Wheel Bearing Grease Question

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TheSpencerJM
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Wheel Bearing Grease Question

Hi,

 

I'm repacking hte bearings in my 1984 Scamp Trailer for the first time and am wondering if any automotive wheel bearing grease will work? I picked up a tube of MasterPro Chemicals High-Temp Wheel Bearing Grease from Oreilly's which is a lithium base grease, but starting to wonder if I should get one of the more expensive greases meant specifically for a trailer. Your thoughts?

 

https://www.oreillyauto.com/detail/b/masterpro-chemicals-4340/chemicals-...

Thanks!

 

Spencer 

 

Lmitc210
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Check out this post

Spencer, check out JTST_Scamper's post from last Oct. "Lippert Axle Super Lube." I would think any mulit-purpose lithium-based EP NLGI-2 would do. We picked up our 2016 Scamp 13 Deluxe in early March, and as a new owner I'll be removing, cleaning, and inspecting my bearings next weekend, and plan on re-packing using some Valvoline multi-purpose EP NLGI-2 grease that I've used in the past for car and truck wheel bearings.

2016 13 Scamp Deluxe
TV: 2020 Subaru Ascent Premium
Minnesota

Bob B88
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Blow out the bearing back seal ??

I checked out the post from last Oct. The letter from Lippert says,

"You would slow add grease until it comes out the front cup. I would just be careful doing this as you do not want to blow out the back seal."

What do they mean "be careful doing this", what would you have to do to blow out the back seal with a manual grease gun? We just bought a 2016 13' Scamp and I don't want to break it right off. Anyone with hints on how to replace the grease without getting into problems (like blowing out the back seal)? Did anyone ever blow it out?

ELongest
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EZ Lube

When adding grease to a EZ lube axle the trailer should be jacked up and you spin the wheel when pumping in grease into the fitting. A grease gun can generate several thousand pounds of pressure. See attached article.

Eddie

https://www.machinerylubrication.com/Read/28803/grease-gun-pressure

Gordon2
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IMHO, the best way to make

IMHO, the best way to make sure you dont have a accident with the EZ Lube is to pull the hub, remove, clean, and inspect the bearings, then repack and reinstall.  In other words the traditional method. You do not have to use the EZ Lube.

As for grease .. my axle manual lists some brands and types that are compatible and recommended to use with what was original in my new axle.  So I went with one of those.  Otherwise we should talk about the base material and which are safe to use with each other.

Lmitc210
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I'm inclined to agree with

I'm inclined to agree with Gordon2. All the literature, videos, etc. for the SuperLube/EZLube grease systems tell you to "be careful" to not add too much grease or you'll blow out the rear grease seal, which is not good (can introduce grease onto the brake shoes); 1-2 pumps of grease is the maximum they recommend. My question with that approach is, besides just going with the 1-2 pumps of grease and assuming that's good, how can you "be careful" when you can't really see what's going on with the inner seal? How often do you add the 1-2 pumps? In my opinion, there's no substitute for an annual drum pull-off and bearing cleaning/inspection then a re-pack. But, I'll admit that's a chore that some might not want to take on. I find it therapeutic!

Regarding grease, I also agree that most general wheel bearing grease should be fine, but I noticed that Lippert and Dexter's specifications call for a grease with a higher "drop point" temperature (500 degrees F), so I guess that might be what defines a "high-temperature" grease? Looking at various automotive greases at my local automotive store, some had drop points of 500 degrees F whereas other greases had lower drop points. I used a Valvoline grease that had all the recommended traits: Lithium complex, EP (Extreme Pressure), 500+ drop point, NLGI #2. Pretty much the same price as other middle-line greases.

2016 13 Scamp Deluxe
TV: 2020 Subaru Ascent Premium
Minnesota

Bob B88
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Lubricating the Scamp Superlube Hub

Hey, thanks for the replies. Thanks Eddie for the link about grease gun pressure..the message is 'slow and steady' when pumping grease into the hub.

So I did more digging about the Superlube concept and 'blowing the back seal' comment. Here's a video by Lippert showing their procedure.

https://www.youtube.com/watch?v=s34pBejcQn0

In the video, the guy pumped the grease gun 10 or 12 times until the grease starts to 'seep from the fitting'. 'Seep from the fitting' is a little confusing since the only fitting they talked about was the grease fitting where the grease is pumped in. The grease actually comes out of the outer bearings at the inner circumference of the grease cap and fills the grease cap.

