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Tim(at)MyRV10.com
Guest

Posted: Wed Aug 09, 2006 8:37 pm Post subject: Serious Front Axle Maintenance Issue on the RV-10

So that "small nosewheel shimmy" I've mentioned for the past couple

of weeks....



Tonight I found that the old posts someone previously made on this

subject REALLY need to be not only investigated fully, but I

completely believe that basically EVERY RV-10 will have this

problem if you do not plan ahead and do something about it before it

happens to you.



Check out this Front Axle and Fork wear write-up:

http://www.myrv10.com/N104CD/maintenance/20060809/index.html

If you read my write-up, you'll see that I previously even called

Van's after someone else had the problem, trying to proactively

"fix" the issue, even though I wasn't fully aware of exactly how

the problem manifested itself.  What REALLY would be nice is if people

find things like this, post some pictures and an explanation.

A picture is worth 1000 words, and it makes it much easier to

understand.  Had I known about this before, I would not be in this

position today.  My front Fork is now worn with a groove, and my

temper is lit.  Tomorrow I'll be calling again to find out if

there is already a "fix" that is finally publicly known...and then

I'll add it to the above page.



Additionally, this has prompted me to stay up a little extra tonight

and lay the groundwork for the "Maintenance Issue" section of the

RV-10 Tips page at:



http://www.myrv10.com/tips/index.html



Hopefully I can get some good input from others about things that

everyone really needs to watch for once they start flying.  Lets

keep these planes in the air, and keep them safe.



-- 

Tim Olson - RV-10 N104CD - Flying

henkjan(at)zme.nl
Guest

Posted: Wed Aug 09, 2006 10:51 pm Post subject: Serious Front Axle Maintenance Issue on the RV-10

Hi Tim,



I did not like the construction of the front wheel bearing and made a

change even before putting my 10 on it's wheels because I had fear about

exactly what happened to your front wheel.

Van's provides two bushing made from thin wall stainless steel tubing

for mounting at the outside of the bearings only, this will not prevent

the bearing inner rings from rotating at the shaft, due to the heavy

seals my inner rings were rotating at the shaft, I didn't like that,

feared that the bushings would damage the fork, your experience proves

that.



Here's what I did, first I determined the distance between the bearing

inner rings, then I made an aliminium bushing on the lathe just a little

wider than the measured distance ( 0.1 to 0.2 mm) to give the bearings

just that little play that they need.

Then I made two aluminium bushings for the outside, dimensions just so

that the total of the two outside bushings, the two bearing inner rings

and the inside bushing are a little bit longer then the shaft, it all

clamps together during assembly.

I did not use the bushings supplied by Van's.

Now it's assembled it's a very rigid construction that allows the

bearings just to rotate at the point that they should as well as both

seals.

Need to say that the length of the bushing between the inner rings needs

to be measured for every wheel separately due to tolerances of the

wheels. 



I can disassemble it again and post pictures if you want.

Henkjan van der Zouw

#40355, sorry, still building.........





 



-----Oorspronkelijk bericht-----

Van: owner-rv10-list-server(at)matronics.com

[mailto:owner-rv10-list-server(at)matronics.com] Namens Tim Olson

Verzonden: donderdag 10 augustus 2006 6:36

Aan: rv10-list(at)matronics.com

Onderwerp: Serious Front Axle Maintenance Issue on the RV-10






So that "small nosewheel shimmy" I've mentioned for the past couple

of weeks....



Tonight I found that the old posts someone previously made on this

subject REALLY need to be not only investigated fully, but I

completely believe that basically EVERY RV-10 will have this

problem if you do not plan ahead and do something about it before it

happens to you.



Check out this Front Axle and Fork wear write-up:

http://www.myrv10.com/N104CD/maintenance/20060809/index.html

If you read my write-up, you'll see that I previously even called

Van's after someone else had the problem, trying to proactively

"fix" the issue, even though I wasn't fully aware of exactly how

the problem manifested itself.  What REALLY would be nice is if people

find things like this, post some pictures and an explanation.

A picture is worth 1000 words, and it makes it much easier to

understand.  Had I known about this before, I would not be in this

position today.  My front Fork is now worn with a groove, and my

temper is lit.  Tomorrow I'll be calling again to find out if

there is already a "fix" that is finally publicly known...and then

I'll add it to the above page.



