What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Main wheel install questions

prkaye

Well Known Member
FOr the folks with the side-by-side seaters, a couple of questions about main wheel installation...

1) I inflated to 25 PSI. I find that because these wheels are so small (compared to cars) that the pressure drops off very quickly when even a tiny bit of air is let out. I'm trying to check that they're holding air by re-checking every 5 min or so, but the little bit of air that seeps out every time I check seems to drop the pressure noticeably. So I have trouble mainiaining a reading of 25PSI. Also, I wonder if the new inner tubes have some "stretch" and have to be filled a few times before they will hold the pressure?

2) The axle nut. The plans just say to "tighten carefully" before drilling the cotter pin holes. But how tight? Just firmly by hand? I don't have a wrench socket or crowfoot adapter big enough to fit around that huge nut!

3) Plans say to reinstall the inside brake shoe with bolts and safety wire. I see the bolt heads are drilled, but after passing through the bolt heads, where should the safety wire go?

4) The nuts provided with my wheels for the bolts that hold the two wheel-halfs together are not of the "nyloc" type (just metal). I've heard others have nyloc ones. Is it OK that mine don't have any nylon?
 
Last edited:
I'm no expert, but my thoughts:

1) Pump them up to 35 psi (I run 38 for flight, but that is in an -8, so may not apply), and let them sit a week, then check them. They're probably holding air!

2) If you "tighten" the axle nut, the wheel won't turn. What we want is for there to be no significant freeplay, yet for the wheel to turn freely. Tighten it down by hand until there is no side-to-side play, then check the wheel spin. if it drags quickly to a stop, loosen the nut a smidge. Play with it until the wheel spins, and you can't really move it side-to-side, and drill your nut!

3) The safety wire goes between the two bolts in an "S" fashion - they tie to each other!

4) Mine came with Nylon lock nuts, and that is what I continue to use. I guess an argument could be made that if the brakes/wheels get really hot, the Nylon could creep. I think I'll try to not ride the brakes that hard....;)
 
Thanks Paul. Regarding (2), the only dragging that I experience is on the brake pads themsevles. Since the brake pad assembly essentially just "floats", there's nothing holding the pads themselves off teh rotor even when the brakes are open. Is this OK?
 
Phil, the axle threads are pretty rough, and there was a problem a while back where the nuts were not threaded all the way---at least for the 10, not sure if all models were effected.

Before you try to install the wheels, it is a good idea to make sure the nut will thread on the axle freely, and full depth.

Clean the axle and the nut well, make sure no burrs or machining debris are present. Lightly oil, and run on by hand.

If you can do this, then go on to putting on the wheel, it will be much easier to correctly set the bearing tension.

If the only drag you are seeing is form the brake pads, your nuts are probably too loose:eek:

Good luck.
 
Last edited:
Thanks Paul. Regarding (2), the only dragging that I experience is on the brake pads themsevles. Since the brake pad assembly essentially just "floats", there's nothing holding the pads themselves off teh rotor even when the brakes are open. Is this OK?

Yes - I'd do all the axle nut adjustment without the brake pads installed, so you get a true feelign for the whel bearing drag by itself.

Paul
 
I pumped my tires up to 35 psi and was a bit disappointed to see the pressure drop the next day. I kept adding air to maintine the pressure, and after a few days things settled down. I think it takes a while for the tire to stretch out a bit, giving the false impression that the tire is leaking.
 
1/4-20

Another question, for the big allen-key bolt that goes through the axle, the plans say to use a 1/4-20 self-locking nut. I can't find these in my kit. What is the AN number?
I did find AN365-428, which are 1/4-28. could these be used?
 
FOr the folks with the side-by-side seaters, a couple of questions about main wheel installation...

1) I inflated to 25 PSI. I find that because these wheels are so small (compared to cars) that the pressure drops off very quickly when even a tiny bit of air is let out. I'm trying to check that they're holding air by re-checking every 5 min or so, but the little bit of air that seeps out every time I check seems to drop the pressure noticeably. So I have trouble mainiaining a reading of 25PSI. Also, I wonder if the new inner tubes have some "stretch" and have to be filled a few times before they will hold the pressure?