Here's the Lippert instructions on Superlube,

https://www.lci1.com/assets/content/support/sheets/TI___213_Procedure_For_Lubricating_The_Superlube_Hub.pdf

This is the same instructions as in the video, where the grease 'seeps from the fitting', and the fitting is labeled in the diagram as the grease fitting where the grease is pumped in. Confusing.. What happens is, the grease is pumped in through the fitting and travels though the axle spindle and up though another hole (not shown in the diagram) to the space between the inner bearing and the spindle seal. The grease flows against the seal through the inner bearings into the space between the spindle and the hub. This is why you  turn the wheel when you pump, so the grease gets evenly distributed in the bearings. The grease then travels along the spindle and through the outer bearing,then exits around the washer and around the spindle nut into the grease cap. By pumping new grease through the fitting, you can force the old grease out of the hub and bearings, replacing the old grease with the new grease.

Note there's no mention of 'being careful' of blowing out the back seal. I think what people mean by 'be careful' is - don't use an automatic grease gun or a large industrial gun which might apply to much pressure.

So I gave it a test on my 13 ft Scamp after jacking up the frame so the wheel spun freely. I removed the grease cap so I could get a better idea of what was happening. I gave the grease gun about 20 - 30 pumps before the grease came out between the hub and the washer and flowed onto the spindle nut. I always turned the wheel one or two time between pumps.

The next thing I did was to remove the hub from the spindle to see if there was any damage to the back seal (see if the seal was 'blown'). I didn't see anything wrong - the seal looked good. The hub was full of grease as expected. So I replaced the seal per the Lippert instructions ("if the hubs are separated from the axle assembly, the seals MUST be replaced prior to lubrication"). Then I reassembled the hub on the axle and gave if 4 or 5 shots of additional grease.

Here's the axle with the cap on, the grease comes out between the inner cap surface and the axle nut.

Here's the axle with the cap off, the grease comes out between the inner surface of the hub and the axle nut.

Here's a picture of the spindle showing the hole where the grease comes out into the rear bearing.

 

So it seems like the Superlube system is a convenient way of lubing the bearings. I can see shooting 10 pumps of grease through the axles periodically while rotating the wheel to keep the grease fresh (Lippert suggested 3 or 4 pumps every 3000 miles, and to make sure you rotate the wheel after each shot of grease). I bought a IR thermometer to record bearing temperature to give an early warning of bearing problems. We'll see how all this works out..

As for the grease types, here's a chart put out by Dexter axles which shows the grease specs,

http://www.easternmarine.com/media/downloads/6929/Bearing_Lubrication_Chart_4-27-11_3_.pdf

Bob

 

Paul O.
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Hi Spencer, any automotive

Hi Spencer, any automotive bearing grease should do. The special greases meant for trailers are probably intended for trailers that might be launching boats, and might offer extra protection from water intrusion. No need for that here. I usually buy cheap or medium price stuff in this kind of situation.

-Paul
2004 Scamp 19 Deluxe,
2021 Tacoma, Double Cab, 6 cyl. 4WD
Colorado

AnthonyRM
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How often?

How often should the bearings be checked. We bought our 13 footer July 2017 and have about 4,000 miles on the camper. I was intending to use the camper this year and inspect and grease the bearings next year if needed. Should the bearings be checked every year? 

Anthony Memoli

Lmitc210
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The Lippert manual I found

The Lippert manual I found online says "Bearing grease should be replaced every 12,000 miles or 12 months." If you're replacing the grease, this means pulling the drums, removing the rear (inner) grease seal, cleaning the drum spindle-hole of all grease, and cleaning and inspecting the bearings and races (or, in other vernacular, cones and cups, respectively). So, the check will, in effect, mean a bearing clean, inspection, repacking and inner seal replacement. You'll also inspect your brake components and adjust your brakes at the same time. So, I think doing this annually is a good thing, ideally prior to the Scamping season.

I'm making it a point to touch the drum tubes every time we stop for gas, lunch, etc. If the tube (what the grease cap fits onto) is very hot to the point where you can't comfortably leave you finger on it for more than a second, that might indicate a bearing problem that would justify in inspection as soon as possible. I've read that heavy braking can also cause over-heating of the drum, but a bad bearing can get hot enough to fuse the race to the spindle or, so I've read, cause a grease/tire fire. I've never experienced that, so no first-hand experience.

2016 13 Scamp Deluxe
TV: 2020 Subaru Ascent Premium
Minnesota