Transmission Temperature Gauge

Hi All. I have a 1985 Clipper 34 powered by a Lehman 120 and a Velvet drive gearbox (probably nothing new here). Both have associated heat exchangers of course.

For peace of mind I am thinking that a temperature gauge, perhaps with a built in alarm/light would be a good "upgrade".

Can anyone please advise me on where/how to do this (generally) or indeed if there is a better alternative?

I will have further details of the box and layout etc very soon if required but this may be enough to commence the discussion.
Thanks in advance
Ianmac

Which model BW? Ratio?

I also have the Borel Mfg alarm system. Love it and it was easy to install. But I don’t know if it will give a temp or is just an alarm.

There are 3 unused ports in the top of the transmission. You can install a temp sender for ~$70. You will then need to install an audible/visual alarm and mute for ~$30. It is factory set for 190F. EBay or https://bpi.ebasicpower.com

Borel makes a sensor for exhaust hose that will give you early warning of raw water pump failure. Probably a little faster than eng temp gauge.

Auto transmission temperature gauges are probably closer to the mark. There temperature senders, like this one from Summit Racing, for VDO gauges and others for different brand gauges. The trick is to find one that will fit the threaded fitting on the transmission and is the right length. I have done this for the transmission on a truck but had not thought about it for the transmissions on the boat.


Might be a good idea to check with Brian at American Diesel to see if they have one made to fit and also to find out where to install it.


Darn, now you have me thinking about it - guess I have to look into it.


Marty.........................


Edit - I looked in my Velvet Drive manuals and found this:
On Page 36 of the Service Manual I found reference to a Optional Drive Gear Alarm Kit, with two temperature switches, but no indication where the two switched would be installed.


In the Marine Installation Manual

Page 19 - Under Test Cooler Circuit -
The cooler size affects the oil temperature and lubrication pressures within the transmission; therefore, a test run should be made to insure that the transmission sump oil temperature falls between 14OoF (60~) and 19OoF (88~). The 19OoF maximum sump temperature should not be exceeded when running at full throttle for an extended period of time. Overheating can cause transmission failure.

Continuous monitoring of sump temperatures is possible when a thermocouple is installed in the cooler out circuit near the transmission. The thermocouple should always be placed in the oil circuit so the oil passes over the sending unit.

Page 23:
TRANSMISSION ALARM KIT A4867HN - This is the recommended method for monitoring transmission functions. The temperature will rise to indicate low oil level, low pressure or mechanical problems quicker than a pressure gauge will indicate a drop in line pressure.

TRANSMISSION ALARM KIT A4867HS - This kit is used in conjunction with the A4867HN kit. This kit provides extra components for making a dual station installation.

Thanks everyone for the replies - super quick too !

Not sure what sort of G/Box I have but the Pics may help someone to help me identify the box. I now just hope that I have been able to attach a couple of pics of my gearbox below:

Again thanks everyone so far.

ImacSS

Oops! I may have found something.



I went to the boat yesterday and took more photos and found what looks like a temp sender unit already fitted. Duh!



The photo below shows what I have - but didn't realise till now.


Thanks heaps everyone for your time to post all of that info which I will save as a future reference in the Boat file.

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Imacss said:

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Hi again,
From the Pics etc provided can anyone tell me what Gearbox that I have in my Clipper?
Thanks in advance
Ianmac

OKay, perhaps this time

AGAIN !! Apologies for my Luditte approach to posting photos.


Seems to be a flange with a connection of some sort, Havent tried to remove yet.
Ianmac

Assuming a mechanical gauge, I'm not understanding the utility of going to all the trouble of adding a gauge that must be physically looked at instead of just using an infrared temp device.

Imacss said:

AGAIN !! Apologies for my Luditte approach to posting photos.


Seems to be a flange with a connection of some sort, Havent tried to remove yet.
Ianmac

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Greetings,
Mr. I. "... a better alternative?" You have a couple of options IMO. Which one is better is your decision.


1). Leave everything as is and go for several trial runs where you can "shoot" the transmission temperatures (IR gun) under load. IF within spec's, forget about it other than keeping a close eye on condition and level of fluid. It may be a bother to do as I suspect your ER access is under the sole of the saloon via hatches. IR "guns" are quite inexpensive, now, and a reading every month, or so, may suffice. The ONE drawback is this will not alert you to any catastrophic failures.



2) Proceed with your initial thoughts and install gauge/alarm.


While quite nice to have, is it really necessary? How often does a transmission fail? NOT a rhetorical question. I simply never hear about it.

Imacss said:

AGAIN !! Apologies for my Luditte approach to posting photos.


Seems to be a flange with a connection of some sort, Havent tried to remove yet.
Ianmac

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I think that is your Neutral Safety Switch. Check out the Manual section of this forum. There is the Borg-Warner Velvet Drive installation manual there. I did not see the service manual so I just uploaded it. I presume it will show up once approved.


Marty.......................

Imacss said:

AGAIN !! Apologies for my Luditte approach to posting photos.

Click to expand...

It is a disconnected neutral safety switch on your CR2 transmission. Most disconnect it because any problem with the switch or wiring will leave you with an engine that won't start.

If you take it off you will need a gasket during reinstallation.

CR2 Box - ID now achieved : Thanks Guys!
Neutral Switch - Understand AND agree why it's disconnected - Thanks Guys!


As indicated my ER is a bit hard to get to in a hurry or indeed often.
I already have the IR Gun and have checked Gearbox temperature a few times but haven't noticed an elevated temperature so again understand - Thanks Guys!


Temptation is to just continue to monitor temp hoping that I don't get "bitten" etc one day but am inclined to err on the side of safety and explore the other options but at the moment I won't rush into it.


I read a lot of topics on this site and I note with interest how others are so willing to share their knowledge and experiences when a question is asked. The responses to my question are so typical and wonderful. Many thanks again for your replies.



I have now downloaded the Service Manual (bit late I realise) and even found a company in Brisbane (brother lives there) who has parts if ever I need them.


I'm sure one day a question will be asked that I may be able to offer an appropriate response.



Happy cruising everyone

This is a great site
Imacss

If you're looking for an easy-to-install temp gauge, check out Engine Watchdog. I suspect it may not be as accurate as a sensor that threads into the transmission, but it's at least as accurate as an IR thermometer without the hassle of crawling into the engine room.

I installed the Twin system to monitor our twin FL120s, and so far I'm pleased with the company and product. In fact, I ordered a second unit to install aboard our sailboat.

Maybe worth checking out: ENGINE WATCHDOG TM4, Engine Temperature Sensor and Low Coolant Alarm

Seems like a simple temp switch/alarm would be just as easy, though, and less expensive.