Front Axle Ring Gear Rotation Direction?

[CarbonSteel]

This may seem like a silly question, but the forest and the trees have merged.

The rear axle ring gear rotates towards the front of the vehicle, picking up oil from the sump and slinging it over the top of the pinion gear from the top of the ring gear.

Since the from axle is installed "backwards" does its ring gear pick up oil from the sump and sling it under the bottom of the pinion gear from the bottom of the ring gear OR does it rotate the same as the rear axle (towards the front of the vehicle)?

Try not to laugh too hard when reading/answering.

 

[wwillson]

The front ring gear rotates in the same direction as the rear ring gear. The "front ring gear picks up oil from the sump and slings it under the bottom of the pinion gear" - correct

 

[4WD]

Which is the easiest route and a lower capacity gets the job done …

It also forms a "viscous coupling" …

 

[CarbonSteel]

Ah--that is what I thought and now that I am about to install the "permanent" axle covers, I may need to rethink the temperature sensor probe location for the front axle. I am not sure enough oil will be slung towards the upper part of the axle cover to capture a reading, but then again, I need to spend some time off road in 4x4 mode to see since it has a front axle disconnect which prevents the axles and drive shaft from turning in 4x2 so the oil is not moving anyway.

Thanks guys!

 

[Zaedock]

There are channels cast in to the housing that help channel gear oil to the pinion bearings (primarily the outer). These channels are especially important in High Pinion front axles, such as the custom Ford unit in the front of my Jeep. Also, while the ring gear does a lot of slinging, the carrier is also spinning and throwing the goo.

Regarding pinion lube, if you could draw a line from the fill plug straight back, the pinion would likely be partially submerged in gear oil as well, on a low pinion axle.
I just checked the Sterling in my truck and the Fill plug is quite a bit higher than the pinion centerline.

 

[CarbonSteel]

Originally Posted by Zaedock
There are channels cast in to the housing that help channel gear oil to the pinion bearings (primarily the outer). These channels are especially important in High Pinion front axles, such as the custom Ford unit in the front of my Jeep. Also, while the ring gear does a lot of slinging, the carrier is also spinning and throwing the goo.

Regarding pinion lube, if you could draw a line from the fill plug straight back, the pinion would likely be partially submerged in gear oil as well, on a low pinion axle.
I just checked the Sterling in my truck and the Fill plug is quite a bit higher than the pinion centerline.




This is a good idea, I will check mine. I have been reading quite a bit about low pinion vs. high pinion. In the end, the oil may actually be capable of being slung onto the temperature probe but with the front axle disconnect I will not be able to see that until I'm off road.

 

[ABN_CBT_ENGR]

Originally Posted by 2015_PSD
Ah--that is what I thought and now that I am about to install the "permanent" axle covers, I may need to rethink the temperature sensor probe location for the front axle. I am not sure enough oil will be slung towards the upper part of the axle cover to capture a reading, but then again, I need to spend some time off road in 4x4 mode to see since it has a front axle disconnect which prevents the axles and drive shaft from turning in 4x2 so the oil is not moving anyway.

Thanks guys!


If I may, what exactly are you wanting to accomplish or measure and then to what purpose?

Might be able to assist if I understood better. I have designed many gear drives and installed all kinds of sensors- depends on what the metric is that determines what sensor and where it needs to go

 

[CarbonSteel]

Originally Posted by ABN_CBT_ENGR
Originally Posted by 2015_PSD
Ah--that is what I thought and now that I am about to install the "permanent" axle covers, I may need to rethink the temperature sensor probe location for the front axle. I am not sure enough oil will be slung towards the upper part of the axle cover to capture a reading, but then again, I need to spend some time off road in 4x4 mode to see since it has a front axle disconnect which prevents the axles and drive shaft from turning in 4x2 so the oil is not moving anyway.

Thanks guys!


If I may, what exactly are you wanting to accomplish or measure and then to what purpose?

Might be able to assist if I understood better. I have designed many gear drives and installed all kinds of sensors- depends on what the metric is that determines what sensor and where it needs to go

Axle fluid temperatures; the rear works fine, but the front has not posted any numbers yet. However, that was expected, because the FAD disconnects the driveshaft and axles so there is no fluid moving.

I wanted to confirm which way the ring gear rotates so in the event after I do a 4x4 drive off-road for several hours I do not have a reading then is due to the path oil takes and I will need to consider a different location for the sensor.

 

[Fattylocks]

Originally Posted by 2015_PSD
Ah--that is what I thought and now that I am about to install the "permanent" axle covers, I may need to rethink the temperature sensor probe location for the front axle. I am not sure enough oil will be slung towards the upper part of the axle cover to capture a reading, but then again, I need to spend some time off road in 4x4 mode to see since it has a front axle disconnect which prevents the axles and drive shaft from turning in 4x2 so the oil is not moving anyway.

Thanks guys!

Sounds like a plan. Let's go!