TR2/3/3A TR3 Temperature Gauge

[Brooklands]

Is there a more reliable replacement for this that looks fairly authentic? When I re-attached my tachometer cable, I must have moved the capillary tube and it wrapped around the steering column and sheared while driving today. Thanks for any and all suggestions.

 

[angelfj1]

The gauge cluster in the TR-4 is identical to your 3B, but I believe the 4 and 4A used a temp sender and electrical gauge. Perhaps you can use this setup

Can someone confirm?

 

[Andrew Mace]

I believe that is correct. Currently on eBay is a temperature gauge mislabeled as TR2-3 when it is clearly an electrical gauge. FYI... (no financial interest....)

 

[Moseso]

Pretty sure this is true, but:

1) The electric gauge will have a flat lens. Just swap with your old curved lens for the proper look.

2) You'll need to find a gauge voltage regulator. The electric gauges have a separate voltage regulator. They read way high without it.

 

[Adrio]

that is exactly what I did. You need to find a very early TR4 temp guage and it will be almost (but not exactly) the same as the mechanical TR3 guage. The only differences are:
1) the flat glass (which you can change easily)
2) the temperature numbers printed on the face are slightly different. My car is in storage so I can't verify what the numbers are but if memory is good (and it never is for me) the TR4 numbers are 5 or 10 degrees different then the TR3 numbers.

Also the wire to the sender looks different then the capilary tube but I have seen on the internet a company that sells some 'camoflage' to make the wire and sender look like a capilary and bulb.

If you want to see a picture of the electric but looks authentic version I can get you that on the weekend.

 

[Brooklands]

I would appreciate the photos of the items just so I am sure I am looking for the right pieces. Thanks.

I know that my other choice is repairing the capillary tube connection. It broke right by the sensor on the radiator. Any alternative suggestions for that?

 

[martx-5]

I know that my other choice is repairing the capillary tube connection. It broke right by the sensor on the radiator. Any alternative suggestions for that?

You can repair the gauge yourself if you have some soldering and general mechanical skills. I did using the info in this link. Or, you can send the gauge up to Nisonger. They will repair the gauge for about $120, and it will come back looking brand new.

As long as you can keep the ether inside the gauge, they really are very reliable.

 

[TR3driver]

You need to find a very early TR4 temp guage and it will be almost (but not exactly) the same as the mechanical TR3 guage. The only differences are:
1) the flat glass (which you can change easily)

The first 10,000 or so TR4s had curved glass like the TR3. And at least the one I have has exactly the same numbers as the TR3, 90-180-230. If memory serves, the later 'flat glass' gauges also had a shroud over the needle pivot, so they look a little different even if you change the glass.

But IMO they aren't as accurate as the mechanical gauges, and I really dislike the slow response time, so I opted for a 270 degree sweep aftermarket mechanical gauge instead.

Yeah, it doesn't exactly match the other gauges, but I value function over form anyway.

 

[TexasKnucklehead]

I have an early TR4 gauge (with curved glass), a sending unit, and VR. Someday they'll actually be in the car. I doubt anyone will be able to tell them from original TR3 parts. I think it's funny that some complain about the lack of acuracy, while others use a stick to see how much gas is in the tank. Diversity is great.

 

[NutmegCT]

Dave - I've attached a graphic showing the routing of the capillary tube from sensor to firewall in a TR3A. Don't know if your B has the same engine.

Not sure how yours got twisted (?) around the steering column, but when I got my TR back in February, the tube was completely free to bounce around. It ran from the sensor outwards to the inner wing, then along the wing (not held down by anything) and finally to an opening in the firewall; after the firewall it had several 180 twists and bends before it met the gauge itself. Not pretty. Now I've got it almost all back to spec.

Let us know how it's going.

Tom

 

[Brooklands]

I probably will go ahead with sending this out to Nisonger for repair, but they want the sensor included in the package. I have attached a photo of mine. The end to the left is where it broke off just outside the photo. The wire coming out of the right connects into a box to control the electric fan. How does this unit detach from the radiator?

 

[Andrew Mace]

Hard to say how that would come off, since it's not exactly a "stock" installation! /bcforum/images/%%GRAEMLIN_URL%%/confused.gif

 

[TR3driver]

I'm confused ... if you are sending the temperature gauge to Nisonger's; why would they care about the sensor for the fan control ?

Anyway, my guess would be that you cut the plastic band around the rubber cushion. Then of course replace it with a new one when reinstalling. But that's just a WAG.

 

[Brooklands]

This is from the email I received when I contacted Nisonger's about the repairs:
"I would recommend sending the gauge along with the sensor since we sometimes find that several styles of sensors are used on the same make/model cars; this way we are sure to match the original. All of our rebuilds are calibrated to original factory specifications and are guaranteed for one year."

 

[NutmegCT]

Dave - the sensor they're talking about is the "plug" at the end of the capillary tube. One end of the tube is the gauge, the other end is the sensor.

I *think* that's what you're talking about?

Tom

 

[NutmegCT]

Here's an earlier thread that refers to removing a "stuck" sensor (bulb) from that thermostat housing:

https://www.britishcarforum.com/bcforum/u...true#Post323890

T.

 

[Geo Hahn]

Hard to say how that would come off, since it's not exactly a "stock" installation! /bcforum/images/%%GRAEMLIN_URL%%/confused.gif

If it is helpful, here is a picture of a more or less correct stock installation:

I couldn't tell much from your photo... the sensor threads into the thermostat housing and the buld is (guessing here) about an 1" long.

 

[Brooklands]

Tom,
And I think that attached to this sensor on the radiator. I am sorry that I had not photographed it earlier before the day it broke. It looks like there should be something that slides into this unit from the capillary tube. Could someone post a photo of what the radiator end of the tube looks like? Then I can see if that is also on the car somewhere, or if it is missing. Thanks.

 

[Brooklands]

George. Thanks, that should help.

 

[NutmegCT]

Dave - could you maybe post a picture of the entire left side of your engine? Something that shows the thermostat housing, the capillary tube, and back to the firewall? I'm still trying to figure out how turning your steering wheel column could bind up the capillary tube and break it.

Thanks.
Tom