2) The axle nut. The plans just say to "tighten carefully" before drilling the cotter pin holes. But how tight? Just firmly by hand? I don't have a wrench socket or crowfoot adapter big enough to fit around that huge nut!

3) Plans say to reinstall the inside brake shoe with bolts and safety wire. I see the bolt heads are drilled, but after passing through the bolt heads, where should the safety wire go?

4) The nuts provided with my wheels for the bolts that hold the two wheel-halfs together are not of the "nyloc" type (just metal). I've heard others have nyloc ones. Is it OK that mine don't have any nylon?

#1. Why not air it up and leave it over night and recheck the pressure?
Unless you have a rather large leak you will not measure a difference
in 5 minutes.

#3. Sounds like you need to get a copy of FAA AC43.13 (or similar) It is full of information for aircraft tech. (has diagrams showing how to properly use safety wire in different situations).
 
Ack

Ack another question. I'll also repeat the one above and number them both :)

5) for the big allen-key bolt that goes through the axle, the plans say to use a 1/4-20 self-locking nut. I can't find these in my kit. What is the AN number? I did find AN365-428, which are 1/4-28. could these be used?

6) From the plans it appears that only one MS24665-359 Cotter pins go through each axle to retain the axle nut. But there are 6 holes around around the axle nut, suggesting 3 cotter pins per nut, crossing in the middle. Which is true?
 
Another question, for the big allen-key bolt that goes through the axle, the plans say to use a 1/4-20 self-locking nut. I can't find these in my kit. What is the AN number?
I did find AN365-428, which are 1/4-28. could these be used?

No.

This is a special allen head bolt with course threads A 1/4-20 bolt is 1/4 in. diam with 20 threads per inch (instead of 28 threads per inch).
The nuts you are looking for are not AN nuts.
The 1/4-20 nuts would have been in the same bag that the allen bolts were in. I think they are typically silver in color.
 
6) From the plans it appears that only one MS24665-359 Cotter pins go through each axle to retain the axle nut. But there are 6 holes around around the axle nut, suggesting 3 cotter pins per nut, crossing in the middle. Which is true?

Have you installed any AN310 castelated nut on AN bolts with cotter pins?
At this point in construction I am sure you have.

Consider the axle nut to be the same. It has multiple holes to allow for adjustment should you ever install new bearings and races in the wheel, etc.
You only drill a hole for one cotter pin.
Use a 12" #30 extension drill and drill from one side.
Put a long AN470-4 rivet in the hole to prevent teh nut from rotating and then drill the hole on the other side.
Remove the rivet and run the drill all the way through to make sure the holes align with each other.
 
nuts

The 1/4-20 nuts would have been in the same bag that the allen bolts were in

Nope, that was bag 1968-1 with the fuselage kit. It was only screws in that bag.

I read all the bag lists and can't find those nuts anywhere. THis is very frustrating.
 
Lets see...If you still have the original box that the wheel bearings came in, look at who the manufacturer is. I think mine were from Cleveland. I found instructions on their web site on how to torque down the nuts to get the proper preload.

Once you get the axle nut torqued the way you want it, use whichever holes are most convenient for you to drill. At this point, you want to think about future maintenance issues and pulling the wheels will be high on the "condition" list. Use the holes that is most easy to use time and time again.

The Allen headed screws are not AN hardware. I have had very limited success finding 1/4-20 threaded stuff with an AN designation.
 
I'm ordering new nuts from vans since I can't find mine. On the webstore they're listed as:

REPLACES: AN363-420
NUT 1/4-20 SELF LOCK

What does that mean, replaces? Is that an obsolete AN number for that nut? I assume this is the one i want?
 
I'm ordering new nuts from vans since I can't find mine. On the webstore they're listed as:

REPLACES: AN363-420
NUT 1/4-20 SELF LOCK

What does that mean, replaces? Is that an obsolete AN number for that nut? I assume this is the one i want?
Just pick them up at any hardware store! 1/4-20 nylon lock nuts-stainless steel
 
Last edited:
Concerning the reference to the AN363-420 nut...as used on the main wheel brake flange...

