Anyone else have a temp gauge installed to give me some ideas on normal readings? First couple of days driving it seems like at highway speeds with the converter locked up it hangs right around 170. With the converter unlocked it quickly (and I do mean quickly) jumps up to around 185. Once the converter locks back up, down goes the temp to around 170. Seems to stay around 180 +- around town/traffic driving also. This is in 95* weather and no mods to the transmission. She's just like it came from the factory. Haven't seen anything over 185 yet. I was surprised at how fast the temp changes during different driving conditions. You guys experiencing about the same thing?

 

That looks normal to me. The temperatures will come down a bit once the weather cools.

Mark

 

Check this out. On my 18 mile drive to work this morning with 68* outside and 60mph for 75% of the drive the trans temp barely broke 135. Does that sound right?

I can't believe how much of a difference outside air temp makes on the fluid temp. That trans cooler (not the radiator) must really be efficient when it's cool.

 

Galaxy,
did you install an electrical gauge or mechanical. If it was electrical, how do you tap into the ECU for installation? Is it difficult?

 

Sorry, I have a mechanical. I bought the Autometer installation manifold (pn 2287 I think) and tapped in to the 5/16 line coming out of the trans. I think that even the electrical gauges still have temp probe that must be installed in line somewhere to get actual fluid flow. The only difference between the two types of gauges is that the electrical one has wires from the probe to the gauge for ease of installation where the mechanical one has the capillary tubing. Still not hard to install and the mechanical ones are much more accurate.

 

Galaxy,
Search by my id for some history from last year.

Summary: Stock, In Phoenix summers mine would run ~195F on the freeway (110F ambient).

Today, I can climb a hill (110F weather) and not break 170F.

For the stock cooler, your temps seem perfectly normal.

By the way, I have a 20 minute drive to work (yes, 80F mornings) and the trans will run ~125F.

The only time my trans gets hot (if you call 180F hot) is when someone slows me down climbing hills.

Tony

 

The last thing the oil does before leaving the transmission is go thru the Torque Converter -- which is the largest heat-generator in the transmission, so...

...that's why you see instantaneous temperature rise when the torque converter unlocks.

 

Thanks F150Tony for the info. Man, today on the way home the converter unlocked due to headwinds and stayed that way for only a couple of miles and the temp went all the way to 203. I stayed at 70mph and turned off the o/d and the temp immediately fell to 180. I can't believe how drastic of temp changes you get in this thing. It's fun just to watch the gauge work.

BTW, I have not changed the fluid. Still running factory install so, what would you guys say is too hot and should shut her down? I don't tow anything and that 203 temp was just from the converter unlocking while in o/d. I know I could turn it off to cool it down but what that too hot? I am planning on changing to Amsoil fluid around 15,000. Would a Trans-Go shift kit keep temps down when under a load or not really?

 

Just received an trans temp gauge which is electrical. Does anyone have experience with installing the sender? I thought with the electrial, one could just tap into a trans line, but turns out ITS the mechanical gauge that does this.

My trans is the 4R70W and have read, in other posts, that the sender could be installed in a service port on the side the trans?? Will this work and if so where and what service port? Or, do I have to bite the bullet and go to a shop to have the pan taken off, a hole drilled, taped and then have sender welded to it?

 

Never! If it gets too hot, which in my book is over 230F, idle in park or nuetral. NEVER shut off the engine while the transmission is too hot. That will cook the transmission. You need to keep the fluid flowing to cool it.

There is a port on the driver's side of the transmission. It has a pipe plug in it, and it's a 1/8 NPT thread. It will give the same temperature readings as installing the sender in the pan.

 

Mark,

TNX for the info on temp readings!! Will go this route rather than the pan method but just want to be sure about where it is!

I'm not exactly sure what a pipe plug looks like? Is it located near the top and front of the pan?

I have the Ford Workshop Manual and could it be the "line pressure tap"?

Will have to get under the truck and have a look tomorrow during day-lite.

 

I don't want to start another temp sender placement war!

I haven't experienced it, but I have heard from others on this board that the pressure port will read >15F lower than the fluid in the cooler lines.

As far as the electrical sender, I did not run a ground. I ohmed the cooler line and found it to be less than 0.4 ohm. More than adequate for this application. If you would feel more comfortable, by all means run a separate ground wire from the sending unit location to the chassis.

