Transfer box overheating

[Annee Grenadier_girl]

Hi all !
As I’m now on my African adventure through South Africa, Botswana and Namibia I had the warning orange light come up yesterday for the transfer box overheating, now it has done this once before and I took it to Ineos and Steve at Portsmouth found no issue at all and put it down to a sensor issue, however, I was driving for 6 hours yesterday doing about 110kmh and after 5 hours the warning light popped up again, I checked the temp and it was at 118 so turned the engine off for 5 mins, restarted and it was at 85 and dropped further to 82 if I keep my speed a little lower, obviously oil wouldn’t cool that fast so I’m also inclined to think its a censor issue but with many long roads ahead of me over the next 7 weeks I’d welcome your thoughts, Logsplitter has been great and said his went into the red once so I’m thankful that mine didn’t, have any of you in other hot countries had this issue…The Karoo in SA was 33 degree yesterday and its only hoping to get hotter the further North I go.
Many thanks
Annee

 

[Commodore]

I have been in very hot weather here in Southern California and have not had that problem. Sounds like a sensor to me. Any chance you can pick up a Pyrometer and point it at the transfer case? That would go a long way to verifying the actual temperature.

 

[anand]

Were you driving with the center diff locked or unlocked?

 

[LWA55DAL]

I would suggest a T Case oil change just in case you have other issues in the case and in the event the oil has been overheated. It is about a 5 min job and both the fill and drain plugs are easily accessed without removing anything. I would also be interested to see the temp difference between the T case and Transmision. My transmision runs around 170 deg F and the T case around 120 deg F at normal highway speeds with weather in the 70-80 deg F range. Before I changed the T case oil I was getting to 140 deg F, but not throwing a warning.

 

[anand]

I would suggest a T Case oil change just in case you have other issues in the case and in the event the oil has been overheated. It is about a 5 min job and both the fill and drain plugs are easily accessed without removing anything. I would also be interested to see the temp difference between the T case and Transmision. My transmision runs around 170 deg F and the T case around 120 deg F at normal highway speeds with weather in the 70-80 deg F range. Before I changed the T case oil I was getting to 140 deg F, but not throwing a warning.

If I'm not mistaken this is only a partial drain/fill not a full change of the t-case fluid as it isn't getting the oil out of the cooler/lines, correct?

 

[Clark Kent]

Hi @Annee Grenadier_girl

Some good suggestions above. Possibly a sensor problem, particularly if this is a repeat episode. Less likely but it could also be a low oil level.

I don't know what your driving conditions are like so to eliminate it as a possible cause I suggest you take a look at the transfer case oil cooler located in the left wing, below the headlamp. The cooler is a small aluminium radiator and it should be clean and unobstructed by dirt, mud, grass or rubbish (paper, plastic, etc.). You can see it best from the front but can also see some of the back through the slotted wheel liner.
If the cooler appears dirty or blocked you will need to clean it out. Any reasonable mechanical workshop could assist.

 

[Annee Grenadier_girl]

I have been in very hot weather here in Southern California and have not had that problem. Sounds like a sensor to me. Any chance you can pick up a Pyrometer and point it at the transfer case? That would go a long way to verifying the actual temperature.

View attachment 7883875

I can certainly try whilst I’m here in Johannesburg for the night, Thank you

Were you driving with the center diff locked or unlocked?

Unlocked, was just travelling on very long straight tarmac roads.

 

[Annee Grenadier_girl]

Hi @Annee Grenadier_girl

Some good suggestions above. Possibly a sensor problem, particularly if this is a repeat episode. Less likely but it could also be a low oil level.

I don't know what your driving conditions are like so to eliminate it as a possible cause I suggest you take a look at the transfer case oil cooler located in the left wing, below the headlamp. The cooler is a small aluminium radiator and it should be clean and unobstructed by dirt, mud, grass or rubbish (paper, plastic, etc.). You can see it best from the front but can also see some of the back through the slotted wheel liner.
If the cooler appears dirty or blocked you will need to clean it out. Any reasonable mechanical workshop could assist.

