Saw a B&M transmission temp kit for a TH350 which has a sensor which T’s into the cooler return line. Not sure if this is best thing to do, so I’ll ask here. Also, is there a port that I can add a sensor into the case? I’d rather not drill/tap into my pan unless I have to.

 

The cooler return line seems like the worst place to put a temp sensor - you'll be measuring the temp out of the cooler, not the temp in the trans. I would think that if you had to use one of the cooler lines, the line TO the cooler would be a better choice.

 

If your fluid is a nice bright red color, then your temps are fine and would rather throw money at things that matter. If your not drag racing or towing I doubt you have any reason to monitor it.

 

Exactly. It isn't going to change much once the trans is up to temp, and when the novelty wears off in a week you'll stop looking at it.

 

Thanks to you both for advising. I’m upgrading the torque converter and was told that it could cause excess heat and to keep an eye on it. It’s not a crazy stall (2500) and it’s currently routed to the radiator for cooling.

 

Higher stall speed will definitely increase trans temp due to the slippage. Spend the money on an aux cooler rather than a gauge.

 

I know zip about that. Is that something I would mount by my radiator and AC condenser? Then run new lines from that to the trans and cap the ports on the radiator currently being used?

 

The factory aux trans cooler actually was plumbed in series with the radiator cooler. And since this always brings up the "before or after" question, I'll point out that the factory put the aux cooler AFTER the radiator cooler. I suspect this is because the liquid-to-liquid cooler in the radiator is more efficient than the liquid-to-air aux cooler.

 

Thank you Joe. I’ll take a look at some aftermarket ones. Any recommendations of ones to look at or avoid?

 

Hayden is a pretty well respected brand. I've also used the coolers from Earl's Supply. The reality is that we're just talking about an aluminum tube and fins.

 

Your torque converter is not going to create a lot of heat unless you are putting a heavy load on it.

 

More slippage creates more heat. Whether that converter is enough to matter is a reasonable question, but it will be slipping the whole time you're driving. This is one of those better safe than sorry situations for me.

 

I have a Hughes Performance 2500 RPM stall converter on my car and it has very little slippage while cruising (~300 RPM), very similar to the factory converter. I also live in a place where the summer temps are over 100F for 5 months on average, and I have not had a need for an additional aftermarket trans cooler.

 

I have a Coan 10 inch converter in my car, it flashes to about 4000 when you stand on it. It drives very well, it’s not mushy on the street. In other words, a well built quality converter.

I have a Autometer trans temp gauge, the hottest I have ever seen the trans temp go is about 200. That was in 90* heat, pulling a small U Hual trailer on a 2 lane winding state highway during Drag Week. About the worst possible conditions. I’m using a Be-Cool radiator, factory deep pan, and that’s it. No auxiliary cooler.

if your rowing, or really beating on the car, then a temp gauge in the pan is ok. The converter your using is pretty mild, just a couple hundred RPM over stock. Save your money on the gauge, put it towards a small cooler.