Additionally, this has prompted me to stay up a little extra tonight

and lay the groundwork for the "Maintenance Issue" section of the

RV-10 Tips page at:



http://www.myrv10.com/tips/index.html



Hopefully I can get some good input from others about things that

everyone really needs to watch for once they start flying.  Lets

keep these planes in the air, and keep them safe.



-- 

Tim Olson - RV-10 N104CD - Flying

Tim(at)MyRV10.com
Guest

Posted: Thu Aug 10, 2006 3:40 am Post subject: Serious Front Axle Maintenance Issue on the RV-10

Thanks Henkjan, I only wish I had a mill handy again, but my friend

who's I used moved away.  It sounds like you did exactly what needs

to be done, but it's a 1-off solution.   I'd love to see photos

of yours or anyone's assemblies that they've fixed, but I don't

want to see you disassemble just for photos.  Thanks for the

description of the fix though.  External photos would be nice.

I'd love to see how big that piece is that fits next to the bearings.



Tim Olson - RV-10 N104CD - Flying

do not archive

Henkjan van der Zouw wrote:

 	  Quote: 	
		   

 

 Hi Tim,

 

 I did not like the construction of the front wheel bearing and made a

 change even before putting my 10 on it's wheels because I had fear about

 exactly what happened to your front wheel.

 Van's provides two bushing made from thin wall stainless steel tubing

 for mounting at the outside of the bearings only, this will not prevent

 the bearing inner rings from rotating at the shaft, due to the heavy

 seals my inner rings were rotating at the shaft, I didn't like that,

 feared that the bushings would damage the fork, your experience proves

 that.

 

 Here's what I did, first I determined the distance between the bearing

 inner rings, then I made an aliminium bushing on the lathe just a little

 wider than the measured distance ( 0.1 to 0.2 mm) to give the bearings

 just that little play that they need.

 Then I made two aluminium bushings for the outside, dimensions just so

 that the total of the two outside bushings, the two bearing inner rings

 and the inside bushing are a little bit longer then the shaft, it all

 clamps together during assembly.

 I did not use the bushings supplied by Van's.

 Now it's assembled it's a very rigid construction that allows the

 bearings just to rotate at the point that they should as well as both

 seals.

 Need to say that the length of the bushing between the inner rings needs

 to be measured for every wheel separately due to tolerances of the

 wheels. 

 

 I can disassemble it again and post pictures if you want.

 

 

 Henkjan van der Zouw

 #40355, sorry, still building.........

 

 

 

 

  

 

 -----Oorspronkelijk bericht-----

 Van: owner-rv10-list-server(at)matronics.com

 [mailto:owner-rv10-list-server(at)matronics.com] Namens Tim Olson

 Verzonden: donderdag 10 augustus 2006 6:36

 Aan: rv10-list(at)matronics.com

 Onderwerp: Serious Front Axle Maintenance Issue on the RV-10

 

 

 

 So that "small nosewheel shimmy" I've mentioned for the past couple

 of weeks....

 

 Tonight I found that the old posts someone previously made on this

 subject REALLY need to be not only investigated fully, but I

 completely believe that basically EVERY RV-10 will have this

 problem if you do not plan ahead and do something about it before it

 happens to you.

 

 Check out this Front Axle and Fork wear write-up:

 http://www.myrv10.com/N104CD/maintenance/20060809/index.html

 

 

 If you read my write-up, you'll see that I previously even called

 Van's after someone else had the problem, trying to proactively

 "fix" the issue, even though I wasn't fully aware of exactly how

 the problem manifested itself.  What REALLY would be nice is if people

 find things like this, post some pictures and an explanation.

 A picture is worth 1000 words, and it makes it much easier to

 understand.  Had I known about this before, I would not be in this

 position today.  My front Fork is now worn with a groove, and my

 temper is lit.  Tomorrow I'll be calling again to find out if

 there is already a "fix" that is finally publicly known...and then

 I'll add it to the above page.

