what's up with these tailwheel bearings?

Started installing the tailwheel stuff this afternoon.

As you probably know, there isn't an abundance of guidance on this. and I have a couple of questions to throw about for you guys.

I assume that you just tighten the nut until there's no slop in the wheel and stick a cotter pin in it?

The bearings don't really freewheel more than about 1/2 a revolution, even before it goes in the fork. They "felt" like they were already packed, but I popped one out to make sure and it's a chinese-made sealed ball bearing setup. as I was rotating it, some yellow "dried varnish" looking flakes came out, but there's no real way to pack these. Do you guys just chuck these when they get gritty?

There is a grease zerk in the wheel, but it doesn't have a spring ball in it, and if I pump grease in this it seems unlikely that it will find its way into the bearings. More like it will just make a mess. Is this a placebo or what?

So, to sum up;

1- how tight is too tight on the nut- even with a thin washer, I have to get it maybe 2-3 flats past finger tight to get cotter pin through it.

2- is there any way to pack these bearings? if not how long do they last?

Before anybody brings it up, yeah, I know there are aftermarket setups that are things of beauty, and I'll probably end up with one of those in the long run, but I forgot to delete the Van's supplied stuff from my kit order and it's on hand, so it's going on for now. Am I destined to be upgrading 10 hours in?

It may last more than 10 hrs but not likely much more than that. I know of several suffering premature failures. The bearing are **** and you are correct the grease doesn't get into them.

I would order one of these and have it on hand if you want to avoid downtime.

https://store.vansaircraft.com/6-rubber-lightweight-tailwheel-u-tailwheel-lw-6.html

I've been flying the Vans standard tailwheel (not the same one!) for 23 years and have replaced the bearings three or four times. I buy the bearings from Vans and have never seen defective ones like you describe. The tailwheel will spin several revolutions when given a whirl.

No, you cannot pack these bearings, they are shielded, and the fitting on the wheel is useless. I keep a set on hand and when the bearings on the plane get noisy I replace them. Each tailwheel will usually last long enough for one replacement set.

The axle nut is tightened barely snug and then pinned. Make sure the proper combination of washers and spacers are used to keep everything rotating freely.

This is a good example of why there is so much aftermarket gear available for the RVs ... !

Sam nailed it. It's a poor design that doesn't fit the "aviation" quality standard but has nevertheless been since the first RV. Kind of like the screen door springs and hardware used on the tailwheel arm connection.

Contrary to what you would want to do, there is no way to tighten the axle bolt until it properly captures the inner bearing race in order to prevent it rotating. So what you're left with is a bearing that may turn when it has less drag than the axle to inner race drag. So it's a race (catch what I did there?!) between the drag of the bearing and the drag of the axle to see which one will turn first. Yuk.

I considered making a sleeve that fits inside the wheel and between the inner races that would allow the axle bolt to capture the race. Probable not worth the effort, the bearing would likely just fail earlier.

So there ya go. Grease it all up good and wait for the bearing to get noisy, replace with your spare, repeat.

Cheers

I clean and repack the bearings at each annual. I posted a thread describing my method.
https://vansairforce.net/community/showthread.php?t=202237&highlight=Tail+wheel+grease

Hope that link works.

Lawn mower

When I originally installed mine I noticed they looked just like a lawnmower wheel bearing.
https://www.ebay.com/itm/151222745005

I never bothered to measure as I have since replaced the wheel with a nicer wheel / bearing assembly.
However they make a ball bearing replacement for the cheap ones that is still very inexpensive.

https://www.amazon.com/Bearings-Whe...pcontext&ref_=fplfs&psc=1&smid=A3U13J6MAS1O2R

If the problem is the crappy tire/bearing combo, then a solution is to replace it with a better one.

Virtually maintnance free too. We've had some last for over 1000 hours!

https://flyboyaccessories.com/product-category/tailwheel-products

For those so inclined ...

I was determined to fix the extra tail wheel I had laying around and make it better. Bought two bearings 1 3/8" x .50" from GoVets and made a short sleeve to space the .5" bearing to the 3/8" axle bolt. Press the new bearings into the existing hub, slide the sleeve in and good to go. Smooth as butta ...