hose clamp/jubilee clip tightened alongside, some loctite cylindrical retaining compound or even a generous bead of sikaflex... Hmmmmmmm

[Wrightpayne]

These guys maybe worth a try - I've looked at them for 911 reluctor rings.

https://reluctorrings.com/cars/ford

[aerobod - near CYYC]

Wow! They are very expensive on that site. I paid CAD$11 / £6 for a Ford Escape 44 tooth one last year, which is a similar spec to others on that site for around £40.

I believe the Caterham one is bespoke, though. Neither Rover or Ford, it has a larger difference between inner and outer diameters than generally used by mainline manufacturers.

[John Vine]

I believe the Caterham one is bespoke, though.

That certainly figures, given CC's reluctance to divulge details of their driveshaft supplier.  Does anyone know who the supplier is?

JV

[Wrightpayne]

I don't know for sure but Bailey Morris would be my first call.

I do wonder if there is a production one that is close that can be modified providing it has the right number of teeth (or the speedo can be reprogrammed to suit a different number).

[ScottR400D]

I would think the speedo could be recalculated, it’s a matter of finding one with the exact same ID and close to same OD. 

B-M might be worth checking with but if they are CC’s supplier they’ve likely been tied into a supplying only CC contract like others. 

[EEK]

Could something like that not be 3D printed?

 

[John Vine]

Re #18:

I agree. 

Caerbont's Electronic Programmable Speedo can be reprogrammed easily to handle quite a variety of teeth numbers.

Re possible contract terms, I'd hope that a supplier would be free to at least say where the rings come from.  Given that CC don't sell them, perhaps they'd also be happy (permitted) to supply as well?

JV