 

 Additionally, this has prompted me to stay up a little extra tonight

 and lay the groundwork for the "Maintenance Issue" section of the

 RV-10 Tips page at:

 

 http://www.myrv10.com/tips/index.html

 

 Hopefully I can get some good input from others about things that

 everyone really needs to watch for once they start flying.  Lets

 keep these planes in the air, and keep them safe.

rvbuilder(at)sausen.net
Guest

Posted: Thu Aug 10, 2006 6:19 am Post subject: Serious Front Axle Maintenance Issue on the RV-10

Man, someone didn't have their coffee yet when they designed that.

Before even reading your write-up or looking at the pictures the first

thing that popped into my head was a washer.  I can't believe they put

in a SS bushing against an aluminum fork and didn't realize this would

happen.  Duh.



  Simplest and quickest fix is exactly what you are thinking Tim.  Get a

large SS fender washer to take up the force from the bushing and spread

it out on the fork.  Check the usual suspects such as McMaster-Carr or

worst case fabricate your own.



  Someone was asleep at the wheel on this one.



Michael Sausen

RV-10 #352 Buildus Interuptus due to moving

Do Not Archive

--

Vern(at)teclabsinc.com
Guest

Posted: Thu Aug 10, 2006 7:04 am Post subject: Serious Front Axle Maintenance Issue on the RV-10

Hi Tim,



On my old Cessna 150 they used caps (in place of the bushing U-1023)

that fits over the end of the shaft (U-1009). When the shaft is bolted

to the fork the cap is held in place by the compression between the bolt

head and the end of the shaft. I never really understood the why it was

designed that way until looking at your pictures.



If the shaft size is the same you may be able to pick up some used caps

for a Cessna and use these to replace the bushings.



Vern (#40324 wings) do not archive



--

Ray.R.Doerr(at)sprint.com
Guest

Posted: Thu Aug 10, 2006 7:28 am Post subject: Serious Front Axle Maintenance Issue on the RV-10

I didn't have much luck with Van's on this issue as well.  My A

& P caught this issue before I had the plane inspected and what we came

up with is to shave .040 off the aluminum axle itself so the wheel won't

slide side to side.  Once I did this the wheel was solidly in the middle

in the axle with enough force on the bearings so as to create a slight

drag on the tire when trying to turn it by hand.

	I will check on mine tonight and report back.  I currently have

106 hours on my plane.

Thank You

Ray Doerr

40250

N519RV (Flying)

--

Tim(at)MyRV10.com
Guest

Posted: Thu Aug 10, 2006 7:43 am Post subject: Serious Front Axle Maintenance Issue on the RV-10

I have some new info on the Axle issue.   I'll post the text here,

but I updated the web page for better readability.



http://www.myrv10.com/N104CD/maintenance/20060809/index.html

---

Refer to page 46-06 on your plans for visual information

I both figured out an idea, and just got off the phone with Gus at 

Van's.  Yes, they are aware of the issue.  Apparently they did change 

the U-1023 spacers that are delivered with the kits and now instead of 

thin stainless steel, they're thick aluminum spacers, that should spin 

less easily, especially stuck against the similar aluminum, as it might 

tend to gall and stick.  He didn't know why they didn't make it an S.B. 

and send out new parts.  So, this is DEFINITELY something to address for 

anyone who hasn't yet, and these parts should be available free.  This 

isn't to say that the new fix is ideal, but certainly better than what I 

had to fly with for 100+ hours.



The NOSE FORK ASSY part is somewhere around $160, for those who are 

interested.  I may end up doing that, depending on how paranoid I 

am....which remains to be seen.



I am getting the new spacers via UPS ground, instead of overnight, 

because I also have one other thing that I'd like to try and accomplish. 

