Molded wheel bearing seals

[MARZ]

On 12/4/2020 at 1:08 PM, PT20J said:

It is a double lip seal and and according to the spec sheet (see original post) it is designed specifically to keep water out. 
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I see that now on the 154-12000 seal (by looking at the drawing) but the drawing on 154-12400 doesn't look like it is?

[PT20J]

12 hours ago, MARZ said:

I see that now on the 154-12000 seal (by looking at the drawing) but the drawing on 154-12400 doesn't look like it is?

I installed them on all three wheels. They are both double lip seals.

[skykrawler]

On 12/5/2020 at 1:21 PM, Mooneymite said:

Reminds me of a conversation where one of our local IAs was castigating a previous mechanic who had apparently used boat wheel bearing grease instead of the specfied milspec wheel bearing grease on a plane he was doing an annual on.

A slow talking fellow resident asked him:  "So in a year, how many miles do you think that airplane taxiies?"

The IA opined, " maybe a few miles."

And the slow talker asked, "And how many miles can a boat trailer go on that blue grease?"

There was a period of silence while everyone thought about that.  

 

The logic is fine, but I only put about 50 to 70 hours a year on my airplane and would guess at least 3 miles for each operation at the home airport plus any additional landing elsewhere.  So more than a few.

I clean and repack every year.....but that regulation covers a whole range of aircraft from C152 on up.  It might be more critical for aircraft operating hundreds of hours than on airplanes operating tens of hours.   I see airplanes on ramp with no paint left on the wheels and obvious corrosion, how does that get past an annual?   We can all see the difference between poorly maintained airplanes and well maintained airplanes.  Re-packing wheel bearings is not preventing very many accidents

[Hank]

2 hours ago, skykrawler said:

The logic is fine, but I only put about 50 to 70 hours a year on my airplane and would guess at least 3 miles for each operation at the home airport plus any additional landing elsewhere.  So more than a few.

Good Lord! At my first base, it might have been 1/2 mile from my hangar to the numbers, call it a mile per flight. Then I mived, distance stayed the same. Bought a house, moved the plane, taxi distance went down. Can't imagine a mile and a half each way every time.

But realistically, it's the 1000' of takeoff plus the hjgh-speed part of your landing that matter. Call it a half mile per flight leg.

Edited December 13, 2020 by Hank

[Mooneymite]

7 hours ago, skykrawler said:

The logic is fine, but I only put about 50 to 70 hours a year on my airplane and would guess at least 3 miles for each operation at the home airport plus any additional landing elsewhere.  So more than a few.

In this particular case, the owner lived right on the runway.  The extent of his taxiing was going into position for takeoff, or taxi back after landing.  I would guess his bearings would last a life time even without ever repacking.  How long they would last with unapproved, waterproof, boat trailer grease is anyone's guess.  Technically, no one could argue with the IA, but I might speculate the boat greased bearings would last 2 lifetimes.