545 trans temp gauge (help)

[Rogue1bus]

I’m trying to add a temp gauge to my 545 transmission (amtran pusher).

I’m having trouble figuring what parts I need. I did some searching but still couldn’t track down the info. I’m going to put the sending unit into the oil pan opposite the dipstick (same thread pitch).

I’m hopping someone can help me identify:

-What thread pitch/adaptor do I need to install the sending unit in the pan.
-Recommendation on a gauge would be great, especially with wires that can reach the rear of the bus, or designed to have normal wires spliced in between the sending unit and gauge. (Amazon if possible)

Thanks!

Exterior Painting is almost done!

[solleks]

I added one a few weeks ago in the pan as well. I think it was an 1/8 NPT tap that most gauge senders require. It will definately say in the instructions. I ordered mine off of summitracing.com they have a huge selection.

[Iceni John]

The temperature sender for my transmission temperature gauge is near the top of the TC housing, next to the fluid hose going to the remote cooler and the heat exchanger. It's there because the fluid is hottest there - it will be a few degrees cooler in the pan. See if there's a 1/2" port in your TC housing: I'm not familiar with AT transmissions.

Having an accurate temperature gauge for a non-locking transmission is critically important, but ideally it should also be paired with a good remote cooler to reduce the heatload into the engine's coolant. I use a Thermal Dynamics DB-00341DC cooler - it has a 14" fan, and it has 1" ports in and out. It works well.

John

[Rogue1bus]

Originally Posted by Iceni John

The temperature sender for my transmission temperature gauge is near the top of the TC housing, next to the fluid hose going to the remote cooler and the heat exchanger. It's there because the fluid is hottest there - it will be a few degrees cooler in the pan. See if there's a 1/2" port in your TC housing: I'm not familiar with AT transmissions.

Having an accurate temperature gauge for a non-locking transmission is critically important, but ideally it should also be paired with a good remote cooler to reduce the heatload into the engine's coolant. I use a Thermal Dynamics DB-00341DC cooler - it has a 14" fan, and it has 1" ports in and out. It works well.

John

How did you choose a cooler? IE how do you know what size you need etc?

Thanks

[Mr4btTahoe]

Most trans temp senders are 1/8npt.


If you want it in the pan, either buy a pan with a port.. or drop your pan.. drill the hole and weld in a 1/8npt pipe union.


I use a Longs Trucool 40k cooler on my shorty... might not be enough for a full size bus though. It's a massive cooler and keeps my trans at 125F most of the time.

[Iceni John]

Originally Posted by Rogue1bus

How did you choose a cooler? IE how do you know what size you need etc?

Thanks

Easy! That one is the only cooler that A) has 1" ports (anything smaller than that won't work for a big transmission like mine), and B) it's the largest size that would fit the only space I had available. With a decent 14" fan it moves a lot of air through it, and also through the hydraulic/PS fluid cooler next to it. The fan is switched on by a 195-degree temperature switch, or it can be switched on permanently in hot weather. Well worth it.

John

[cadillackid]

the 545 deep pan uses a large port sender.. i got mine right from navistar, i'll have to see if I can find a part number.. sometimes the wires are already run and you'll find a 2 pin weather-pak connector dummied out. which would be the port for that sender.



I dont know which gauge cluster you have but if you have the one with standard square gauges, circuit board medics will sell you the gauge that you can insert into the panel. in the far left middle position. or you can install an aftermarket gauge and sender.. I think the threads on the 545 pan are 7/8 flare.. i dont remember them being NPT like some ive seen..

-Christopher

[Rogue1bus]

I Really appreciate the replies.

[brokedown]

I'm planning to add a temp sensor and extra cooler to the Wanderlounge, so I'm very interested in specifics people have used on their AT545s!

[Booyah45828]

Originally Posted by brokedown

I'm planning to add a temp sensor and extra cooler to the Wanderlounge, so I'm very interested in specifics people have used on their AT545s!

I used an autometer 140-300 oil temp gauge. It was an old gauge I had laying around, I'd guess it to be pn 5447. I purchased and used their #2258 sender which is 1/8 npt, and includes 3/8 and 1/2 adapters.

I put it in the cooler line leaving the transmission. It's the forward line on an at545. Originally it has an elbow coming out which uses an AN fitting connecting it to the steel hard line going to the cooler.

I took a T-fitting like this.



Female end went to the elbow on the trans. The male end opposite of it went to the steel line to the cooler (line was shortened and re-flared to 37°). The T in the connection was then tapped for the proper thread.

IIRC I used 1/4 npt in the tee fitting which then required me to use 1/4mpt - 1/8fpt adapter, which wasn't included with the sensor. Not a big deal though because the adapter is available at most hardware stores.

The whole deal went pretty easily and works as it should. But I have a shop full of tools so YMMV.