   Personally, I think I know what needs to be done to protect those 

forks.  Today at fastenal I found 3/8" ID x 1.5" OD stainless fender 

washers and they're .050" thick.  A very similar Aviation hardware 

washer would be the AN970-6, which are only 12 cents at Van's and are 

1-5/8" diameter and .063 thick.   The idea is that if that U-1009 axle 

is cut down in length by the same thickness as 2 of those washer, you 

could then install a large-area flat washer against the fork, and that 

would prevent EVER having that fork wear.  You never want to 

unnecessarily wear an expensive part.   So, on my order is a few 

AN970-6's, -7's, and a new U-1009 axle.  The axle was about $15, and I 

ordered it so that I could allow these parts to ship UPS ground, and 

still feel good about chopping up my old U-1009 and shortening it at a 

local machine shop so I can put these washers in for the weekend.  If 

the new spacers work fine with my shortened axle and washers, then I 

will just leave it that way permanently.  Small price to pay to fix the 

issue fast....less than an hours' flight time.  The bigger problem is 

until I either get over it, or buy a new fork assy, I'm going to have 

that nagging thought of the fork damage.  There's still about .290-.300 

thickness to that fork, which should be good, especially if you hold 

that nosewheel off well on landing.



More photos to come as things come together...

-----

Tim Olson - RV-10 N104CD - Flying



 	  Quote: 	
		   

 Check out this Front Axle and Fork wear write-up:

 http://www.myrv10.com/N104CD/maintenance/20060809/index.html

 

 

 If you read my write-up, you'll see that I previously even called Van's

 after someone else had the problem, trying to proactively "fix" the

 issue, even though I wasn't fully aware of exactly how the problem

 manifested itself.  What REALLY would be nice is if people find things

 like this, post some pictures and an explanation.

 A picture is worth 1000 words, and it makes it much easier to

 understand.  Had I known about this before, I would not be in this

 position today.  My front Fork is now worn with a groove, and my temper

 is lit.  Tomorrow I'll be calling again to find out if there is already

 a "fix" that is finally publicly known...and then I'll add it to the

 above page.

 

 Additionally, this has prompted me to stay up a little extra tonight and

 lay the groundwork for the "Maintenance Issue" section of the RV-10 Tips

 page at:

 

 http://www.myrv10.com/tips/index.html

 

 Hopefully I can get some good input from others about things that

 everyone really needs to watch for once they start flying.  Lets keep

 these planes in the air, and keep them safe.

 

 --

 Tim Olson - RV-10 N104CD - Flying

jack.lockamy(at)navy.mil
Guest

Posted: Thu Aug 10, 2006 7:54 am Post subject: Serious Front Axle Maintenance Issue on the RV-10

Why not just drill a single hole in each side of the fork and into the spacers just forward or aft of the axle bolt?  Counter sink the hole(s) on the outside of the fork (both sides), tap the hole in the spacer for a #8 screw, insert a #8 countersunk/flush screw in each hole and you're done!  No way that spacer is gonna rotate...  

I did this on my RV-7A before this was ever even mentioned as I could see that the spacer could easily rotate and cause the fork to be 'grooved'.  So far the 'preventive measure' taken above has proved to work, took less than 10 minutes and I didn't even need a lathe...  

Jack Lockamy  

N174JL RV-7A 210 hrs  

Camarillo, CA  

www.jacklockamy.com

mike(at)cleavelandtool.co
Guest

Posted: Thu Aug 10, 2006 8:03 am Post subject: Serious Front Axle Maintenance Issue on the RV-10

Back in the 80's and early 90's before the full swivel tail wheel all the

tail dragger RVs had a similar problem with the tail wheel.  We made a kit

to fix it using the same idea as Henkjan.  I don't know if it would be

possible to make a kit for this if the wheels vary in thickness, but if

someone finds a solution I would be happy to make a kit of the parts.



Mike Lauritsen

Cleaveland Aircraft Tool

2225 First St. 

Boone, Iowa 50036

515-432-6794

mike(at)cleavelandtool.com

--

Tim(at)MyRV10.com
Guest

Posted: Thu Aug 10, 2006 8:12 am Post subject: Serious Front Axle Maintenance Issue on the RV-10

Ray,



You may still want to protect that fork.



I've got you beat on hours, but only by 1 hour....107.4.

Man, you're flying the pi$$ out of that thing!  Good job!



Tim Olson - RV-10 N104CD - Flying

do not archive

Doerr, Ray R [NTK] wrote:

 	  Quote: 	
		   


	


 	  Quote: 	
		   	I will check on mine tonight and report back.  I currently have

 106 hours on my plane.

