Bearing buddy

[L911]

What size bearing buddies will fit my 73' Ambassador (built in 70').

[Phoenix]

I don't think Bearing Buddies are recommended for anything other than boat trailers. I seem to recall that the pressurized grease will blow the seals out the back side of the bearings and allow dirt, water, etc. to enter the wheel bearing.

The reason they put Bearing Buddies on boat trailers is that when the axle(s) are submerged, the bearings and other parts contract and shrink, which causes a vacuum that draws water into the bearing. The water-contaminated bearing grease then causes the bearing to fail.

Bearing Buddies have a spring and pressure disk with zerk fitting that maintain a slight positive pressure on the bearing grease, which prevents water from entering the bearing when the wheel is submerged during boat launch. If your wheel bearings are never submerged, you don't need Bearing Buddies.

Other problems encountered with Bearing Buddies include:

* Blown rear (wheel bearing) seals.

* Rough roads or tire impacts can knock Bearing Buddies off the axles, leaving the hub and bearing exposed to contamination.

* As wheel bearings heat up, the extra grease expands and leaks out of the Bearing Buddies, slinging globs of grease all over your wheels and the side of your travel trailer (or boat). If you grease your own wheel bearings, you can imagine what a mess this makes, smeared all over your Airstream.

So, unless you regularly back your Airstream far enough down boat ramps or the shoreline to where your wheel bearings are submerged, you don't need (or want) Bearing Buddies.

Just an opinion.

Enough of the "cons"; now, for the "pros"...

[dwightdi]

The bearing grease seals on Airstream trailers are not designed to hold the pressure that Bearing Buddies are likely to generate. Therefore the grease will leak out inside the brake drums and contaminate the drums. Net result- no brakes. Not a good idea.

[Wayward]

I have only been towing an Airstream for a few years but have towed all manner of boat trailers for decades in all sorts of conditions and distances, so take this for what it is worth..

- Bearing Buddy does create a very slight positive pressure inside the hub. As mentioned above, this is very good for boat trailers to keep water from getting in. The pressure is very slight from a very light spring. They are common on boat trailers.

- I have never had a seal blown out by a Bearing Buddy and I routinely pump them with grease if I am towing a trailer with them on. I had a Bearing Buddy itself push out once however due to a poor fit. BUT - if someone pumped the hub full of grease beyond the spring pressure, of course something will give! The Bearing Buddy brand comes with a pressure relief hole for this so it should not be a problem (other brands may not).

- If a Bearing Buddy spring can push out a seal, then I would say the seal fit is far too loose and should be "staked in" or more investigation done on the hub/seal fit.

- Bearing buddy is also helpful on non-boat trailers ( I use them on my utility trailer too) for a few reasons: 1) The bearing and hub can be fully packed. 2) on trailers with brakes, the hub heating/cooling can cause condensation as the air pocket in the hub expands and contracts. 3) A pump of grease now and then moves fresh grease through. 4) a full hub keeps grease on the seal lip extending its life. 5) A Bearing Buddy that is constantly losing pressure is a very good indicator of seal failure.

- There is nothing special about the hub on boat trailers, They are the same as used on utility and other trailers with common pressed-in seals.

- The Bearing Buddy is chrome but another con is some may not look as nice on trailers with center hub caps

Grease may ooze from the seal lip on the back side but I have not seen it work its way into the brakes on boat or utility trailers. If the Airstream's seals open to the inside of the brake drum, this would be a problem. I was going to put them on mine so if anyone knows this is the case, I would like to know too.

[Wayward]

Originally Posted by L911

What size bearing buddies will fit my 73' Ambassador (built in 70').

If you can measure the hub bore , or if someone here knows it, this chart will help.

[L911]

Thanks for the info: Ive got bearing buddies on our boat & they came factory on our Pace enclosed trailer.

So far Ive never had them push a seal out or leak, I wanted them because as you pump grease in the zerk you can see the buddy fill with grease & move out. As long as you stop pumping when the zerk comes almost out, i would think the rear seal should hold, if not it was probably shot anyway...?

[Ag&Au]

Originally Posted by L911

Thanks for the info: Ive got bearing buddies on our boat & they came factory on our Pace enclosed trailer.

So far Ive never had them push a seal out or leak, I wanted them because as you pump grease in the zerk you can see the buddy fill with grease & move out. As long as you stop pumping when the zerk comes almost out, i would think the rear seal should hold, if not it was probably shot anyway...?

There are at least a few (perhaps several) threads on Bearing Buddies on Airforums. They all start similarly. Someone asks if they can use them on their trailer. That is usually followed by at least a few posts from people who haven't used them, but have heard that they don't or won't work. Then someone who has used them posts that they work fine.
I will play the part of the person who has used them.
I have used bearing buddies on my boat trailer and on two previous travel trailers. One for 7 years and one for 10 years. I never experienced any problem whatsoever. I would have them on my current trailer, but it came with Never-Lube hubs.

Now it's time for someone who has used them and had some sort of trouble to come along and tell me I don't know what I'm talking about. So we can standby now for that.

Ken

[samb]

Ever wonder where that grease goes every time you pump some into a bearing buddy?

Away?

[Ag&Au]

Originally Posted by samb

Ever wonder where that grease goes every time you pump some into a bearing buddy?

Away?

No I never did wonder because I know. It goes into the bearing to replace the grease that has evaporated or liquefied and leaked out slowly. If you keep at it long enough it will ooze out around the front plate. Bearing Buddies are not a neat and clean solution and a little will probably end up on the wheels from time to time. However if serviced regularly (like before every trip) they will give years of reliable service. The service involves topping up each wheel with grease. It take about 5 mins for a tandem axle.

Ken

[NorthernWind]

In all my years of repairing trailers and RVs I have had way more problems from units without bearing buddies, than any units that had bearing buddies! Just don't overfill the slide, don't pump the crap out of it until it's out to the cap.