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Nose wheel shimmy

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Knicholas2(at)aol.com
Guest

Posted: Sat Apr 04, 2009 6:17 pm Post subject: Nose wheel shimmy

I know this has been discussed in the archives,  but I need some  help.

  

 This winter I replace the nose wheel fork on my RV9A  per Van's  service bulletin.  Since the install,  I have a bad nose wheel shimmy  on landing.  I have tried various torque settings on the axel,   different tire pressures and varied the break-out pressure on the nose wheel  "pivot".  I still get the shimmy on landing - note that it does not occur  on takeoff,  and I have intentionally allowed my take off speed on the  runway to exceed my landing speed.  On take off it does not shimmy,   only on landing.

  

 Does anyone have any helpful ideas?  I feel like the nose wheel is  going to shake right off of the plane, and it is no fun.

  

 Kim Nicholas

 RV9A

 Auburn, WA

 





 Worried about job security? Check out the 5 safest jobs in a recession.

  [quote][b]

ronlee(at)pcisys.net
Guest

Posted: Sat Apr 04, 2009 6:58 pm Post subject: Nose wheel shimmy

Have you verified that the tire is  balanced and not out of round?

  

 Have someone competent observe the tire  upon landing.  The 

 difference between shimmy and out of  round/out of balance is

 obvious.

  

 Ron Lee

    [quote][b]

carl.froehlich(at)cox.net
Guest

Posted: Sat Apr 04, 2009 7:08 pm Post subject: Nose wheel shimmy

You may want to use the Matco axle for the nose gear.  That way you can pre-load the bearings just enough – letting the wheel spin easily, but still fully torque the axle nut.  

Here is the link  http://www.matcomfg.com/AXLEASSEMBLYA24125INCH-idv-3657-1.html  

Get the wheel balance weights from them as well.  



 Carl Froehlich  

RV-8A (450 hrs)  

RV-10 (fuselage)  

       

From: owner-rv-list-server(at)matronics.com [mailto:owner-rv-list-server(at)matronics.com] On Behalf Of Knicholas2(at)aol.com

 Sent: Saturday, April 04, 2009 10:17 PM

 To: rv-list(at)matronics.com

 Subject: Nose wheel shimmy  

  

  

     

I know this has been discussed in the archives,  but I need some help.  

    

   

    

This winter I replace the nose wheel fork on my RV9A  per Van's service bulletin.  Since the install,  I have a bad nose wheel shimmy on landing.  I have tried various torque settings on the axel,  different tire pressures and varied the break-out pressure on the nose wheel "pivot".  I still get the shimmy on landing - note that it does not occur on takeoff,  and I have intentionally allowed my take off speed on the runway to exceed my landing speed.  On take off it does not shimmy,  only on landing.  

    

   

    

Does anyone have any helpful ideas?  I feel like the nose wheel is going to shake right off of the plane, and it is no fun.  

    

   

    

Kim Nicholas  

    

RV9A  

    

Auburn, WA  

    



 

 

   

  

       

  

Worried about job security? Check out the 5 safest jobs in a recession.   	  Quote: 	
		    http://www.matronics.com/Navigator?RV-List 	
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        [quote][b]

robin1(at)mrmoisture.com
Guest

Posted: Sun Apr 05, 2009 8:03 am Post subject: Nose wheel shimmy

Kim,  

            I found that once I upgraded the nose wheel fork on my 6A per the SB the nose wheel shimmy was much worse (never had a problem before). I think there might be something in the geometry that makes it more prone to shimmy. Because I was going on 6 years with the same nose wheel I decided to replace the tire and at the same time have it balanced. It made a big difference in the shimmy. I don’t believe my old tire was out of round but probably out of balance. I concur with Carl that upgrading to the Matco axel is an additional improvement that should help and for $50.00 it’s a no brainer. I have one on my -10 and plan to put one on my 8A.  

            BTW this is something you want to resolve soon as when the shimmy is bad it can really damage the wheel pants quickly.  

   

Good luck  

Robin  

       

From: owner-rv-list-server(at)matronics.com [mailto:owner-rv-list-server(at)matronics.com] On Behalf Of Carl Froehlich

 Sent: Saturday, April 04, 2009 8:07 PM

 To: rv-list(at)matronics.com

 Subject: RE: Nose wheel shimmy  

  

  

   

You may want to use the Matco axle for the nose gear.  That way you can pre-load the bearings just enough – letting the wheel spin easily, but still fully torque the axle nut.  