Tim(at)MyRV10.com
Guest

Posted: Thu Aug 10, 2006 8:19 am Post subject: Serious Front Axle Maintenance Issue on the RV-10

Yep, in my write-up, that's actually my proposed method of fixing

the rotation.  I think this stuff should be done during the initial

build, and nobody even have a problem to talk about...especially

now that they'll have a thicker spacer, it would be easy to do.



Tim Olson - RV-10 N104CD - Flying

do not archive

Lockamy, Jack L wrote:

 	  Quote: 	
		   Why not just drill a single hole in each side of the fork and into the 

 spacers just forward or aft of the axle bolt?  Counter sink the hole(s) 

 on the outside of the fork (both sides), tap the hole in the spacer for 

 a #8 screw, insert a #8 countersunk/flush screw in each hole and you're 

 done!  No way that spacer is gonna rotate...

 

 I did this on my RV-7A before this was ever even mentioned as I could 

 see that the spacer could easily rotate and cause the fork to be 

 'grooved'.  So far the 'preventive measure' taken above has proved to 

 work, took less than 10 minutes and I didn't even need a lathe...

 

 Jack Lockamy

 N174JL RV-7A 210 hrs

 Camarillo, CA

 www.jacklockamy.com

bhughes(at)qnsi.net
Guest

Posted: Thu Aug 10, 2006 8:54 am Post subject: Serious Front Axle Maintenance Issue on the RV-10

Mike,



This is one problem Van's should fix and very soon. This is be a Service

Bulletin. 



Bobby

(40116)



--

acs(at)acspropeller.com.a
Guest

Posted: Thu Aug 10, 2006 2:28 pm Post subject: Serious Front Axle Maintenance Issue on the RV-10

Tim, fantastic idea. I'm glad someone like yourself is taking the time to

help the rest of us out with these information issues.

Following is an extract from an email sent to me a few days ago,



"returned the nosewheel to Matco to have it replaced with WHLNW511.25 which

is correct for the valve stem on the tube and avoids the clearance problem

with the supplies WHLNW501.25."



As I'm no where near my plans at the moment I don't know if it is relevant

to your findings, is an issue or can even help.



I'd also suggest adding to your maint issues, the clearance issue with the

elevator trim motor and as someone has mentioned in the last few days the

co-pilot left rudder pedal clearance on the tunnel wall. Both could pose

safety issues down the track.

John 40315



--

wayne.e(at)grandecom.net
Guest

Posted: Thu Aug 10, 2006 4:37 pm Post subject: Serious Front Axle Maintenance Issue on the RV-10

I'm currently building in Justin, TX in George0 Orndorff's hangar, he's the one that makes the RV building videos and is also a0 Van's tech center, and I was talking to him about this problem, wondering if I0 needed to take some type of action on mine. His response to me on this issue was0 that this was a quite common occurrence on the RV's. He said the reason he0 believes it happens is that when the builder tightens down the bolt holding on0 the bushing and tire that they tighten it down too much. He said I should just0 tighten it down just until it's snug. Then after flying it for 5 or 10 hours0 check it and retighten it. Do this over the first 20 or 30 hours. 

  

 I have a friend who is an A&P and also a DAR0 and I called him and ask him the same question. He agreed with George. He said0 to tighten the bolt down until a little grease comes out of the bearing and then0 back it off a little and then keep an eye on it for awhile.

  

 This may not be the case on Tim's plane though?0 

  

 For what ever it's worth.

  

 Wayne Edgerton #40336

rvbuilder(at)sausen.net
Guest

Posted: Thu Aug 10, 2006 5:39 pm Post subject: Serious Front Axle Maintenance Issue on the RV-10

They are basically correct.  However I disagree with their solution.  When you have two metals of this dissimilar of a hardness rubbing together with such a small surface area something is going to give eventually.  You need to spread that across a more substantial area.  Even my cheap wheelbarrow has this provision.  

   

Michael  

       

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Wayne Edgerton

 Sent: Thursday, August 10, 2006 7:36 PM

 To: rv10-list(at)matronics.com

 Subject: Re: Serious Front Axle Maintenance Issue on the RV-10  

  

  

     

I'm currently building in Justin, TX in George Orndorff's hangar, he's the one that makes the RV building videos and is also a Van's tech center, and I was talking to him about this problem, wondering if I needed to take some type of action on mine. His response to me on this issue was that this was a quite common occurrence on the RV's. He said the reason he believes it happens is that when the builder tightens down the bolt holding on the bushing and tire that they tighten it down too much. He said I should just tighten it down just until it's snug. Then after flying it for 5 or 10 hours check it and retighten it. Do this over the first 20 or 30 hours.   