I do not remember where I read or heard this, but from what I remember, there was an issue with the initial call out in the plans where the nut-in-use would either crack, or split. The solution was to change to a 1/4-20 self locking nut, and they may have also changed the bolt call out as well.

I am looking at the 11 x 17 preview plans, DWG C2, Rev R2, dated 11/13/00. This page shows a detail F-F. The nut call out is 1/4-20 self locking nut, but the bolt call out is 5/16-20 x 1.5 screw. Well....there's your problem :eek:

I don't remember what I actually used, but I think I followed my -6A build plans.

This C2 drawing is supposed to cover the RV-4's, 6's, 7's, and 8's.
 
Concerning the reference to the AN363-420 nut...as used on the main wheel brake flange...

I do not remember where I read or heard this, but from what I remember, there was an issue with the initial call out in the plans where the nut-in-use would either crack, or split. The solution was to change to a 1/4-20 self locking nut, and they may have also changed the bolt call out as well.

I am looking at the 11 x 17 preview plans, DWG C2, Rev R2, dated 11/13/00. This page shows a detail F-F. The nut call out is 1/4-20 self locking nut, but the bolt call out is 5/16-20 x 1.5 screw. Well....there's your problem :eek:

I don't remember what I actually used, but I think I followed my -6A build plans.

This C2 drawing is supposed to cover the RV-4's, 6's, 7's, and 8's.

Actually it's not a problem. It is a special allen bolt that is 5/16" diam but has 1/4-20 threads on the end. You do need a 1/4-20 nut.
 
YES!! I do remember that now Scott. Kind of like a "sholder'd" bolt. Thanks for the memory jog...
 
torque?

Related question, what torque value should I use for the 1/4-20 self-locking nuts on those allen-key bolts?

**EDIT - nevermind, found it in the handbook... 40-50 inch pounds.
 
Last edited:
I cannot find the hardware!!

Can anyone tell me which bag the bolts / nuts that attach the brake flange to the gear legs?

They are identified on drawing C2 View F-F only as "5-16 x 20 x 1 1/2 SCREW" and "1/4-20 SELF LOCKING NUT"

The instructions mention that they are supposed to be Allen head screws?

I've looked over my packing lists 4x and cannot find them :(
 
Dave,

Memory says it's a 5/16 diameter shoulder bolt. It should stand out like a sore thumb since the shank is bigger than the threaded tip and is shiny from being smoothly ground.
 
Thanks Bill!! I found them based on your description. They are shipped in the FUSELAGE kit, not the Finish Kit!!!!

Now to find the darn special nuts !
 
Wrench

Most Walmarts and Auto parts stores sell a large wrench used typically for trailer-ball installs. Fits RV wheel nuts fine.

Usually 10-12 bucks.

Good for self defense also!
 
No, its the 1/4-20 lock nuts that I can't find. I think they were shipped in the Fuselage kit too. I checked them off, so they are SOMEWHERE... but I give up. I'll order some more!

For the axle nuts I bought the cool little wrench kit from Vans. Its small, light, and seems like it will work fine.
 
No, its the 1/4-20 lock nuts that I can't find. I think they were shipped in the Fuselage kit too. I checked them off, so they are SOMEWHERE... but I give up. I'll order some more!

For the axle nuts I bought the cool little wrench kit from Vans. Its small, light, and seems like it will work fine.

1/4-20 lock nuts should be available at most auto parts or hardware stores. 1/4-20 is the ol' standard course thread.
 
1/4-20 lock nuts should be available at most auto parts or hardware stores. 1/4-20 is the ol' standard course thread.
Up to this point, I've avoided using any generic hardware on the plane... But I think if I can get a nylon locknut for these shoulder bolts at the local NAPA, I'll be ok with it. I don't think these nuts are too critical, and they will be easy to inspect.
 
Back
Top