I used a brass 'T' and flare fittings from the local hardware store. No leaks, after ~18 months & ~20k miles of mixed driving city, freeway, and towing.

Shift kits will only help with slip during shifting. IMHO, unless you are intested in tire squealing shift (slight exaggeration), don't bother with the shift kit. THE SINGLE LARGEST HEAT GENERATOR IN THE TRANS IS THE CONVERTOR!

As I mentioned (pobably in another post), you may need to experiment with a couple of different coolers before you find one appropriate for your application.

As a rule of thumb, every 20F rise in trans fluid temp is a half life. In other words, trans fluid is designed to last 100k miles at 170F. At 190F it will last 50K. At 210F it will last 25k. At 230F it will last 12K. You get the idea.

As Mark said, if the trans does get that hot, shift into Park or Neutral. Idling in any gear will slowly increase the temp. Out of gear, the convertor stops slipping and therefore stops generating heat. Literally allowing the trans to cool itself.

Hope this long post helps!

Tony

 

That's the one.

This port and the pan will read the same temperatures. The line to the cooler will read anywhere from a few degrees to almost 100 degrees hotter than the pan. It all depends on what temperature you want to see.

I like to see the bulk transmission temperature. I know that it isn't the hottest part of the transmission. I think it is the best indicator of how the transmission is functioning. YMMV.

Mark

 

Hummmm…… That’s interesting to know about the TC and the temp of the fluid in the “out” line. I can understand wanting to know the maximum temp of the fluid, but if the max temp is not reached until “after” it’s done it’s job inside the tranny, then goes to the TC and gets even hotter, then you could almost argue that it might be better to know the temp of the fluid going “in” the tranny after it’s gone through the cooler? That way you would know how hot it is “before” it sees any seals and internal workings (sending unit in the return line).

But then, knowing the temp of the fluid “as” it’s working would also be a good thing to know (sending unit in the pan or service plug). If it’s too hot before it even reaches the TC, then isn’t that where all the problems occur with overheating?

I’m wanting to put in a trans temp gauge because I’m now towing a #4500 travel trailer. Been debating on the location of the sending unit. Tapping into the line seems like a lot of work, but gives you the “hottest” temp. Using the service plug is easy, but only gives you the internal temp of the fluid. Installing in the return line tells you how hot the fluid is going in.

I know this has been debated to death, but I was not aware of the TC being the last point of the fluid before it heads to the cooler. I thought it was the first thing the fluid sees coming into the tranny.

I guess we need three gauges!! One after the cooler, One before the cooler and the last one inside the tranny!

 

All Done!

About 3hrs as I took my time with routing the wires here and there. Using the "line pressure tap" is a piece of cake. It's the only smallish looking drain plug there. The letters LINE are right beside it! Had to be ready to put the sender in quickly as some fluid will come out. Used a bit of Teflon tape towards the back of the threads for a good seal.

As it turned out, the sender was the easy part. Finding a 12V source that works with the ignition was the real pain! From prior experience I know that anything from the fuse box is not switched, ie there is 12V's ON all the time. I loosened the cowling above and the panel below the steering wheel. I was now able to see what wires where available. I started using a test light and by turning the ign. on and off, I checked some wires in a harness going to the steering wheel. Now this can be very, very dangerous!!! I have a 2000 F150 with Ford's anti theft security system, cut the wrong wire and the truck won't be moving for awhile!!

Eventually I found a green wire with a yellow stripe. I disconnected the neg side of the battery and peeled some of the insulation away so it would stay in one piece. I then soldered the power lead for the meter to it.

For the light in the meter, I pulled the light switch out of the dash and found a blk wire that would work accordingly to the switch.

During the test drive, it took the meter some time to register any temp above 100F but it began to rise and settled in at a hair under 150F. The outside temp here north of Toronto was 66F (19C).

From reading other posts and considering air temp and no TT behind, I concluded that this is as accurate as you can get. Sure you could have 3 more gauges, 1 in the pan, 1 in the out line and another after the cooler but I would find that confussing!! I just need a ballpark figure so I'm happy with the instillation.

And no leak from the sender!

Thanks to all for their opinions and help.