Dual Gauge Disassembly Tips

Dual Gauge Disassembly Tips

Author
Discussion

ukkid35

Original Poster:

6,256 posts

176 months

Thursday 23rd May
quotequote all
The coolant temp gauge can ratchet up when the coolant overheats, so that it over reads from that point on, this time by 90deg

It's happened to me with an old dual gauge, and it's just happened again with the one I have currently

Any tips on disassembly so that can try to reset it?

plasticman

901 posts

254 months

Tuesday 28th May
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I have done it a couple of times and it is pretty simple apart from the process of removing the bezel slowly working round the back edge a bit at a time.

DuncanM

6,261 posts

282 months

Tuesday 28th May
quotequote all
plasticman said:
I have done it a couple of times and it is pretty simple apart from the process of removing the bezel slowly working round the back edge a bit at a time.
This, there is no such thing is too carefully for this bit, mine looks ok, but in retrospect, I would have used a more delicate method/tool, as the alloy bezel is a bit scratched.

ukkid35

Original Poster:

6,256 posts

176 months

Wednesday 26th June
quotequote all
I've asked Caerbont if they can supply new bezels, I suspect they will decline

I've managed to find a supplier of black bezels (rather than brushed aluminium) that might work, but there's a long delivery delay

DuncanM

6,261 posts

282 months

Wednesday 26th June
quotequote all
ukkid35 said:
I've asked Caerbont if they can supply new bezels, I suspect they will decline

I've managed to find a supplier of black bezels (rather than brushed aluminium) that might work, but there's a long delivery delay
Have you destroyed your bezel?

ukkid35

Original Poster:

6,256 posts

176 months

Wednesday 26th June
quotequote all
DuncanM said:
Have you destroyed your bezel?
Not yet but it's on the cards

DuncanM

6,261 posts

282 months

Wednesday 26th June
quotequote all
ukkid35 said:
Not yet but it's on the cards
biggrin

I back you to get the job done, I was clumsy at first, mine are still fine.

ukkid35

Original Poster:

6,256 posts

176 months

Wednesday 26th June
quotequote all
All I need to do is flick the needle back round to its cold resting place



At least I've managed to fit the oil temp gauge at last, I fitted the sender a couple of years ago



Even so that was definitely a non-trivial job

DuncanM

6,261 posts

282 months

Thursday 27th June
quotequote all
ukkid35 said:
All I need to do is flick the needle back round to its cold resting place



At least I've managed to fit the oil temp gauge at last, I fitted the sender a couple of years ago



Even so that was definitely a non-trivial job
The bezel will prise off, and you'll be able to reuse it by pushing the lip back on. Regarding the needle, you may need to use something sticky to keep it on in the right place, I regret not using something stickier, and may end up in the same situation as you.

Please note, that despite my needle resting in the correct place, it still over reads a little compared to the ecu. Correct calibration would need you to run the ecu diags, and get the needle to read the same, as the spring still has tension in the resting place.

Hope that makes sense!

ukkid35

Original Poster:

6,256 posts

176 months

Thursday 27th June
quotequote all
Thanks, very useful to know

Do you prize off the outside lip, or the inside lip?

notaping

299 posts

74 months

Thursday 27th June
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This is the best vid I've seen on this . .

https://www.youtube.com/watch?v=8OAVZ1POuG8&t=...

but there are loads on the Tube.

DuncanM

6,261 posts

282 months

Thursday 27th June
quotequote all
ukkid35 said:
Thanks, very useful to know

Do you prize off the outside lip, or the inside lip?
Outside, around the back of the dial case, that's why it's doable without causing any viewable damage.

Honestly think you'll find it easy enough, although I did have mine on a table, not attached to the car. I'd want to use something sticky but not brittle (superglue) to hold the need in place, when calibrating.

Mine is only out by 10°, and consistent when comparing to ecu, so I'm leaving it for now.

ukkid35

Original Poster:

6,256 posts

176 months

Thursday 27th June
quotequote all
Thanks for the video

I will be taking it out completely to do this, but there is no gap between the bezel and the case, so getting a pointy tool in cleanly will be tricky

Also, I'm very conscious of the chance of damaging the capillary, which would be very annoying

DuncanM

6,261 posts

282 months

Thursday 27th June
quotequote all


Bottom right corner, you can see the bezel, with the back opened up.

Byker28i

62,689 posts

220 months

ukkid35

Original Poster:

6,256 posts

176 months

Thursday 27th June
quotequote all
Anyone had one repaired by the ironically named SpeedyCables recently, if so how much?

They charged me a very reasonable £45 ++ but that was 12 years ago

jeremyc

23,963 posts

287 months

Thursday 27th June
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It might be worth contacting The Gauge Shop

I haven't used them myself, but they come recommended in Caterham circles.

DuncanM

6,261 posts

282 months

Thursday 27th June
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Byker28i said:
BHA4900 is the same gauge, just need to swap face and bezel.

I bought new for under £100 a few years back.

https://www.bmcparts.co.uk/products/mgb-dual-oil-w...

To add link, good price.

notaping

299 posts

74 months

Thursday 27th June
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Smiths Telemetrix are the gauges - without TVR branding.

https://www.merlinmotorsport.co.uk/s/instruments-g...

Still need to swap face and needles, BUT the bezel's the same.


FarmyardPants

4,134 posts

221 months

Thursday 27th June
quotequote all
I think my temp gauge is reasonably accurate - in cool weather it sits at 82c which is the stat temp