Aisin overheating under load

[teasac69]

Have 2014 3500 Limited 4x4 crew can. The Aisin keeps getting to warm in my opinion. I’m pulling 42’ fifth wheel TT at 18,500 lbs (well within limits) and on moderate hills and flat ground I’m hitting 220 fan starting around 210.

I’ve serviced all fluids with synthetic, replaced the bypass with aftermarket, cleaned all coils as best I can. Changed t stat

I owned a 2016 exact set up and she never got more than 180 even in the Rockies. I’m out of ideas. Talked with several about deep pan but they all agree until we get real cooling the big pan will just delay the fluid heating but will get there.

help??? I smoked a 68 RFE in the Rockies in 2014 and it’s got me gun shy.

thought about an electric fan cooler placed elsewhere but don’t know what to do.

 

[DHayden]

Do you have a winch/bumper that might be obstructing/rerouting airflow?

 

[teasac69]

No obstruction. No bent fins no dirt clogs

 

[gsbrockman]

Have 2014 3500 Limited 4x4 crew can. The Aisin keeps getting to warm in my opinion. I’m pulling 42’ fifth wheel TT at 18,500 lbs (well within limits) and on moderate hills and flat ground I’m hitting 220 fan starting around 210. Kinda confused......so the previous temps ARE your transmission fluid temperatures or coolant temperature?

I’ve serviced all fluids with synthetic, replaced the bypass with aftermarket, cleaned all coils as best I can. Changed t stat What transmission fluid are you running? What transmission filter brand are you running? Are you also referring to the TBV (thermal bypass valve) ?

I owned a 2016 exact set up and she never got more than 180 even in the Rockies. I’m out of ideas. Talked with several about deep pan but they all agree until we get real cooling the big pan will just delay the fluid heating but will get there.

help??? I smoked a 68 RFE in the Rockies in 2014 and it’s got me gun shy.

thought about an electric fan cooler placed elsewhere but don’t know what to do.

Can you clarify questions above ?

 

[kthaxton]

Yeah, I'm confused too, in the other thread you said:

"I pulled 42’ fiver with 68RFE into Rocky Mtn Natl Park but coming out through Central City I smoked that bugger so bad they could only use carcass to rebuild. Got home and bought Aisin never looked back. Pulls my 18,500 TT never getting above 180."

Are you calling your truck an "Aisin"? (if so, why?)

 

[High Voltage]

Are you talking about your trans or the engine, my trans ( Aisin ) has never been above 185, but the engine will run 200 / 225 when pulling grade with 5ther and boat in tow
18K +/-. And when that fan comes to life. wow!!

 

[AH64ID]

Are you sure the torque converter is locking?

If you live in the Rockies and replaced the trans thermostat with a Bypass I’d go back to stock. You’ll have more issues with cold fluid than hot fluid.

 

[Cummins12V98]

35k combined even in HOT weather I am usually 165-172.

you have a problem!!!

 

[teasac69]

Can you clarify questions above ?

sorry for my confusing message. The temp I’m talking about is transmission. Plus whomever asked why I’m calling my truck Aisin is referring of course to the type of transmission vrs 68RFE.

 

[teasac69]

Are you sure the torque converter is locking?

If you live in the Rockies and replaced the trans thermostat with a Bypass I’d go back to stock. You’ll have more issues with cold fluid than hot fluid.

I live in east Texas but travel to the Rockies. I replaced the engine t stat but the transmission fluid line forward to the cooler has a factory installed bypass to help transmission to warm up faster just returning fluid until it’s warm then the valve opens and goes to normal flow. I researched my heating and several folks suggested that by pass might be malfunctioning so I removed it. Nothing changed.

 

[teasac69]

Yeah, I'm confused too, in the other thread you said:

"I pulled 42’ fiver with 68RFE into Rocky Mtn Natl Park but coming out through Central City I smoked that bugger so bad they could only use carcass to rebuild. Got home and bought Aisin never looked back. Pulls my 18,500 TT never getting above 180."

Are you calling your truck an "Aisin"? (if so, why?)

Bought truck with Aisin. Worked like a champ with towing in mountains under load and never exceeded 185 transmission temp. That was my loaded 16 but tried to downsize and truck sold quickly trailer never sold so trying to get back there.

 

[teasac69]

Are you sure the torque converter is locking?

If you live in the Rockies and replaced the trans thermostat with a Bypass I’d go back to stock. You’ll have more issues with cold fluid than hot fluid.

Not sure how to know if torque converter is locking???

 

[gsbrockman]

sorry for my confusing message. The temp I’m talking about is transmission. Plus whomever asked why I’m calling my truck Aisin is referring of course to the type of transmission vrs 68RFE.

And there’s still more unanswered questions that I addressed....

 

[teasac69]

Sorry I did not see the expanded area.

my local transmission shop used synthetic fluid for this truck not sure of either brands. Yes the TBV is the bypass I’m referring to. And the temps are trans. The engine temp runs between 195 and 210 towing.

 

[lpennock]

Not sure how to know if torque converter is locking???

You will need an obd scanner such as AlfaOBD or Edge CTS that can display real time data. There are PIDs defined for Selected Gear and locked gear. Locked gear is the one you want. CTS actually combines them to show different color when you have the gear pid displayed chosen depending on the state.

 

[TFucili]

Did the issue start before or after the transmission was serviced? Do you know the history of the truck prior to you?

 

[teasac69]

Did the issue start before or after the transmission was serviced? Do you know the history of the truck prior to you?

The heating issue was present since I purchased the truck last fall with 120k mikes. No I don’t know history of this truck but can tell it was used in a dusty environment by the dust in the nooks and crannies.

 

[Ozymandias]

Is accidentally the water/oil heat exchanger at the block bypassed?

 

[teasac69]

Is accidentally the water/oil heat exchanger at the block bypassed?

I have no idea what this means???

 

[sag2]

First thing to check is cooler flow. Once you know that you can get on with further diagnosis if required. FYI there is a cooler bypass check ball located in the valve body.