Auto Tranny pan temp

[Maniak]

What Temp are you guys seeing in the Auto transmission Pan (al4d or 700r4 conversions)? I'm looking for Pan temps, not temps going to the cooler.

I'm hitting between 110F (when its 70 out and cruising) to 140 (in town, 100F outside).. I'm sure this weekend it may go even higher as it should be close to 110F this weekend..

~Mark

 

[Maniak]

Bump and update.....

It was 105F+ over the weekend.. The highest temperature the fluid in the pan got was 160F.. and it stayed there.. Even on the freeway cruising at 70 with OD and lockup (after it had already reached 160f) it still only dropped to about 150-155F...

~Mark

 

[410Fortune]

my A4LD ran between 180 and 215, it was built by Transwerx and has a slightly modified 4.0L OHV in front of it. This was with a 4.0L HD radiator and B&M trans cooler in series, also a custom aluminum pan allowing 2 quarts additional fluid capacity.


My 4r70W now runs at 150 tops. (bigger trans, small truck)

 

[Maniak]

Were those in the pan temps, or fluid temps going to the cooler?

The 180-215 temps seem high for pan temps but the 150 max is close to what I get in the pan (I got 160 when it was over 105F out).

~Mark

 

[410Fortune]

sensor was in the pan, I know those temps are high, but thats what it ran at. 215 was usually while towing, 180 was the norm.

 

[Maniak]

Thanks for the numbers...

I "heard" that my pan temps should be 140 or less and at 160 I should pull over..

After thinking about it, I figured that can't be right.. When its 80F out, freeway driving gets the pan temp to go between 120 and 130 (25 miles or so at 70mph)..

The same trip when its 105+ out gets the temp to about 140 to 150 (I saw 150 after I got off the freeway and drove a mile or so when it was 109F out)..

~Mark

 

[aldive]

I would worry when the temp exceeds 190 F.

 

[410Fortune]

synthetic ATF begins to break down at like 275, regular mercon is 250, below that you should be fine. I would pull over at 220 with the A4LD (happened once, outside Vegas, 100 degrees with boat)

 

[kenr74]

Just curious why the temp in the pan and temp in the lines to the coolers would be so different?

 

[Rhett]

Temp in the pan is right by the source of the heat whereas temp in the lines near the cooler is not quite as close.

 

[spindlecone]

150 max with an oversize PML alum, pan

 

[Glacier991]

yeah I'm with 410Fortune on temps. In a perfect world you'll run 150-170. In the real world you will see 190-210... just change the fluid more often. Strive for lower, but realize it may not always happen. My 93 Sable runs 210 trannie temps on really hot days with AC. I change the fluid once a year. (and keep my fingers crossed, and plan to add a cooler this year).

 

[Maniak]

I now have a good gauge instead of that crappy, sticking b&m gauge.. Now the temps move more like I would expect them to...

Freeway driving when 80F out is 150f
Around Town driving when 80f out is 160f

Around Town when 90f is 170f

Around town when its 105F out is 190f

I do have a high stall converter (actual stall speed is 2700 or so) so I'm sure that isn't helping any, but since there is only a 10 degree difference between freeway (locked) and town driving I'd say my 2 coolers are working ok.

I've always wondered how the tranny fluid is supposed to stay at 150-170 when it goes through the radiator which already has hot water in it..

I also noticed that the exhaust pipe is problably heating up the pan sine it sits just in front/below the pan.. I'm going to put exhaust wrap on the cross over pipe to try to keep some of that heat away from the pan.

~Mark

 

[410Fortune]

my V8 pan temp gets to 150 max now...normal is about 135, outside temp has alot to do with it!

as long as you have an inch or so of airspace between the exhaust and pan you should be fine, but every little bit helps.

I noticed my temps rose slightly when I re-installed my plastic fender skirts, time to drill some holes

 

[Bronco638]

I know we're talking pan temps but I recently installed a temp gauge and remote filter. The filter base (w/probe) is up near the radiator so that's about 3 feet of travel between the tranny and the base. I saw a max temp of 165º while letting the truck idle in a parking lot for 20+ minutes. This was after driving at highway speeds for 30 minutes. At speed, the temps usually dropped to 145-150º. This is without a cooler, which I plan to install soon. I can't imagine that the fluid would lose too much temperature in those three feet. But, I was surprised, I figured I'd see higher temps, especially while idling.

 

[Rhett]

Is it "better" to have the tranny temp sensor in the pan or in the lines?

 

[410Fortune]

It does not matter where you put the sensor, aslong as you understand what temp you are reading.
I have seen one installed on both sides of the cooling system, this gives you a before and after temp.

 

[Maniak]

I was thinking in the pan since that is the temp of the fluid the tranny is using, but I'm not sure which temp is better to know.. The fluid going into or the fluid going out of the tranny.

I'm seeing 190F into the tranny which I know is higher than optimal, but I'm hoping its ok for around time driving in heat.. But since it is supposed to be 105F+ for the entire next week, that means I'm going to hit 190F in the tranny every day next week.. I wonder if fan on one of the coolers will actually help (I'm thinking no since there is only a 10F difference between highway (locked tcc) and town). Also when its 105F I can really hear my engine fan.. I don't think the clutch ever lets it freewheel at that high of an ambient temp.

~Mark

 

[410Fortune]

Another cooler is your best bet, or a better cooler.
When I went from my crappy pep boys Hayden motorhome unit to a B&M my temps dropped 50 degrees and STAYED lower, the hayden cooler would let it climb.

the stock coolers are pretty good actually, you can run two of them in series and expect the tempt to drop quite a bit!

I had a 10" electric fan right on my trans cooler, I have removed it with the V8 since it runs cooler...wouldhave to hack out the back half of my grill to clear it with this new setup too...
the 10" fan would help, when it got hot, but only when sitting, on the highway it had no effect....

 

[Maniak]

Currently I go from the tranny to the radiator cooler.. From there to a b&m cooler (plate style about 12" by 10") then to a 24000gvwr tube,fin style cooler (much bigger).. The plate cooler sites in front (towards the drivers side) of the 24000 gwwr cooler.. both are in front of the condensor/radiator.

I was thinking of re-routing the fluid and not putting it through the radiator and if that works better, put a temp controlled flow restrictor and run the radiator cooler in paralell of the other coolers so it could help heat up the fluid in the winter.

~Mark