BEST location for A/T heat sensor?

[Gary - K7GLD]

I'm figuring to order the deep pan for the 727 automatic transmission in my early '91 Dodge - and tho' it comes equipped for a temp sensor, wonder if the pan itself is the BEST point to be monitoring actual OPERATING temp rises in the transmission under load? Presumably, the oil in the PAN is the stuff that has mostly been thru the cooler, and MAY not give an accurate picture of extremes the fluid is being exposed to closer to the source of the heat-generating areas of the system?

Perhaps the line LEAVING the transmission, going to the external cooler would be prefferable?

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http://community. webshots.com/user/davison71 Early '91 250, 727 AT, 307 rear... Banks Stinger exhaust, intercooler... US Gear OD... Tweaked pump, upgraded radiator... MORE than a match for every new PS Ford encountered so far...

"Dura" WHAT? NOW I know where all those recycled beer cans go...

 

[illflem]

Gary, the output line to the cooler is the best place, your fluid can be overheated before it shows in the pan. I'm not sure how you go about it in a first gen, many second gen folks buy a output line for a '95 and install it, it has an outlet for a sender. Other folks have cut the output line and installed a compression tee for the sender, I don't like that idea because of potential leaks. Need a first generation guy to pipe in here.

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95' 25004X4,AT,Driftwood,Banks Stinger,Warn fender flairs and running boards(work truck)
95 3500,5 speed 3:54,BD E-brake,Driftwood,Banks&Psycotty,34,000 GCVW apple and tractor hauler(works harder truck)

 

[Wayne M.]

I take my temp at the pan lower side. The sender doubles as a drain plug. I follow the logic in putting the sender at the fluid out line (front line), but I assume that is the fluid that was just in the pan a second ago anyway. It just seemed easier and more reliable to braze in a fitting than to cut up those excellent factory lines.

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'92 W250,3. 54,auto,reg cab, raven hi top cap, tach,boost,transtemp,pyro. 16cm housing.

1971 Plymouth Duster 340 Autumn bronze, Black buckets/console. 8 pt roll cage, other racing mods. 12 second bracket racer. BOMBing not done yet!!

 

[Gary - K7GLD]

Another thought MIGHT be the latest gizmo from Geno's that fastens to the transmission dipstick - wonder if the same sensor could be secured to the output line from the transmission instead and carefully, thoroughly wrapped to maintain tight contact and heat insulation for proper accuracy in readings?

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http://community. webshots.com/user/davison71 Early '91 250, 727 AT, 307 rear... Banks Stinger exhaust, intercooler... US Gear OD... Tweaked pump, upgraded radiator... MORE than a match for every new PS Ford encountered so far...

"Dura" WHAT? NOW I know where all those recycled beer cans go...

[This message has been edited by Gary - KJ6Q (edited 04-18-2001). ]

 

[illflem]

Gary, I wanted to wait for a transmission service before I installed my trans temp gauge to avoid a mess, but had everything ready to go so I did what you speak of for a couple of months. I taped the sender to the output line and slipped some 1/2" pipe insulation over it. It's hard to be exact with the changing temperatures of the season, but it seemed to read about 20° low compared to when I finally installed it in the fluid flow. No big deal, but it also responded much slower, it would be better in the pan even though that isn't ideal.

 

[EMDDIESEL]

The most accurate readings will be from the transmission line going to the cooler. The pan is not an accrate place to get your temp reading from since the pan will shed heat quickly into the wind. As mentioned, you can fry your transmission and the gauge reading in the pan may not be that high. If you never tow or haul anything, The pan is fine. Otherwise mount the sender in the line to the engine mounted cooler. You dont have to braze anything. I called www.Jannettyracing.com and ordered the special Trans temp sender "block" and 2 compression fittings. You just cut the transmission line with a tubing cutter and mount the block in line using the compression fittings. Then screw the trans temp sender into the block. Takes about 35 minutes lying on the ground. You dont need a jack or lift. I put mine in 12k miles ago and it works great. The fittings and block if i rember correctly were about $40. 00. Give them a call and they will tell you esactly how to do it. They dont list it on there website, you have to call them. Get there number off there website.

 

[Ramboy00]

At Bill K's seminar south of Dallas, this was brought up and one of the members mentioned a temp sender that could be clamped to the output line. Bill thought that was an excellent idea and said he would look into it. I don't know how far any R&D has gone on this but it is something to think about.
Phil

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'99 D3500, auto. ,2WD,3. 55 LSD, all options, Banks Power Pack w/K&N filter,DTT TC & VB, Mag-Hytec pan, '99 40ft. Alfa Gold Triple-slide 5'er

 

[Gary - K7GLD]

Well, the senders aren't all that expensive, and the external mount to the fluid line exiting right at the transmission would seem worth a shot for the fun of it. If I use the same approach as used in solid state heat-sinking, I would think a good application of heat-sink compound between the line and the sensor with the whole shootin' match secured to the line with copper strap for heat conductivity, then wrapped with a layer of fiberglass insulation, and then finally a couple of layers of aluminum foil followed by either hose clamps or hi-temp tape should do a decent job - plus, I think it would be a good idea to wrap the above for a distance of 4-6 inches on the side away from the transmission and sensor in order to avoid temp variations caused by the lines exposure to airflow while in motion.

Think I'll give it a try - I'm cheap... #ad


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http://community. webshots.com/user/davison71 Early '91 250, 727 AT, 307 rear... Banks Stinger exhaust, intercooler... US Gear OD... Tweaked pump, upgraded radiator... MORE than a match for every new PS Ford encountered so far...

"Dura" WHAT? NOW I know where all those recycled beer cans go...

 

[EMDDIESEL]

You will never get an accurate reading unless the sender is exposed to the fluid directly. The transmission lines are aluminum which will spread the heat out all over the lines and dissipate it to the air over the entire length of the line. Even if you covered the line completeley, the outside of the line will never get as hot as the fluid itself, so once again, you will be getting nothing more then an Average tempature reading so it is pointless to even try. Spend the $40. 00 and the 30 minutes and do it right. Your transmission will thank you. Believe me, if there was a Temp sender that could get an accurate reading through aluminum, they would already be marketing it. And also, if you strap a brass sender to aluminum line with copper strapping, you will have pinholes in the line within a few months due to electrolytic action. That is no joke, that is why they make Dielectric unions in plumbing. Just warning you ahead of time

 

[illflem]

Gary, after attaching the sender on the outside of the tube temporarily I found it to be way less than ideal, I feel you would be wasting your time with it. Ask your question of Bill K here. He told me the center test port on my '95 was fine for a sender, there may also be an easy spot on your first generation AT.

 

[Gary - K7GLD]

(sigh!)

OK - you guys have convinced me away from my cheap/experimental nature... #ad
I'll plan to do it the PROVEN and correct way! #ad