I have had a little issue with my right front wheel bearing. The 90 weight oil was a weird tannish color. I used a large syringe and a bit of tubing to suck the oil out and replaced with fresh 90 weight oil. I did not feel comfortable going down the road so had it looked at by Forrest Tire in Carlsbad NM this AM. They removed the wheel and the outer seal and completely drained out the oil. Tech told me everything looked OK to him and that it looked as if some water got in there with the oil. Left side was checked and was fine. Guess that's something else I will have to keep my eyes on. Folks did not charge me anything for checking everything out and putting it all back together with an oil refill, although I did tip the tech. Any one ever had water intrusion in that area.
Roland
I did install new Stemco Hub Seals on both sides in case that was the cause of the water intrusion.
Roland
I sure did - 3 years ago. Only on one side. Has not happened again. See photos of oil: front wheel stemco oil reservoir (http://www.foreforums.com/index.php?topic=18468.msg126933#msg126933)
Replacing the hole plugs on the cover is a biggie, the other is to use Lucus Hub Oil instead of 90 wt.
That is exactly what my oil looked like.
Roland
I have seen that before and have cured it by drilling 4 small holes 90 degrees apart in the edge of the hubcap to keep the water from building up enough to enter through the Stemco plug
Lucas hub oil is what I had in my hubs. Forrest Tire used 90 wt oil which I will replace.
Roland
The neoprene seals are mainly made to keep the oil in. When the hub is warm and you splash water up it cools and creates a vacuum and will suck the water in. If using the seal that is stationary on the hub and spindle it has metal rings that do the sealing internally and they don't have that problem.
My x Foretravel chassis guru said that to do the front wheel oil correctly that the hubs had to pulled as the oil pooled in the lower hub and was not drainable and not mixable with synthetic.
So we waited to replace the seals to change to synthetic oil and pretension the wheel bearings a bit to lessen the chance of wander.
Bob,
In a perfect world, I agree that it would be nice to remove 100% of the old oil.
But, you can get 95% of the same thing with a LOT less labor:
Siphon out/suck out as much oil as you can (just removing hub cap center and center rubber plug).
Overfill with new oil. Let sit for an hour or so.
Siphon out/suck out and refill to full mark.
Repeat next time it is convenient.
Whole process takes 15 minutes to do both front wheels. In most cases one quart will do the whole job.
Exactly the alternate method he mentioned.
Not sure why he disliked mixing the different oils so much. He was normally a flat rate quick mechanic.
Any engineering reason that overriding on mixing them?
While on the subject of front wheel bearings..... I plan on replacing the front wheel seals next week. The owners manual specifies 85-140 gear oil, I noticed in this thread that only 90 wt or Lucas Hub oil was mentioned. I used the 85-140wt in the rear axle last week (4gal) and plan on using some of the remaining portion in the front. Any good reason to switch?
Also, what is the recommended torque on the bearing retaining or axle nut?
I have always torqued trailer axle nuts to 100 lbs and then backed off to the first slot in the castle nut to align the cotter pin.
There is no spec for the wheel bearing nut. Instead, there is a free-play spec (.002- .005" if I remember, but look it up for your axle). You will need a dial indicator to set it accurately.
Yes, I know that some of the old timers can do this by feel, but even at Foretravel where there are some who have been around a LONG time, they use a dial indicator.
As far as oil viscosity, again look it up for your axle (most have this info available on-line). The axle maker, PN and serial number are on a small metal tag, front middle of the front axle.
The legalities is to use a dial indicator. Verifiable in a court case according to the DOT and the stemco seal installation video I watched. You could see him grimace as he mentioned the legality twice during the 30 minute video
Thst being said a slight preload reduces the steering wander. Not quantifiable. Not legally defensible.
So a good experienced diesel motorhome chassis tech would preload the bearing a bit without anyone watching as his training and experience showed him that this old time adjustment stopped the steering wander the customer complained about every time.
No damage, no heating. No wander.
Noticed the new Michelin xza-3+ evertreads mention of self steering sipes in the tires design? For the first 50% of the tread?
My opinion is that tire design helps compensate for the steering wander created by having .002-.005 play in the brake rotor.
My unicoach was at .003 and had a dead spot and a slight wander. My x Foretravel chassis guru laughed and fixed mine.
I asked Vincent how many coaches he had done and his answer was hundreds of all brands. With 100% results.
At a preload the wander went away and with the xza-3's the coach goes straight in a light crosswind and only requires slight tension against the steering wheels edge every so often to keep it straight.
I did and do do a heat gun walk around at every stop to verify any issues with bearings or sticking rotors. Nothing.
If I ran Foretravel I would require use of the dial indicator also. Legally defense able.
I would think the less expensive line haul steer tires without the self steering design features that the Michelin's have would benefit from a preloaded wheel bearing setup.
Mine did. Xza-1's I do not think had the level of self correcting technology the xza-3's do.
Just my two cents and thirty years of selling, driving and fixing customers diesel pusher motorhomes.
I made more money if the customer could drive their rig from the bottom of the steering wheel everytime.
Self interest to fix handling issues.
We use the same oil in rear axle and front hubs: Synthetic 75/140 or similar viscosity.
FYI
On the Stemco Hub cap, in the very middle of the rubber plug, there will be a tiny little hole. You will not see it, but trust me, it is there.
The reason for the hole is that it is a vent to relive the pressure that will build up as the wheel is used and gets warm, difference in climate, atmospheric pressure differences from sea level to mountain tops, well you get the picture.
With out the vent, you could get an over pressure in the hub that would cause the plug to blow out or cause the wheel seal to leak.
If you use a pressure washer, or get a little aggressive with a hose while washing, you can very easily cause water to enter into the hub. I probably have to change at least one hub oil a week because of a driver washing his truck with a pressure washer. Worst case scenario is that he blows the plug right out of the hub and fills it right up with water.
When I change hub oils, I do it 3 times over about a weeks time. I change it the first and second nights and some time during the next 4 to 5 days I will do it again. In the case of a very badly contaminated hub with lots of water emulsified with the oil, this is when it looks like that nasty grey milkshake looking stuff, then the only way to get it nice and clean is the hub comes off, the seal and bearings come out, everything is solvent washed and dried, inspected and reassembled with a new seal and clean oil.
On a motorhome application where the unit will tend to stay in one spot for weeks at a time, I would be tempted to change the oil several times or have the hub taken apart and properly cleaned.
Water is a bearings enemy. It doesn't take long for a little left over water in the oil to start causing a problem with a bearing, and if the bearing is not moving, like when at rest in an RV park, the damage can occur.
Also the red plug will shrink over time, if you can wiggle it change it.