Staghound Hydramatic Transmission Question

[Malcolm Towrie]

Well spotted on the pin, Rob. The pin is rigidly attached to a tang on the front band, so restricting its movement would prevent full band clamping, unless the pin is sized to buckle or something. You can see the pin and the tang in the right hand window of Marco's photos.

The Staghound engines had pressure and temp senders for engine oil and coolant installed but they hadn't been wired to the gauges on the instrument panel. I can see why. The senders were modern design which are totally incompatible with the old school radium-illuminated gauges on the panel. The original temp gauges need a 25 to 250 ohm variable resistance from the senders, but modern senders work more on the 2500 to 100 ohm range. Same with oil pressure. Modern senders don't work with 1940's gauges. So I gave up on the gauges and installed warning lights on the I/P, using modern switches set at 250F for coolant, and 5 psi for oil pressure.

I figure a bright red LED light will get more attention than a gauge going off-scale high or low anyway.
Malcolm

[rob love]

Stewart Warner still makes sending units in the ranges you need for the original gauges. I was just researching the subject tonight, as I need to replace/match up some of the gauges to their sending units. They have a very good webpage showing all of their gauges and sending units. That said, their prices can be intimidating if you are not careful about where you order from.

[Malcolm Towrie]

I checked out the Stewart Warner site but it seems the temp sender info doesnt give any degree-to-ohms calibration info (at least I couldn't find it), so they can't be matched to an original gauge, just a new SW gauge. Which is still a good option.
Also, none of the pressure senders, which do give psi-ohm calibrations, match the 0-30 ohm/0-60 psi calibration I found the original gauges have.

However, I did find this good information on all the NAPA Echlin senders and switches which allowed me to find a 5 psi low oil pressure, NC, 1/8"'NPT warning switch and a 250F high temp switch.

In hindsight, maybe I could have found senders for the original gauges with this list.

Malcolm

https://s3.amazonaws.com/pageturnpro...uide112011.pdf

[daninnm]

Hi!> I used a wire wound potentiometer to the gauge wire and turned the pot to get a full scale and then a low scale reading......reading the pot resistance at each point will give you the resistance range sender that the gauge wants to 'see' from the sender....
BTW::::: I have a ton of NOS Cadillac hydramatic parts including NOS clutch discs.
We are driving he Staghound and just moving onto finishing the radio and parts instalaltions in the turret and the upholstery in the turret basket.
DaninNM 5052692056

[Malcolm Towrie]

Dan, I did that for the pressure and temp gauges. I found the oil pressure gauges took 0-30 ohms to go from zero to full scale and the temp gauges took 25-250 ohms.
I have a database of all the senders that NAPA sells. Modern senders don't work anywhere close to these ranges. Have you managed to find senders that match these old gauges?


Malcolm