Forum Discussion

mountainsam's avatar
mountainsam
Explorer
May 14, 2014

truck temps

Just put a set of gauges in my truck, 05 cummins automatic with Banks Engine Brake. We are headed out Monday for a 6 week cruise around the Midwest from California. GVW should be around 18k. What kind of temps are normal and what would be concerns?
First time pulling this trailer I pulled from Clearlake California to Redding and back last month and the transmission temp high was 154 and manifold temp high was about 870 at 24 pounds boost in the mountains. Flat land it never got over 140/670/4 with cruise set at 55 mph, California max for towing.
Thanks in advance for your feedback

Sam
Tow Vehicles
  • diazr2's avatar
    diazr2
    Explorer
    May 14, 2014
    Boy those temps sound low to me. You should have no problems at all if you get that kind of temp. Even if it gets over a 100 you should still be very low on temps in the truck. That part of California are in the tipple digits for the next few days but I don't think the high temps will last. At any rate you should be good to go.
  • beaslwd's avatar
    beaslwd
    Explorer
    May 14, 2014
    Sam, where is the trans temp taken, Outlet line to cooler? in the Pan? it makes a difference in the temp of course. On our last Dodge an 03(3500) with a mild upgrade the temps were IIRC a lot higher, trans going down the road 170's, EGTs climbing the Siskiyus I had to back off to get the EGTs below 1200, and boost would run somewhere around 22 pounds.
    So it sounds like your doing fine with those temps, although Clear Lake to Redding is not very mountainous IIRC?? Try Clear Lake to Salem Or for some hills LOL
    Good Luck and have fun on your trip:)
  • srt20's avatar
    srt20
    Explorer
    May 14, 2014
    Yeah those temps are awfully low. Mine is hotter than that just driving it to town with no load.
    I'd like to know where the sensors are.
  • wcjeep's avatar
    wcjeep
    Explorer
    May 14, 2014
    Where is the EGT temp? Pre or post turbo? Last I read automatics have seconds to live when above 250degrees. Under 200 degrees is preferred. If your EGT is preturbo your running cool. Keep the EGT under 1200deg preturbo. Technically your engine should have no problem with 1200deg preturbo. However, there is manufacturing differences from gauge to gauge. Did you monitor the back 3 cylinders vs the front 3 cylinders? I prefer not to run my equipment at 100%. Keeping it under 1200deg preturbo would be considered safe.
  • thomasmnile's avatar
    thomasmnile
    Explorer
    May 14, 2014
    srt20 wrote:
    Yeah those temps are awfully low. Mine is hotter than that just driving it to town with no load.
    I'd like to know where the sensors are.


    OP doesn't say what ambient air temp. was where he was driving.
    My 05 3500 typically runs 160-180 transmission temp in 70 to 90 degree ambient temps (temp sensor is in the pan) and 190-210 degrees coolant temp in the same ambient range.
  • mountainsam's avatar
    mountainsam
    Explorer
    May 14, 2014
    Transmission temp is taken from the inspection plug opening just above the pan. The EGT is taken directly off the exhaust manifold between third and forth cylinder. The ambient temp was mild, in the mid 70's on the first trip. I will have higher temps this trip going from California to Michigan and back.
  • Colorado71's avatar
    Colorado71
    Explorer
    May 14, 2014
    That is some low EGT's. I get in the 1300's, briefly, just putting my foot down to pass, but that's with Smarty level 9. Haven't towed with the monitor yet.

    Hell, even just driving along at 65 or lugging it around my neighborhood it gets to 700-900.

    It's a manual so no trans temps sensor.
  • thomasmnile's avatar
    thomasmnile
    Explorer
    May 15, 2014
    mountainsam wrote:
    Transmission temp is taken from the inspection plug opening just above the pan. The EGT is taken directly off the exhaust manifold between third and forth cylinder. The ambient temp was mild, in the mid 70's on the first trip. I will have higher temps this trip going from California to Michigan and back.


    Think your tranny temp was fine at that ambient temp. I don't have an EGT monitor so I don't have a clue. Used to pull a 12000 pound fifth wheel and never melted the pistons so I was happy..........;)
  • ib516's avatar
    ib516
    Explorer II
    May 15, 2014
    FYI. All you are reading is the temperature of the transmission case, that's why it's reading so low.

    From a 48RE Transmission expert

    "Where to install the transmission temp sensor is one of the most frequent question and discussions I have with guys. My question to you guys is this, why are you buying a gauge?

    If you are buying a tranny temp gauge just so you have one and you can tell your friends you have one then you can pretty much put it wherever you want, as it really doesn’t matter in that case.

    To me, a gauge is there to monitor tranny temps and indicate how often to change the oil. If you want a gauge for what I consider to be its primary functions then lets look at the oil. Oil temp is what we are trying to monitor so keeping that in mind lets look at the common places people install their gauges and what they are learning by doing so. Decide for yourselves where you want to monitor your tranny temps from and at what cost.

    First lets deal with when and why tranny oil gets hot. Most will agree that trans temps are the hottest in stop and go traffic when the transmission is in first or second gear or in the reverse position, in most cases when trying to back up a trailer.

    One of the favourite locations by people is the front servo on the passenger side of the transmission. The problem with that is there is no oil in that port in first gear, 2nd gear, or reverse so what are you measuring?
    If you do have a transmission temp sensor in that port, take it out, not only is it not monitoring your oil it is probably causing damage to the transmission as the probe is most likely making contact with the servo spring.

    Middle port passenger side better known as accumulator port is another, while this port does measure transmission temp in first, second, drive and od, it is measuring stagnant oil. It other words oil fills up and stays there. There is no oil present in the accumulator while you are in the reverse position. So it is useless to measure from this location also.

    Another favourite place is in the reverse port on the passenger side. This port only has oil in the reverse and manual low positions. This means no oil in the in the drive position. I have had guys phone me arguing with me that they are seeing temps of 200 degrees while driving down the road in stop and go traffic when measuring from this port. My comment to that is congratulations we now know the temps of your tranny case, we can only guess at this point what your tranny temps are.

    As far as I am concerned, there is only one location to accurately measure your tranny temps from. That is your transmission cooler outline. I have seen temps get as high as 300 degrees coming out of that line. That line sees every 20 seconds 1 quart of oil pumped through it at 1100 rpms. 3.8 gallons at 2100 rpms every minute, in 3 minutes you have pumped out basically 12 gallons of oil. So lets say you see temps of 300 degrees from this line and you have pumped it through your tranny At this point in time you can change the oil in your tranny or you can wait a little longer and change your tranny , rest assured you will be doing one or the other. I don’t make any extra money selling you guys the Chrysler lines, I give you the number we use, 5011244AA. The 1995 and earlier trucks it is a little more difficult to hook up the tranny temp gauge, but the 96 and later trucks you guys only have one choice, use the Chrysler line if you tow and want an accurate reading. To me, a gauge is there to monitor temps and indicate how often to change the oil..."
  • thomasmnile's avatar
    thomasmnile
    Explorer
    May 15, 2014
    Wouldn't say totally useless. My mechanic told me the stock transmission temp monitoring on my 05 doesn't activate the dash warning light until the fluid temp hits 280 degrees and that may be a tad late. When towing our fifth wheel the only time things got dicey was towing in the hills East of San Diego area heading to I-8. Saw 220 on the gauge and could SMELL it briefly, but the light never came on. Once off the steep grades all was fine and temp settled in around 180, ambient temps were high 90's.

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