    

   

    

I have a friend who is an A&P and also a DAR and I called him and ask him the same question. He agreed with George. He said to tighten the bolt down until a little grease comes out of the bearing and then back it off a little and then keep an eye on it for awhile.  

    

   

    

This may not be the case on Tim's plane though?   

    

   

    

For what ever it's worth.  

    

   

    

Wayne Edgerton #40336

toaster73(at)earthlink.ne
Guest

Posted: Thu Aug 10, 2006 6:22 pm Post subject: Serious Front Axle Maintenance Issue on the RV-10

Here is a link where one can learn a lot about0 tapered roller bearings, and the proper design intent. Granted our nosewheels0 won't see as many miles or speeds as a BMW motorcyle, but I found the article0 very informative. I don't have the nosewheel yet so I don't know exactly how it0 all goes together , but from Tim's pictures it looks pretty cheesy.

 -Chris Lucas

 #40072

 R75/5

 do not archive

toaster73(at)earthlink.ne
Guest

Posted: Thu Aug 10, 2006 6:23 pm Post subject: Serious Front Axle Maintenance Issue on the RV-10

Oops forgot the link

  

 http://w6rec.com/duane/bmw/wheel_bearing/index.htm

  

 [quote]   ---

Tim(at)MyRV10.com
Guest

Posted: Thu Aug 10, 2006 8:41 pm Post subject: Serious Front Axle Maintenance Issue on the RV-10

Wayne, for what it's worth, I really don't think this will work

that way on the RV-10.  I may be wrong, but I think you really need

to tighten that thing well on this plane or you'll REALLY have problems.

I'm betting that the assembly those guys are familiar with isn't the

same thing as what we have.  If you have any looseness, you're going

to really screw up your axle.   I just updated that page....scroll

to the bottom to read tonights update.  I got a little long winded again

(surprise surprise), but I explained the axle and rotation and other

things in a bit of depth.  For you -10 builders, that page is really

worth understanding, just so you can ponder it and know what's going

on there....even if you come to some other conclusion.  (if you do,

let me know...I'd love to hear it, or hear exactly what the mechanics

are that George thinks would be better if it were looser)



I'll post the text of tonights update here again, but you would be

much better served to just read it on the page, and see the latest

photos.  This is just for the archive's sake.



Here's the link again.

http://www.myrv10.com/N104CD/maintenance/20060809/index.html



---

Today I stopped by a machine shop and had them take off about .115" off 

my axle, to accomodate 2 AN970-6 washers on the outer edge.  Yes, they 

are .063 each, so .126" would have been the standard, but I wanted the 

axle to be even just a little more snug than before, because any flexing 

inward will bring that valve cap closer to the fork.    As a side note, 

this from John D. today...a note someone sent him:



"returned the nosewheel to Matco to have it replaced with WHLNW511.25 

which is correct for the valve stem on the tube and avoids the clearance 

problem with the supplies WHLNW501.25."



In other words, Van's is sending out the wrong wheel for the application 

on this plane...because they use this wheel for the RV-7's and such, and 

didn't want to have to stock 2 parts.  So we get to receive the one that 

isn't made for the application, and therefore unless you swap wheels, 

you're going to have minimal valve stem clearance.....pretty nice, huh? 

  <not>



Anyway, I had the axle cut shorter at a machine shop, and then I just 

had to guesstimate how much to take off the 2 spacers.  Knowing they had 

worn into a taper on the inside, to fit against the bearing, I had them 

only cut down by .085" total.  I did .035" on one side, and .050" on the 

other.  That way I could have a slightly longer sleeve on the left side, 

so my valve stem had just that little extra clearance from the fork. 

This brought forth a small problem...  Tonight when I assembled it as in 

the first photo below, it looked great.  VERY much better than original. 

