putting temp sender in trans sump plug

[Pandave]

can this be done in place of drilling a new hole and welding a nut? i just bought a fan for the trans cooler (am placing it behind bumper cross member) and i read that the best temp reading is in the sump and not the lines. suggestions??

[Easy Rollins 1]

Get a "Watchdog" mate,it just bolts to a sump bolt.You can get a model that triggers fans etc.


Cheap as chips and made here in Brissie...

http://enginewatchdog.com/tm4.html

[rastus2571]

Yes mate that is correct as it is reading the gearbox temp.
I have installed many coolers on diffs,boxes,etc over the years.

As I say on here and in the trade that the number 1 killer of autos is heat.

Why do you want to run a temp sensor out of the auto sump plug when it could be ripped off when you are off road?

Auto trans fluid boiling point ballpark normal fluids such as Dexron is
315 degrees c or 599 degrees f.

Now this may seem quite excessive to heat..315 degrees C. Wow that's a lot.

Now, take this lot into account.

Where is your stock auto trans coooler on the XJ (and it is a little pissy thing anyway) in front of the A/C condenser, the grille,( your driving lights and bullbar and winch if you have them) and radiator.

So you can see now the amount of extra heat that poor little thing has to put up with and with any restriction in airflow it makes it all worse for both the tranny cooler and our poor radiator. Adding anything else to our vehicle makes that poor little sucker work harder.

My advice is to get a bigger cooler if you are really concerned about frying the box (as we all are and which I am doing) and mount it in the original position. You may have to play mount holes of course.

I have been looking at scalloping my grille fins out so I can run twin 10" thermos from the front to blow inwards.

Halfway got it sussed at the moment.

You don't have to do this just run a bigger cooler unit.

Many, many years ago I used to run a Class 7 off road racer as co-pilot FJ-40 with Ken O'Keefe who founded Ultimate Suspension in NSW.

I was Ken's first apprentice. This thing ran a worked 350 chev with believe it or not a tricked powerglide behind it.

It was a bullet.

Ken ran the auto cooler all the way down the back just above the rear axle and bolted it to the floor and stuck twin 10" thermos on it.

Now I am not telling you to do this.

Just get a bigger cooler and mount it in place of the original mate.

You can never have an auto run to cold.

You don't have to go the grille cut as I am thinking.

Run a bigger cooler and the stock system in good conditon wil handle it.

[Pandave]

hey easy rollins, sonds impresssive. shame the twin model doesn't come with fan relay, that would be optimal for me. one question though. you said to hook it up to the sump plug. how is that different than to put a sender there? wouldn't a sender and gauge be a bit cheaper?

[Billnick]

Originally Posted by Pandave

and i read that the best temp reading is in the sump and not the lines. suggestions??

I've got my sender in the lines, but it doesn't give you the overall temp of the reservoir. I took the easy option not the best.

[Easy Rollins 1]

Originally Posted by Pandave

hey easy rollins, sonds impresssive. shame the twin model doesn't come with fan relay, that would be optimal for me. one question though. you said to hook it up to the sump plug. how is that different than to put a sender there? wouldn't a sender and gauge be a bit cheaper?

I said to hook it up to a sump bolt...of which you have 19 to choose from.

[Pandave]

Originally Posted by Easy Rollins 1

I said to hook it up to a sump bolt...of which you have 19 to choose from.

my mistake.