Built Allison getting hotter than normal

B.A.Ram

B.A.Ram

A Big Deal
Trans in my truck was built by Mike L out in California - shipped a whole unit to me and we swapped them out. Everything's been great up until this morning when I noticed the temp got to 222 on my commute to work. Hottest I've ever seen it get prior to this was 205. Checked fluid while running in park and it didn't smell ****y but it was way real frothy and well above the hot mark. I haven't changed the fluid or the filter since I installed the trans which was in April of 2013. What are the basic items to check for to determine why it's getting hot. Obviously a filter and fluid change would be the starting point. Anything else? Check the coolers and make sure they are free of dirt and debris? Wasn't sure if there were some common things to look at on these trucks.
 
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The cooler by the tank is the fuel return cooler. There's the main cooler and one in the radiator. Check the main one for debris, change the fluid using a genuine Allison spin-on (leave the in-pan one be), if it had the oe pan 2 gals will do it.
 
JD4440 said:
The cooler by the tank is the fuel return cooler. There's the main cooler and one in the radiator. Check the main one for debris, change the fluid using a genuine Allison spin-on (leave the in-pan one be), if it had the oe pan 2 gals will do it.
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Why do you say let the in pan filter be?
 
Allison's will run hot if overfilled at all. I'd change the spin on and get the level a bit below normal and see how it acts.
 
IdahoRob said:
Allison's will run hot if overfilled at all. I'd change the spin on and get the level a bit below normal and see how it acts.
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I read that but I haven't messed with the fluid since I filled it up a year ago and this is the first issue with high temps (on edit, I'm assuming it was just reading high this morning b/c it was hot and frothy. I'll check when its cool to see what it reads then but I'm assuming it's at the right level). I run around your level 5 max effort tune on a daily basis so nothing new in terms of driving habits either.

Where is the main cooler, sandwiched up with the radiator and intercooler? Also, it's been so long since I've messed with it I can't remember what fluid I put in it but if remember Mike said to run the standard recommended ATF and not synthetic.
 
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There are two coolers, one in the radiator and the other just in front of the radiator. Take the lines from the transmission and follow them along side the engine and you will find them. Remove the lines from the radiator cooler and look for anything blocking the lines in the fitting area of the cooler. If you find small paper like pieces that would be clutch material coming from the transmission or torque converter. If you find these type pieces you need to remove the radiator and have the oil cooler flushed out in it and you should have the same done for the cooler that sits in front of the radiator. Another good thing to do would be to remove the spin-on filter then cut the outer metal part off and look what is inside of it. This will tell you alot about the health of your transmission. If the spin-on has a bunch in it then remove the pan next and replace the internal filter as well.
 
Diesel Tech said:
There are two coolers, one in the radiator and the other just in front of the radiator. Take the lines from the transmission and follow them along side the engine and you will find them. Remove the lines from the radiator cooler and look for anything blocking the lines in the fitting area of the cooler. If you find small paper like pieces that would be clutch material coming from the transmission or torque converter. If you find these type pieces you need to remove the radiator and have the oil cooler flushed out in it and you should have the same done for the cooler that sits in front of the radiator. Another good thing to do would be to remove the spin-on filter then cut the outer metal part off and look what is inside of it. This will tell you alot about the health of your transmission. If the spin-on has a bunch in it then remove the pan next and replace the internal filter as well.
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Thanks guys - I'll start going through it tomorrow. Hopefully there's nothing wrong with the trans itself b/c that's going to be a chit show given the age and horsepower level of the truck. I'm assuming since it's shifting fine it should be something simple.
 
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Update - pulled the spin on filter and it was pretty dirty. Had quite a bit of metallic sludge but no big pieces. I'm assuming there was residual in the lines from when the original trans was failing as we didn't flush the lines when we swapped them out. Still gets hot but not as quick so next step is to pull the radiator and external cooler. Instead of cleaning them what about swapping a mishimoto radiator and upgraded trans cooler with electric fan? Anybody use their products? Not sure how hard it is to properly clean the originals but I'm assuming they are clogged with material.
 
I would drop the pan and clean it and replace the internal filter if you found that much in the spin on. Cheap insurance and will let you see what's in the pan. If there is a bunch of metal there your in trouble already. The lines and cooler are a good idea but better find out first if it's a failing transmission behind it all.
 
And now we've got shifting issues and a p0700 code. My CTS won't read the TCM codes - any other way to pull them without a tech 2? It started clunking 1-2 shift then would clunk in park and reverse and then started flaring shifts and not going into gear then check engine light and it was useless. Had to clear the p0700 code twice to make it home. Torque converter seemed to shutter slightly when locked in 5th gear accelerating and then didn't seem to lock at all after code was thrown.
 
To add - sitting in driveway and it would not go into reverse or drive unless I turned the truck off and restarted it. It would just act
like it was in neutral. Not sure how these issues are related to the overheating but this is fantastic from a newly built trans from Mike L that's a little over a year old
 
SmokeShow said:
Have you called Mike to get his help?
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Yep - first call was check the fluid to make sure it's not over filled despite explaining it had run normal for a year with no heat issues so don't think fill was the issue. Now it's the weekend so can't get a hold of him. He's not exactly the easiest guy to get a hold of or talk to....I'm gonna try and get my hands on a tech 2 to pull codes so I'll have a starting point
 
Pan's clean other than basic metallic crap on magnet - gonna put a new filter in it and fill it back up. Hoping maybe NSBU switch is bad which is why it's shifting chitty and trans cooler needs to be replaced to eliminate heat issue.
 
Opened suction filter up and it had some metal flakes but assuming they are from old trans. Put a new NSBU switch and did nothing. Won't engage reverse or drive just flashes shift range inhibited. Also took trans cooler out and blew out lines and didn't seem to be blocked so heat issue is in the trans somewhere. Not real sure where to go from here. Called Mike and he's looking up the codes but all I've got is a p0700, b2615, and c0040. Best I can tell the 0700 is just the TCM telling the truck to throw a check engine, the b2615 is a code for the lighting on the passenger side so assuming unrelated and the c0040 is an abs sensor. No trans specific codes at least with the auto cal and the edge cts. Looks like this is going to be a flustercluck.
 
B.A.Ram said:
To add - sitting in driveway and it would not go into reverse or drive unless I turned the truck off and restarted it. It would just act
like it was in neutral. Not sure how these issues are related to the overheating but this is fantastic from a newly built trans from Mike L that's a little over a year old
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It's not the first of his to have issues and it will not be the last. People think they will handle all kinds of power forever and they will not. It all boils down to how he handles it from here out. The metal after a year would not be an old transmission build. If it was from that it would have happened within the first month of driving. The issue is from this transmission. P0700 just signals that there are transmission codes.

b2615 is a code from the Body controller Passenger Compartment Dimming 2 Circuit

c0040 is a code from the Right Front Wheel Speed Sensor

This two codes will no effect the transmission but will affect the brakes.
 
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