  Then, when I put the whole wheel together, I found that the spacers 

had worn probably at least .120" because there was tons of slop in the 

spacers yet, even though they now had a nice flat surface to sit 

between, and had been cut less than the axle, and the washers were in 

there to fill in some space.  The spacers just spun.  So, I decided 

since I already ordered another axle, I'd take my bandsaw and VERY 

carefully trim off some more axle, and just use one more washer on the 

left side.  That should keep that valve stem even FURTHER away.  If I 

was right, I could get it so there would be plenty of pressure on the 

bearings and spacers to hold them in place so they don't spin.  Sure 

enough, it worked just great.  I could now torque that bolt down tight 

and keep the spacers from spinning, and the bearing too.  Just to be 

totally sure they never spun again, I drilled a couple of holes in the 

stainless spacers, and remounted it all.  Then I made a pilot hole in 

the aluminum axle shaft, and took it all apart and tapped it for an 8-32 

screw on each spacer.  Then I cleaned it up, regreased, and put it all 

together.  Now it is very solid, and should never wear the fork 

again....I just am left with a crappy fork...so I'll probably just get a 

new one.   Once my new spacers and axle come in, I may tear it all apart 

and use those pieces, but I'll still probably cut the axle and spacers 

down and use the washers on the outer ends.  It will prevent your forks 

from being the sacrificial component.  The bearing, for future 

reference, is a Timken LM-6700-LA (I think that's right, but I'll 

re-check tomorrow)



A note about tightening the axle nut...   Tonight on the RV-10 list, 

someone said that George Orndorff (A Van's tech center place), says that 

the bolt should only be snugged, and then rechecked often in the first 

few hours.  I don't personally believe this is true on the RV-10, but 

perhaps it is on the other models.  Here's why.   I studied this long 

and hard, and now I fully understand why this is such a huge freaking 

issue.  It didn't make sense at first, having worked on dozens and 

dozens of automotive bearings in the past.  You see, on automotive apps, 

the bearings are pressed in on the backside, and a nut and washer holds 

the bearing tight.   But it pushes against a different area of the 

bearing.  And the grease seal is usually a seal that is pressed into the 

hub, with a seal around the shaft on the ID of the seal.   This is NOT 

how these bearings are on this application.   On THIS application, you 

are expecting that the sleeves, the axle, the bolt, AND the inner race 

area of the bearing do not ever rotate.  The problem is, if these 

bearings were a tight knurled, or press fit onto that axle shaft, it 

might be easy to keep them from rotating by just not letting the shaft 

spin.  But, what happens here is that the grease seal is a large seal 

that the wheel spins around....so the seal is on the OD of the bearing 

in this case.  That's why my stinking seals were so torn when the wheel 

wobbled.   The kicker to the problem is, if you don't have the spacers 

very tight against the bearing, there's not enough force to keep the 

bearing from turning on the shaft.  If the bearing spins on the axle 

shaft, then it's becoming USELESS as a bearing.  At that point, you're 

using the aluminum axle as the bushing, and the wheel is rolling by 

spinning the hard steel bearing race against your soft aluminum axle 

shaft.....instead of turning the roller bearings inside of the wheel's 

outer race.  The seal itself has a lot of drag against the wheel as it 

spins, and this drag will make it so that the wheel tries REALLY hard to 

make the bearing spin.  As it turns out, if you don't have tight 

spacers, it's really easy to get that bearing spinning.  And once the 

bearing is spinning, the spacers stuffed right up against it will spin 

too.  And once they start spinning, they'll spin against the fork.  If 

you have the stainless ones like me, they'll ABSOLUTELY then start 

carving into your forks.  If you have the new and improved thick 

aluminum ones (that I can't comment firmly on because I haven't seen 

them), then they would have more surface area against both the bearing 

and the fork....so on one hand the bearing will try to turn it harder, 

but the fork will prevent it harder as well.   To me, this is STILL 

going to be a less than ideal situation until you PREVENT the spacers 

from turning, and you PROTECT the forks from being worn if they do turn. 

