Towing transmission Temps

[CEly]

I brought our toyhauler home today to un-winterize it and prep for next weekends trip. Driving through town to our house the transmission temp crept up to 260* then hit 280* (gauge pegged) while maneuvering it to park it. I was in Tow/Haul mode w/EB on. I was driving with a light foot, not like a madman overworking the convertor. I am using the DiPricol gauge w/accutemp adapter on the outgoing transmission line. I realize that the accutemp adapter is going to be slower to respond to actual temps since it is actually a "heat sink". I will be Interstate driving from northern CO to northern NM over Raton pass next weekend and will have a better feel for transmission temp as a whole. Just wondering what other members are seeing for temps.

 

[MA2LA]

that seems pretty darn high. my 48re with a double deep pan has only hit 178 in the pan on the hotest days in stop in go traffic and 8k behind it.

 

[LRutigliano]

I agree with MA2LA.



With my sensor in the PML pan, with the 11k 5er, I'm seeing 140F at freeway speeds pulling grades; 160F at 30 to 40mph pulling switch back grades and up to 190F while manuvering the 5er into the RV Park space.

 

[PVanderlugt]

Doesn't seem unusual to me, mounted on the "out" line fluid is as hot as it is going to get. Of course it is going to be much hotter than in the pan, it travels thru 2 coolers before being dumped back in the pan. That is why we are using these fancy new transmission fluids, ATF4+, etc, they can handle these high temps just fine. most important is the transmission "core"temp, probably pretty close too pan temp, that one shouldn't probably go much above 230 or so damage to seals, gaskets etc. Out line temp better for immediate response and trends, pan probe probably more better indication of actual transmission temp. Keep in mind that reverse is the hardest on everything, largest temp gains. It is not that different from for example the cooling system, gauge might read 190, overall engine is around 190, but there are for sure spots in the cooling system that are a lot warmer then 190 (against the cylinder liner for example) but that really doesn't matter it's the overall temp that matters

pete

 

[CEly]

I'm starting to think I have a guage issue. The last 2 mornings the guage read 120* when I started it in the morning. I wonder if the accutemp is grounded very well on the transmission line. Does it need to be? I know the guage did not do this when first installed.

 

[RVTRKN]

I agree with PVanderlugt, this topic came up at May Madness and both trany experts stated the same, you need to add a gage at the return line and then you can see your temperature trends before and after "delta T". I would ask an expert what the Delta should be but the return line is what you base your trany temp on.



Steve...

 

[JDiepstra]

There must be a problem with your gauge. I don't see over 180 towing 5000 lbs but I have gotten it around 200 plowing. I do have a deep pan.

 

[CEly]

I checked the accutemp with my laser thermometer when I got home and it read 160*, the transmission pan read 157* and the exhaust pipe just in front of the DPF was 250*. I'll investigate the gauge and/or wiring next.

 

[Diesel Manor]

We sell something similar, called the Transcender (don't laugh). The DiPricols do need a good gnd. we've found that the cooler line isn't always a good gnd. source. We've done a little tech sheet here:

DieselManor - Installation Sheets

DieselManor Tech Tip - Supplemental Grounding Instructions for Temperature Senders

that should help. Try running the separate ground to another location on the chassis.

 

[CEly]

Well, I attached a ground wire per the Diesel Manor install sheet and no change in the way the guage is behaving. It still reads abot 130* first thing in the morning on start-up. While towing, it seems to read normal temps (190-210) but in slower in town conditions can climb above 260*