Thank you, I do have a service kit with me and a mechanic is going to service it when I’m further North and before I head into Botswana so will definitely show him this, much appreciated.

 

[landmannnn]

If the transfer case oil were at 105C then the outer casing would be roughly at that temperature. At above the boiling point of water, if you go underneath you would be able to feel that heat with your hand near the transfer case. Squirt some water on it, if it boils off the sensor is right. If not you could gauge the heat by touch, carefully!

 

[bemax]

I had an overheating transfer case once. But I was travelling (at more or less) full speed for half an hour. The temperature rose over 120 degrees. It cooled down within less than five minutes while driving slower (100 km/h). My dealer told me that that had occurred to another customer as well.
while it’s one thing to loose cooling at full speed it is far more annoying to work with it at normal cruising speed.
Did you check whether there is something blocking the air from the transfer case? For example mud or a protection plate that lowers the air flow around it?

 

[LWA55DAL]

If I'm not mistaken this is only a partial drain/fill not a full change of the t-case fluid as it isn't getting the oil out of the cooler/lines, correct?

That is correct. The system holds something like 3 liters and the drain fill is only 2 or so. Still better than nothing and you can laws do it again after a short period of time to try and change more. I haven’t seen a procedure to drain the entire system but likely need to flush the lines and cooler to accomplish that.

 

[Cliffy]

Are your tyres all the same size snd pressure? Do you have a heavy load on rear?
With all wheel drive vehicles, rolling diameter front to rear is important. A heavy load in rear will squash tyre and reduce rolling diameter. This causes slip in thr transfer case and generates heat. It maybe that you need in inflate the rear tyres greater then your front tyres to increase the rolling diameter.

 

[Tinerfeño]

A heavy load in rear will squash tyre and reduce rolling diameter.

Actually not, or at least so little that it has no practical effect. Radial tyres have steel belts on tread. This can not compress or elongate any measurable amount depending on pressure or load on tyre.

It maybe that you need in inflate the rear tyres greater then your front tyres to increase the rolling diameter.

For heavy load additional pressure is needed to reduce heating of tyre side walls due to hysteresis of rubber, not for rolling diameter. Higher pressure also reduces rolling resistance of tyre.

 

[Cliffy]

I am under the impression that, lower pressure creates a lower ride height and therefore a lower radius. Thats how some TPMS systems work. (Measure the difference in tyre rotation to determine if a tyre is deflated)
The test would be to lower the air pressure on one axle. Mark all tyres at say 12 o’clock then drive in a straight line. Stop and check where the lines on the tyres are. If im correct, one axle should of rotated more then the other.

 

[Commodore]

I am under the impression that, lower pressure creates a lower ride height and therefore a lower radius. Thats how some TPMS systems work. (Measure the difference in tyre rotation to determine if a tyre is deflated)
The test would be to lower the air pressure on one axle. Mark all tyres at say 12 o’clock then drive in a straight line. Stop and check where the lines on the tyres are. If im correct, one axle should have rotated more than the other.

I’m pretty sure it just measure air pressure. In the old days when TPMS sensor first came out and they were a nightmare we would put them in a sealed PVC pipe with Schroeder valve installed and pressurize the tube. Put the tube in the trunk and the car computer was happy that all the tire were at the same pressure.

If the system worked as you described then the TPMS would freak out if you drove in a round about because the inside wheels would have to travel a shorter distance.

 

[Cliffy]

Sorry, should have clarified. Some other manufacturers used a system of using tyre speed rotation to determine is a tyre was flat.

 

[Ovrland Bill]

Sorry, should have clarified. Some other manufacturers used a system of using tyre speed rotation to determine is a tyre was flat.

Yes, as a cheaper alternative to TPMS Sensors.