Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 13, 2025 ...

Hub oil level

March 21, 2012, 10:06:23 pm

When Brett inspected our coach he advised that I check the hub oil level on the front wheels.  I had not done this in the past.  Sure enough, one was low and adding additional hub oil (Lucus) did not help.... the level soon dropped after a few miles of driving.  The inside surface of the wheel assembly showed a lot of oil.  The seal was gone in spite of the fact that I had FOT replace that seal the year before.  Got the seal replaced here in Tucson at the Freightliner dealer ($400).  I asked about the short life of the FOT seal and the Freightliner service guy said that this often happens when coaches sit for long periods.  If long periods means months....guilty. 

Checking the hub oil level is very easy.  Remove the hub cap and inspect the level of oil in the clear plastic window.  Barry has a page on his website on this topic. 


Inspect Steer Axle Hub Oil

Lucus has a hub oil that is available at many truck stops.

Lucas Hub Oil : Lucas Oil

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Re: Hub oil level

Reply #1 – March 21, 2012, 10:47:30 pm

George,

Glad you caught it.  Having all the oil drain out and a front wheel bearing seize up at 60 MPH can be an eye opening (or closing) experience.

Wonder if the bearing end play was properly set???

Sounds like you are continuing to whittle away at the list.

Brett

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Re: Hub oil level

Reply #2 – March 21, 2012, 11:02:25 pm

I would check the riding surface of the seal. It may be scored, in which case it would have to be sleeved. When my seal failed the mechanic said he had a choice of seal kits, with and without sleeves.

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Re: Hub oil level

Reply #3 – March 22, 2012, 12:18:52 am

We drilled a 2" hole in center of hub cap and check hub oil level when we check engine oil, coolant, hydraulic & generator oil levels.

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Re: Hub oil level

Reply #4 – March 22, 2012, 06:28:02 am

I had to have my front wheel seals replaced about 3 years ago after purchase (discovered on the way home).  One was done at a tire dealer in Charleston, WV and the other one at a truck shop in Austin, TX.  Have not had a problem since.  If the oil is low, it is almost a sure bet the seal is leaking.  When I found the oil was low, not knowing any better, added oil and soon the brake pads for that wheel were lubed too.  Some oil did remain in the hub so the bearings were not damaged.  Cost at both locations was about $200 per wheel.  The sleeve was replaced each time as it was part of the seal kit.  The sleeve looks like it is part of the axle when installed.  Until I bought a Foretravel, I thought front (non-drive) wheel bearings were greased.  If one is leaking might as well get the other one done too, as it may soon be leaking.  That was my experience anyway. 

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Re: Hub oil level

Reply #5 – March 22, 2012, 10:09:27 am

Jerry,

The vast majority of DP's as well as OTR trucks have oil bath front wheel bearings, not grease. 

Brett

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Re: Hub oil level

Reply #6 – March 22, 2012, 10:12:20 am

What should the oil level be on the site window. If low and no oil splash showing on inside of wheel, what now

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Re: Hub oil level

Reply #7 – March 22, 2012, 10:32:33 am

Bill,

There is a ring and an arrow labeled OIL LEVEL on the clear plastic. 

And oil can leak to the outside (where it would show on the wheel) or to the inside where it would not be readily visible.

Low oil level can also be from someone filling to the correct level and immediately installing the plug.  It takes a few minutes for the oil to migrate "across" the hub and seek its correct level.

Also, you must be on a level surface left/right to get an accurate reading.

Brett

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Re: Hub oil level

Reply #8 – April 06, 2015, 04:40:44 pm

What weight oil is used?

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Re: Hub oil level

Reply #9 – April 06, 2015, 05:16:14 pm

This is what we use. Mobil Delvac Synthetic Gear Oil 80W-140

Pamela & Mike

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Re: Hub oil level

Reply #10 – April 06, 2015, 07:01:29 pm

Inspect Steer Axle Hub Oil
and, this from Eaton:
Lubrication Requirements
The ability of a drive axle to deliver quiet, trouble-free operation
over a period of years is largely dependent upon the use
of good quality gear lubrication in the correct quantity. The
most satisfactory results can be obtained by following the
directions contained in this manual.
The following lubrication instructions represent the most current
recommendations from the Commercial Vehicle Systems
Division of Dana Corporation.
Approved Lubricants
General - Gear lubrications acceptable under military specification
(MILSPEC) MIL-L-2105D (Lubricating Oils, Gear, Multipurpose)
are approved for use in Dana Drive Axles. The
MIL-L-2105D specification defines performance and viscosity
requirements for multigrade oils. It supersedes both
MIL-L-2105B, MIL-L-2105C and cold weather specification
MIL-L-10324A. This specification applies to both petroleumbased
and synthetic based gear lubricants if they appear on
the most current "Qualified Products List" (QPL-2105) for
MIL-L-2105D.
Note: The use of separate oil additives and/or friction modifiers
are not approved in Dana Drive Axles.
Synthetic based - Synthetic-based gear lubricants exhibit
superior thermal and oxidation stability, and generally
degrade at a lower rate when compared to petroleum-based
lubricants. The performance characteristics of these lubricants
include extended change intervals, improved fuel economy,
better extreme temperature operation, reduced wear and
cleaner component appearance. The family of Dana
Roadrangerª gear lubricants represents a premium quality
synthetic lube which fully meets or exceeds the requirements
of MIL-L-2105E. These products, available in both 75W-90
and 80/W-140, have demonstrated superior performance in
comparison to others qualified under the MILSPEC, as demonstrated
by extensive laboratory and field testing. For a complete
list of Roadranger¨ approved synthetic lubricants
contact your local Dana representative. See back cover of this
manual for appropriate phone number.
Makeup lube of different brands and manufacturers is not
recommended.

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