   The lock screws I put in should keep the spacers still.  The washers 

will protect the forks.   The one further improvement that would be 

simple would be to drill a tiny hole in the fork on one side, that 

drills into the aluminum axle, and then tap for a small hex head 

internal setscrew lock, so that you could pin the axle from rotating at 

all too.   Beyond that, the only real improvement I could think of is if 

you could find a way to either press-fit, or hold that inner bearing 

from turning on the axle.  Perhaps knurling it, epoxy, a small keyway 

and shear key, or something like that would be the ticket.  If you've 

done all of the other steps, and have tight spacers, you probably 

wouldn't have any huge issues from that point.



The worst thing about it is that no matter what you do, you really don't 

have independent control over how tight the bearings are 

seated...separate from how tight the axle bolts are and how long the 

spacers are.  Just to let you know how this all ends up the way I have 

it tonight, the wheel will not continue rolling if you spin it by hand. 

  I don't think it's too tight from a bearing perspective, but the 

grease seals against the wheel hub provide a lot of drag, so they don't 

let the wheel spin real freely.



A couple other tips, while I'm at it.  By the time you get to 25 hours 

on your plane, re-check that large nut that holds the fork on.  Mine 

needed to be tightened almost one full flat to the next castle stop, to 

retorque it after it took it's set.  I think the spec is about 24lbs. 

pull of breakout force to rotate the nose at an angle.



The second tip that I can't yet verify is fairing balance.  To prevent 

shimmy, I've heard that a good idea is to balance your fairing.  Since I 

had a little lead shot around, and I wanted this all to be perfect now, 

tonight I weighed out a little lead and taped it to the nose of the 

nosewheel fairing.  I got it so that I could hold it where it mounts, in 

the centers of those 4 screw areas, and get it to be about neutrally 

balanced.   Then I just took a little shot away, poured the rest into 

the nose of the fairing, and mixed a couple of squirts of epoxy.  I 

poured the epoxy into the nose over the shot, put down one layer of 

cloth, and then a little more epoxy.  By tomorrow that stuff won't be 

going anywhere, and I already re-checked the balance and it's now much 

less tail heavy, so maybe that will improve things too.



---

Tim Olson - RV-10 N104CD - 107 hours Flying



Wayne Edgerton wrote:

 	  Quote: 	
		   I'm currently building in Justin, TX in George Orndorff's hangar, he's 

 the one that makes the RV building videos and is also a Van's tech 

 center, and I was talking to him about this problem, wondering if I 

 needed to take some type of action on mine. His response to me on this 

 issue was that this was a quite common occurrence on the RV's. He said 

 the reason he believes it happens is that when the builder tightens down 

 the bolt holding on the bushing and tire that they tighten it down too 

 much. He said I should just tighten it down just until it's snug. Then 

 after flying it for 5 or 10 hours check it and retighten it. Do this 

 over the first 20 or 30 hours.

  

 I have a friend who is an A&P and also a DAR and I called him and ask 

 him the same question. He agreed with George. He said to tighten the 

 bolt down until a little grease comes out of the bearing and then back 

 it off a little and then keep an eye on it for awhile.

  

 This may not be the case on Tim's plane though?

  

 For what ever it's worth.

  

 Wayne Edgerton #40336

ddddsp1(at)juno.com
Guest

Posted: Thu Aug 10, 2006 10:03 pm Post subject: Serious Front Axle Maintenance Issue on the RV-10

Tim, 

Are you planning to drill thru the fork into the axle and TAP it with a contersunk screw to keep the axle from turning like you did to the spacer?  I am thinking it would be easy to do and would eliminate the axle from turning even if the wheel got loose. 

Dean 

Getting engine today. 



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Tim(at)MyRV10.com
Guest

Posted: Fri Aug 11, 2006 3:42 am Post subject: Serious Front Axle Maintenance Issue on the RV-10

Yeah, but not until I get all the new parts and see them.

That's one hole I'll "drill once".



Tim Olson - RV-10 N104CD - Flying

ddddsp1(at)juno.com wrote:

 	  Quote: 	
		   Tim,

 

 Are you planning to drill thru the fork into the axle and TAP it with a 

 contersunk screw to keep the axle from turning like you did to the 

 spacer?  I am thinking it would be easy to do and would eliminate the 

 axle from turning even if the wheel got loose.

 

 Dean

 

 Getting engine today.

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