Mobil Polyrex EP-2 for trailer wheel bearings - Good or not good?

[Ramguy3500]

This is my first post on this forum, but I've been reading here quite a bit lately. Please bear with me. I actually posted this first in the wrong forum. Just moved it here.

I was led here when researching a solution to a problem I didn't really have. I had seen Lucas Xtra Heavy Duty green grease, and because I use the trailer daily, I decided I "needed" a better grease for my trailer wheel bearings than the Lucas RNT I had been using.

20 Foot deckover bumper pull
2 7K Dexter "EZ Lube" axles
14k GVWR
Trailer weight 3,350 lbs
Max Load Capacity 10,650

I use the trailer for work and tow with it every day delivering 2k lb pallets of bottled water to warehouses and construction sites. I usually start the day with 5 pallets, deliver them, and reload a couple times per day, so 2k to 10K at any given point. I live in Houston and deliver around the greater Houston area. I put around 1000 miles per week on it.

After seeing Lucas Heavy Duty green grease, I started researching it's compatibility with RNT, and/or red lithium greases in general, as I use that and didn't really want to mix the 2, even if they were compatible. That research led me to this forum, where I've searched and read numerous different threads regarding polyurea based grease, sheer stable vs conventional, etc. I learned the Lucas Xtra Heavy Duty is Polyurea conventional and not compatible with really any other types of grease. So that one was out. I found different types of Poly sheer stable, and I decided to go with the Mobil Polyrex EP-2.

I chose the Mobil Polyrex EP-2 because, as found on their website, " its outstanding high-temperature oxidation stability, load-carrying capability, shear stability, water resistance and wide operating temperature range, Mobil Polyrex EP 2 is an excellent multi-purpose grease for a wide array of industrial and construction applications." It's also NLGI 2, so I figured I was on the right track.

Two weeks ago it was time for the 12k mile bearing packing (I've educated myself on the EZ Lube system and prefer packing and inspecting every 12k), so I bought new races and bearings, pulled all the hubs, removed all old grease, cleaned old grease out of hubs with brake cleaner, and packed the new bearings with Mobil Polyrex EP-2. I even used it as a good excuse to buy one of the fancy Lock-N-Lube guns and couplers!

I expected the hubs to be running cooler than before, but they are just as hot to the touch some days as before. They're not hot, hot, but warmer than I'd like. I realize there are other factors at play there, and I will make sure castle nut is not too tight. I'm also going to get an temp gun to monitor it more precisely.

In the meantime, I am looking for all types of feedback, criticism, questioning, etc on my decision. I started searching around online, and I can't find anyone who says they use this particular grease on their trailer wheel bearings. Some use Polyurea based by John Deere and Kubota, but nobody seems to use Mobil Polyrex EP-2. I feel like I must be missing something!

Mobil Polyrex EP 2
Thickener Type - Polyurea
NLGI Grade - 2
Color - Green
Base Oil Viscosity, ASTM D - 445
cSt @ 40°C - 235
cSt @ 100°C - 18.4
Mineral Oil Viscosity Index, ASTM D 2270 - 85
Penetration, ASTM D217 worked, 60x, mm/10 - 280
Penetration, ASTM D217 worked, 100,000, mm/10 - 310
Dropping Point, ASTM D 2265, °C (°F) - 280 (535)
High Temperature Grease Life, ASTM D 3336, Hours @ 177°C - 490
4-Ball Weld, ASTM D 2596, kg - 500
4-Ball Wear Scar Diameter, @1200 rpm, 40kg, 75°C, 1 Hour, mm - 0.4
Timken OK Load, ASTM D 2509, lb - 45
Low Temperature Torque, ASTM D 4693, -40°C, Nm - 12.2
Low Temperature Torque, ASTM D 1478, Torque @ Startup/1 Hour in gcm and -20Cº - 1600/180
Oil separation test, ASTM D 1742, % - ‹0.3
Water Spray-off, ASTM D 4049, % - 15
Water Washout, ASTM D 1264, @ 79°C, % - 2.7
Rust Protection, ASTM D 1743 - Pass

 

[midobo]

Is the heat from the trailer brakes?

 

[greaseguy15]

Good on you for being proactive with your maintenance practices!

