B&M trans temp gauge- what is your nominal temp?

Just curious, I installed mine but i thinks it [the gauge] is toast.

I have trouble shot the whole install:

The sender is "lightly" screwed in, i have tried it tight and not so tight.

The ring crimp is not in contact with the sender body. Only the terminal on it.

All the terminals are connected correctly.

I have the sender connected to the out line to the rad.

It has power and reads like this:


Get in Jeep and drive 12 miles 10 are highway.

Temp gauge reads 100, then near the end [9 miles] it will start to climb a little

Reads 130, then get off the highway and pull into drive through place,
reads 160.

Then i come home leave engine on and check connections and such, still reading 160.

I pull the gauge out while connected and running and it is super hot to the touch. If i had girly hads it would burn. As it was i could not hold the body long before i had to put it down.


So i think that the trans should read higher, sooner?

Also does not seem right for it to run so hot [the gauge].

Curious what your experience with this is, what your starting and "ending" temps are?

I just got mine hooked up and working about a month ago. When I first tried it out I was thinking it was not working as just driving around a few miles it would not move off the 100* mark. Then I took a long trip and it moved up to about 120* by the time I got home.

Once I started towing my trailer, then it really started to work. I put a larger tranny cooler in and bypassed the stock in radiator one but did put a thermostatic valve in that only routes fluid once it's warm enough. Normal freeway driving it runs about 160*-180*. If pulling a long hill or caught in stop and go traffic, it sees up to 210*. While offroading, especially in sand dunes, I have seen it as high as 250*.

Since I am not running this through the radiator anymore, I notice that my coolent temps don't climb as fast and hence, the electric fan does not kick in as soon. I think I am going to put a manual override switch so I can turn it on to help the tranny cooler a little more.

Another interesting note I saw, if I can keep the tranny converter in it's "locked up" state, it really helps keep the temps down. On my 2000, it will lock up in either 3rd or 4th gear depending on my selection. If I leave it on the overdrive setting on the selector but it keeps shifting in and out of overdrive (4th) it really brings the temps up quickly. I find if I run it in 3rd and it's not shifting back and forth, the temps come down. At 3000rpm's I'm doing 65mph which is 10 over in CA for towing a trailer so no problems. I also got 16.5-17.8mpg towing a 1500# trailer, so I was happy about that.

Hope that info helps.

Thanks for the informative post!

I am curious:

When you ran just the temp gauge with the stock cooling, what was the temp range? 100-120?

Also did you put the sender on the trans out or in line?

Finally, i too am going to install a hayden transmission cooler, actually have it set up already i just have not plumbed it yet as i wanted to get a baseline on my temps 1st without it.

My question is: you are now seeing temps higher when useing only the trans cooler and totally bypassing the rad? that is how you got the temps that you have now?

Yeah just trying to clarify..
thanks,

Aaron

I never used the external cooler or gauge setup with the stock radiator cooler inline. When I did this mod, I bypassed the stock one so I have no info regarding what it was like stock. I mainly did this because I knew I would be towing my offroad trailer across the Mojave Road and wanted to make sure things were cool enough.

As for the sender, based on the FSM and what I read on everywhere (the lower line on the radiator) it "should" have been on the line back into the tranny but after I installed it and then looked at which lines attached into the tranny, it was on the front line, which my understanding it the tranny output. Doh! I hate when manuals and real life are not the same.

In my case, I am seeing what the tranny output temps are, which will fluctuate more but gives a better idea of what the temps really are, at least that's my theory. LOL

aroncull said:

Thanks for the informative post!

I am curious:

When you ran just the temp gauge with the stock cooling, what was the temp range? 100-120?

Click to expand...

I'm bypassing the radiator running a stand-alone cooler and my temps aren't even that low... usually 160* once it's up to temp, and it takes a while to get there. "Stock", with the fluid going through the radiator and my factory Mopar trans cooler the temps were closer to 200*.

Thanks guys!

OK so how long do you think it takes for it to get up to temp?

I thought that since i live in colorado and it gets cold here that i would keep the stock cooling in line with the aftermarket cooler i have yet to plumb.

Again i get 160* only after driving and then stopping..

If my Rad temp gauge reads 210* i thought that the trans gauge would read there abouts as well. But the engine temp is taken from the Tstat and so... ok i get it now... thinking out loud, what do you guys think it should be at?

see you both have aftermarket coolers but im trying to get a guess at what the temp wouldbe with my set up...

im thinking 160*??

i know we are talking a guess, thanks!

I live in the short but steep Blue Ridge Mountains which are also known for the 3 "H's", Hot, Humid, and Hazy

On the road maybe 120 with no load on a 90+ high humidity summer day.

Towing a 3k# bass boat in the same conditions I might see 170

On the trail in the same conditions, around 170 as well.

My gauge has never been over 180 in 4 years.

My 30,000 GVWR Hayden cooler is plumbed to go back through the radiator after the cooler since it gets in the low teens here in the winter. I have 4 of my 5 XJ's with the exact same set-up.

On the install, did you run a ground to the sensor? I always run a ground from the nearest source and then strip about an inch or so of insulalation off of the wire and use a small worm clamp to hold it to the brass fitting away from the sender wire of course.

xjtrailrider said:

On the install, did you run a ground to the sensor? I always run a ground from the nearest source and then strip about an inch or so of insulalation off of the wire and use a small worm clamp to hold it to the brass fitting away from the sender wire of course.

Click to expand...

I was under the impression that the tubing was the ground, sounds like i should add an additional ground line to the sending unit, and clamp it to the body of the sender. [that is me restating your outline for clarity LOL]

Sound good?

Thank you

Aaron

aroncull said:

I was under the impression that the tubing was the ground, sounds like i should add an additional ground line to the sending unit, and clamp it to the body of the sender. [that is me restating your outline for clarity LOL]

Sound good?

Thank you

Aaron

Click to expand...

Right, the tubing is metal, but unless it is touching metal somewhere it probably is not grounded good enough. The tubing has "O" rings where it goes into the tranny and rubber hose at the radiator end. Chances are you need to add a chassis ground to it to make sure you are completing the circuit at the sender.

xjtrailrider said:

Right, the tubing is metal, but unless it is touching metal somewhere it probably is not grounded good enough. The tubing has "O" rings where it goes into the tranny and rubber hose at the radiator end. Chances are you need to add a chassis ground to it to make sure you are completing the circuit at the sender.

Click to expand...

Well said, i hadnt thought of that.

Thank you,

Aaron