Surplus oil in a single portal axle

D

djordanbuilders

New member
Sep 5, 2024
9
0
1
Greetings to everybody, have a pleasant day!
Indeed, it is a persistent problem... However, I have consistently seen information on the transfer between the hub reduction (portal axle) and the differential; might the reverse occur?
I have recently inspected and replaced the hub reduction oil on my U1650 for the first time. In three instances, it was ideal: precisely at the filler screw, with a volume of around 600 ml.
However, at the left rear, there was almost double! over one liter.
How could the previous owner have erroneously introduced such a substantial amount via the filler hole? It is unfeasible without its emergence. Is it feasible to fill from an other opening?
Could you provide any suggestions or share similar experiences?

Thank you and enjoy the mud!
 
Indeed...
Overfilling from the apertures in the hub housing is very challenging.
There exists a primary aperture, a 'nearly primary aperture,' and a drainage system.

If an owner really want to overfill the portal, removing the vent tube and adding more lubricant from the top may be feasible.

If the owner has issues with that hub consistently registering low oil levels, then overfilling it via the vent might perhaps serve as a partial remedy.

I am uncertain about its efficacy, since surplus oil may be prone to migrating upwards and escaping via the vent.

Although it is possible to overfill via the vent, it seems to be an improbable occurrence. Improbable, but feasible.

It is probable that oil from the differential is seeping into the gateway.

I would empty the gateway and refill it to the appropriate level.
Subsequently, replenish the differential oil as well.

Subsequently, operate the vehicle and observe the oil level in the portal.

If it gets overfilled again, there is only one source it can originate from.
 
Have you checked the oil level in the differential? It is not unusual to get a transfer from the differential if the axle seal is compromised.
 
I concur that the substance is likely oil from the differential; but, one may easily overfill a portal if they lack the knowledge or purpose to fill it correctly.

When overfilling a portal, one essentially pressurizes the portal and seals it before releasing the surplus. The fill hole is positioned below the fluid level and is sufficiently tiny, causing the viscous gear oil to flow inadequately, allowing for effective capping before a substantial portion escapes. The aforementioned task requires the removal of a single fill plug.

Alternatively, you will extract both fill plugs and use the slightly lower one as your oil level gauge while refilling via the slightly higher one. Cease filling with the first indication of oil flow from the indicator side and seal both openings to achieve optimal filling.
 
I concur with the single hole overfill procedure.

Augustin said that it contained about double the usual quantity in the gateway.

It would likely be rather challenging to get that volume in a single port unless one devised a fitting with a hose and a large syringe, therefore pushing the oil in while the port was effectively sealed.
 
I used a pressurized fill bottle to exceed the capacity of mine. It resembles a garden weed sprayer; one fills it with liquid and pumps it to create pressure. It has fittings that accommodate different orifices, with a tap to control the flow. It effectively filled those gateways to capacity and beyond. Reinsert the fill bolt before the fluid completely runs out.
 
The oil seal may really be the issue, since it is subject to wear over time.
The 747 axles have a vent tube that connects the portal chamber to the axle tube. In my situation, the sealant used to secure the tube had solidified and fissured, resulting in oil leakage beyond the tube and inundating the portal with surplus oil. This topic has been addressed in prior discussions.
There are at least two potential explanations, excluding the possibility of the owner overfilling.
 
There are two pathways for the oil to infiltrate the portal box, but only one origin, correct? Is it the differential?

If the vent tube is integral to the portal venting system, then portal oil ascending the vent and seeping back into the portal box constitutes a closed system, hence preventing a rise in the oil level inside the box. It may diminish somewhat.

However, if oil is escaping from the differential due to a defective seal, it is route No. 1.

Does the second way go past the same leaking seal and then navigate through the fractured putty around the vent tube (external to the tube, not internal)? Subsequently, into the box?
Seeking to comprehend the routes.

I do not believe that oil could flow down the outside of the vent tube and enter the portal box. A brief rigid line is followed by a rubber hose.
 
You must log in or register to reply here.
Top Bottom