Next time you’re due for a repack I’d recommend using a grease that meets the NLGI GC-LB specification. This is specifically for wheel bearing grease. The Mobil product is certainly stout but may be more designed for industrial and off highway applications compared to wheel bearings. Here’s a link to all the approved products:

https://www.nlgi.org/certifications/product/certified-products/?fl=a

A wide number of them should be readily available in the Houston market through reputable suppliers.

This is the manual for the Dexter hubs, it looks like you followed the rebuild procedure correctly. It also has a list of recommended greases on page 52:

https://www.dextergroup.com/user_area/content_media/raw/LDServiceOnline.pdf

As for the temps not coming down unfortunately just a hand test isn’t conclusive whether they were running cooler or not. I’d check with a temp gun if you have one. If you’re not seeing wear at your next 12k check I’d say you’re probably fine and don’t need to worry about your axle temps. If you want to do more work still you could look at changing the hubs over to oil lubrication which should lower temps as oil transfers heat better then grease.

 

[CDX825]

I switched to poyurea grease for wheel bearings a few years ago. I use it for wheel bearings in vehicles and trailers. The service life of the bearing has been greatly extended from using it.

 

[facility1]

Schaeffer's #274 or #219 NLGI 2 would work fine in your app, its also Aluminum complex for better water resistance. or if you want to try something else, Valvoline cobalt looks like some interesting stuff to., check on this grease site page for info.

 

[willbur]

This is my first post on this forum, but I've been reading here quite a bit lately. Please bear with me. I actually posted this first in the wrong forum. Just moved it here.

I was led here when researching a solution to a problem I didn't really have. I had seen Lucas Xtra Heavy Duty green grease, and because I use the trailer daily, I decided I "needed" a better grease for my trailer wheel bearings than the Lucas RNT I had been using.

20 Foot deckover bumper pull
2 7K Dexter "EZ Lube" axles
14k GVWR
Trailer weight 3,350 lbs
Max Load Capacity 10,650

I use the trailer for work and tow with it every day delivering 2k lb pallets of bottled water to warehouses and construction sites. I usually start the day with 5 pallets, deliver them, and reload a couple times per day, so 2k to 10K at any given point. I live in Houston and deliver around the greater Houston area. I put around 1000 miles per week on it.

After seeing Lucas Heavy Duty green grease, I started researching it's compatibility with RNT, and/or red lithium greases in general, as I use that and didn't really want to mix the 2, even if they were compatible. That research led me to this forum, where I've searched and read numerous different threads regarding polyurea based grease, sheer stable vs conventional, etc. I learned the Lucas Xtra Heavy Duty is Polyurea conventional and not compatible with really any other types of grease. So that one was out. I found different types of Poly sheer stable, and I decided to go with the Mobil Polyrex EP-2.

I chose the Mobil Polyrex EP-2 because, as found on their website, " its outstanding high-temperature oxidation stability, load-carrying capability, shear stability, water resistance and wide operating temperature range, Mobil Polyrex EP 2 is an excellent multi-purpose grease for a wide array of industrial and construction applications." It's also NLGI 2, so I figured I was on the right track.

Two weeks ago it was time for the 12k mile bearing packing (I've educated myself on the EZ Lube system and prefer packing and inspecting every 12k), so I bought new races and bearings, pulled all the hubs, removed all old grease, cleaned old grease out of hubs with brake cleaner, and packed the new bearings with Mobil Polyrex EP-2. I even used it as a good excuse to buy one of the fancy Lock-N-Lube guns and couplers!

I expected the hubs to be running cooler than before, but they are just as hot to the touch some days as before. They're not hot, hot, but warmer than I'd like. I realize there are other factors at play there, and I will make sure castle nut is not too tight. I'm also going to get an temp gun to monitor it more precisely.

In the meantime, I am looking for all types of feedback, criticism, questioning, etc on my decision. I started searching around online, and I can't find anyone who says they use this particular grease on their trailer wheel bearings. Some use Polyurea based by John Deere and Kubota, but nobody seems to use Mobil Polyrex EP-2. I feel like I must be missing something!

Temp gun is a good idea. I use one, too. Be sure the bearings are adjusted correctly

 

[facility1]

make sure your tires are properly inflated, low or over loaded tires can also run warm/hot may contribute to the heating ,,,good point to have correct bearing tension or pre-load, check brakes for dragging , bearings do often just run hot under a continuous load can be normal, temp gun is also a good idea too. too much grease in bearing cavity (over packed) can run higher temps due to friction on itself, look for grease being forced out around seals .