299d2 final drives REALLY hot

[hvguy]

Running full throttle moving dirt back and forth at 100% efficiency for about 1hr; I got out to swap to my box grader and felt the drive housing... They were... Hot, I could smell the 2 month old fresh paint burning. Both sides were the same.

How hot can they get? Is this because of the 155 degree hydraulic oil?

Thanks!

 

[lantraxco]

Planet drives, and if integral the hydraulic motors, are each at best 95% efficient, so 5% of the horsepower used, or up to 10% if you include the hydraulic motor heat soaking through the metal has to be radiated by the hub. Too hot to touch is nowhere near too hot for the gearbox, but I would look at changing up the gear lube. Don't know what factory fill is but a full synthetic, or adding a friction modifier if there's no parking brake running in the gear lube are things to consider.

 

[Vetech63]

Pull the drain plugs and see what falls out. Hopefully it’s gear oil and not fine metal particles.

 

[lantraxco]

Pull the drain plugs and see what falls out. Hopefully it’s gear oil and not fine metal particles.

Hopefully something liquid comes out!

 

[Tyler d4c]

Each holds about a qt of 75w140 they do seem to get warm cat says 500 hour intervals if I remember right I try to do mine once a year witch is 50 to 100 hours 2 qt of oils is way cheaper then a final

 

[lantraxco]

Each holds about a qt of 75w140 they do seem to get warm cat says 500 hour intervals if I remember right I try to do mine once a year witch is 50 to 100 hours 2 qt of oils is way cheaper then a final

Is that a full synthetic?

 

[Nige]

Is that a full synthetic?

A full synthetic is what is recommended. See below, especially the two notes under the table. Capacity is listed as 1.0 litres (0.26 US gallons) but I always fill any compartment using the level plugs rather than a fixed quantity. YMMV.

 

[hvguy]

When I bought the machine about 50 hours ago, they changed the oil. It wasn't too bad, but wouldn't hurt to swap it for full synthetic.

 

[Nige]

When I bought the machine about 50 hours ago, they changed the oil. It wasn't too bad, but wouldn't hurt to swap it for full synthetic.

So it doesn't have a full synthetic in it right now.?

How hot is HOT..? Have you shot the temps with a non-contact thermometer.?

 

[hvguy]

No known temp. It was swapped by cat so it's probably synthetic

 

[Nige]

(After checking oil levels first) I'd shoot temps before getting hung up on changing the oil. One would hope that if a dealer did the oil change then they would've put a full synthetic in it.

 

[hvguy]

Next time I'm running it hard I'll bring a thermometer

 

[673moto]

Curious about this too... my finals have been pretty toasty when pushing around mud.
What is too hot?
Also: don’t want to get off track but what if your finals are overfilled?
I just drained exactly 2 liters out of one side... and it looked like it was ATF.

 

[lantraxco]

Curious about this too... my finals have been pretty toasty when pushing around mud.
What is too hot?
Also: don’t want to get off track but what if your finals are overfilled?
I just drained exactly 2 liters out of one side... and it looked like it was ATF.

Overfilled usually means you have a leaking motor shaft seal.

 

[673moto]

Overfilled usually means you have a leaking motor shaft seal.

That sounds like a job I can get halfway done before giving up and sending the final drive off for repair!

 

[673moto]

Back to the original topic:
What is too hot for a final drive to be running at?

 

[92U 3406]

I don't know about those finals specifically but I'd be getting concerned if they creep up to 210F +

250F is the point where oil typically breaks down and damage starts to occur in gear components.

 

[Nige]

As some sort of a guideline in larger equipment fitted with temp sensors in the rear end & finals the alarms start to go off at anything from 120C (250F) upwards.

The fact that a fully synthetic GO is specified as standard for this particular compartment leads me to believe that it probably runs hot-ish even in normal operating conditions. Now that could be down to nothing more than the very small quantity of oil it contains, but I wouldn't bet on it.

 

[lantraxco]

As some sort of a guideline in larger equipment fitted with temp sensors in the rear end & finals the alarms start to go off at anything from 120C (250F) upwards.

The fact that a fully synthetic GO is specified as standard for this particular compartment leads me to believe that it probably runs hot-ish even in normal operating conditions. Now that could be down to nothing more than the very small quantity of oil it contains, but I wouldn't bet on it.

The small quantity of oil just reflects how small the gearbox is, which is the problem. The more horsepower you shove through a small planetary the more heat you get obviously, and the less surface area of exposed metal there is to pass all that heat off to the outside air. Flat black paint will actually help some, lol.

 

[LEGO]

Running full throttle moving dirt back and forth at 100% efficiency for about 1hr; I got out to swap to my box grader and felt the drive housing... They were... Hot, I could smell the 2 month old fresh paint burning. Both sides were the same.

How hot can they get? Is this because of the 155 degree hydraulic oil?

Thanks!

It would be wise to drain the oil and see if any metal comes out, and also how much oil comes out. If its about a quart per final drive then that's a good thing; if its way more than that it could be possible that hydraulic oil is bypassing to the final drive. Regardless, change the oil. CAT part number is 350-9510 for the quart. you'll need two.