Front bearing lubrication

[saflyer]

On the advice of some on one of the forums i use I changed my front wheel hub grease fittings to the type in the picture. I don’t know what they are called so if anyone can help me with that please do.

I was given the briefest insulation on checking and replenishing the fluid and have now forgotten what little I knew. Can anyone tell me how to check the level and fill if necessary and with what type of lubricant?

Ed         
‘05 HR Ambassador 

 

Edited September 5, 2023 by saflyer
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[cowpoke]

If you look on the clear plastic part by the red knob you will see a line that says “full”. If below that line add 80-90 oil and bring it up to that line

[Tom Wallis]

To add oil you would pull out the blue plug and squirt some in the hole. The one in the picture is fine though. The oil should come up to just below the hole. Any suitable gear lube should be fine. You really don't need to worry about changing it for a long time.

[cowpoke]

Sorry— I should have said blue plug— all mine are red

[Paul Busch]

I have been helping a trucking company owner and major truck repair shop with remodeling his offices and I have those on my tag axil and considered putting them on the rear axil and they are taking them off their trucks and trailers because of failure. I am sure it is because of high mileage and excessive weight but I thought that was interesting. I just keep an eye on mine and Tom is correct.

[hex_nut]

Paul

You would NOT put these on the rear axle as the rear axle is already liquid oil lubricated from the differential.  If your front wheel bearings (or tag axle) are lubricated with thick wheel bearing grease, converting to liquid oil lubrication is a maintenance convenience.  The trucking companies are probably reverting to using wheel bearing grease because their drivers never check the oil level in the liquid filled hubs. 

Richard

[Paul Busch]

Richard,

thanks. They are on my tag and I was interested in getting them for my front wheels but opted to leave them as grease fitting.

[hex_nut]

Paul

I left my front hubs with wheel bearing grease for many years until it became time to service them.  Since I had to service them anyway (a task that I do not enjoy), I chose to convert them to liquid filled.  As long as I have no seal failures, I will never have to service them again.

Richard

[K9 Exec]

Hi Ed, good advice on the forum- you won't go wrong. 🙂

I will add this to the post: I would use full synthetic (any brand) 75w90 gear oil and call it a day. I have a friend in the lubrication analysis business that I trust and have seen the data. Pop the cap, add the oil to the add/full line right below the lip, replace the cap and you are good. You will be good until you have to add it again, which unless you have a leak should be never. Drain then refill  every 300,000-500,000 miles for commercial use or 3-5 years. I would not use dino in this application due to high heat and breakdown, the synthetic is the same cost so it is a win-win. You can buy a quart bottle with the cut top and will be good for both sides typically with a bit to spare. 🙂

Best of luck!

[planodp]

@saflyer I was thinking of converting my front hubs to oil. Can you post what part it take to convert it? Thanks

[diplomat don]

20 hours ago, K9 Exec said:

Hi Ed, good advice on the forum- you won't go wrong. 🙂

I will add this to the post: I would use full synthetic (any brand) 75w90 gear oil and call it a day. I have a friend in the lubrication analysis business that I trust and have seen the data. Pop the cap, add the oil to the add/full line right below the lip, replace the cap and you are good. You will be good until you have to add it again, which unless you have a leak should be never. Drain then refill  every 300,000-500,000 miles for commercial use or 3-5 years. I would not use dino in this application due to high heat and breakdown, the synthetic is the same cost so it is a win-win. You can buy a quart bottle with the cut top and will be good for both sides typically with a bit to spare. 🙂

Best of luck!

If you experience high heat and breakdown of the gear oil your bearings are too tight. Wheel bearings should never be more than warm to the touch. 43 years and 4 million miles experience. 

[Lakesidelogger]

Hi guys,

Please be reminded that if you have “top up” the fluid it means you have a leaking wheel seal which could be contaminating the brakes. (Unless it’s leaking to the outside which would be quite obvious.) Gear oil doesn’t evaporate.

Monaco service interval for steer axle bearings (grease) is 50,000 miles, so once you service them you can basically forget about it for a few years in most cases.

Just my 2 cents.

[Paul J A]

I ran 108K 10 years full timing. Grease the front every 50K. Never a problem. 

[saflyer]

On 9/5/2023 at 1:23 PM, K9 Exec said:

Hi Ed, good advice on the forum- you won't go wrong. 🙂

I will add this to the post: I would use full synthetic (any brand) 75w90 gear oil and call it a day. I have a friend in the lubrication analysis business that I trust and have seen the data. Pop the cap, add the oil to the add/full line right below the lip, replace the cap and you are good. You will be good until you have to add it again, which unless you have a leak should be never. Drain then refill  every 300,000-500,000 miles for commercial use or 3-5 years. I would not use dino in this application due to high heat and breakdown, the synthetic is the same cost so it is a win-win. You can buy a quart bottle with the cut top and will be good for both sides typically with a bit to spare. 🙂

Best of luck!

I have no idea what lube they were originally filled with. When I need to add lube can I mix the synthetic with whatever is in it now or should I drain and start over.

[Ivan K]

You can just add if you have to but that would mean that you have a leak (unless it was low from the get go) and you don't want it to leak at the back on brakes, if it did. Personally, if I did not trust that they used full synthetic, I would drain them and refill. It doesn't look like yours have a drain plug so you would have to suck it out. Tilting the axle helps as there is oil behind the outer bearing. I use the same synthetic gear oil as for the differential for simplicity. Once you refill, check again in a bit because it will take some time to level out.

[saflyer]

11 minutes ago, Ivan K said:

You can just add if you have to but that would mean that you have a leak (unless it was low from the get go) and you don't want it to leak at the back on brakes, if it did. Personally, if I did not trust that they used full synthetic, I would drain them and refill. It doesn't look like yours have a drain plug so you would have to suck it out. Tilting the axle helps as there is oil behind the outer bearing. I use the same synthetic gear oil as for the differential for simplicity. Once you refill, check again in a bit because it will take some time to level out.

Thanks