Here is the link  http://www.matcomfg.com/AXLEASSEMBLYA24125INCH-idv-3657-1.html  

Get the wheel balance weights from them as well.  



 Carl Froehlich  

RV-8A (450 hrs)  

RV-10 (fuselage)  

       

From: owner-rv-list-server(at)matronics.com [mailto:owner-rv-list-server(at)matronics.com] On Behalf Of Knicholas2(at)aol.com

 Sent: Saturday, April 04, 2009 10:17 PM

 To: rv-list(at)matronics.com

 Subject: Nose wheel shimmy  

  

  

     

I know this has been discussed in the archives,  but I need some help.  

    

   

    

This winter I replace the nose wheel fork on my RV9A  per Van's service bulletin.  Since the install,  I have a bad nose wheel shimmy on landing.  I have tried various torque settings on the axel,  different tire pressures and varied the break-out pressure on the nose wheel "pivot".  I still get the shimmy on landing - note that it does not occur on takeoff,  and I have intentionally allowed my take off speed on the runway to exceed my landing speed.  On take off it does not shimmy,  only on landing.  

    

   

    

Does anyone have any helpful ideas?  I feel like the nose wheel is going to shake right off of the plane, and it is no fun.  

    

   

    

Kim Nicholas  

    

RV9A  

    

Auburn, WA  

    



 

   

  

         

  

  

Worried about job security? Check out the 5 safest jobs in a recession.   	  Quote: 	
		     http://www.matronics.com/Navigator?RV-List http://forums.matronics.com http://www.matronics.com/contribution   	
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      [quote][b]

chasb(at)satx.rr.com
Guest

Posted: Sun Apr 05, 2009 12:18 pm Post subject: Nose wheel shimmy

I have had exactly the same nose wheel shimmy that you describe. The shimmy was the result of more than one problem.

I originally had a vertical nose shimmy confirmed by outside observers. It only occurred after landing. I checked for out of round and balance and both were perfect. I found that the nose wheel itself would not spin more than a quarter turn regardless of the torque setting on the axle bolt. After nose wheel touchdown after landing, the tight wheel caused the strut to flex aft and rebound, which lifted the wheel back off the runway. Once off the ground it quickly stopped spinning and the action repeated itself causing the vertical shimmy until I slowed considerably. I switched from Van's supplied nose wheel to a Grove wheel that would spin freely regardless of axle torque. That solved the vertical shimmy problem.

However, I still occasionally had a lateral shimmy at taxi speeds. Tightening the strut/fork pivot bolt beyond Van's recommendations helped, but did not completely solve the problem and the shimmy gradually got worse. I found that even with the axle bolt torqued to the max, the nose wheel still had a slight amount of lateral play on the axle. The answer to that was carefully grinding about a sixteenth inch off the sleeve between the hubs of the Grove wheel. The wheel now has zero lateral play and still turns freely.

Lastly, I found that the nose strut itself was rotating in the motor mount sleeve. The rotation amounted to nearly a quarter of an inch lateral play at the bottom of the tire. The retaining bolt at the top of the strut was not tight enough and the NAS bolt had wallowed out the motor mount holes. A temporary fix was to add a couple of washers to the bolt and tighten it beyond torque recommendations. So far, that stopped the shimmy. 

The loose strut obviously added to the increased shimmy problems. At some future time, I'll have to take action to repair the oversized hole. I suspect that the hole enlargement was caused by the vibration of the strut which was caused by the other shimmy inducing problems. 

 Recommendations: 

Replace Van's supplied nose wheel with a Grove wheel.

Ensure no lateral play of the nose wheel on the axle.

Ensure the nose wheel will spin a couple of turns easily.

Increase the torque on the strut/fork pivot bolt.

Check for the slightest rotation of the nose strut at the motor mount.

Check the nose strut bolt torque (and continue to check frequently.)

Charlie Brame

RV-6A  N11CB

San Antonio





----------------------------------------



Time: 07:17:50 PM PST US

From: Knicholas2(at)aol.com (Knicholas2(at)aol.com)

Subject: Nose wheel shimmy



I know this has been discussed in the archives,  but I need some  help.



This winter I replace the nose wheel fork on my RV9A  per Van's  service 

bulletin.  Since the install,  I have a bad nose wheel shimmy  on landing.  I have



tried various torque settings on the axel,   different tire pressures and 

varied the break-out pressure on the nose wheel  "pivot".  I still get the shimmy



on landing - note that it does not occur  on takeoff,  and I have 

intentionally allowed my take off speed on the  runway to exceed my landing speed.

On 

take off it does not shimmy,   only on landing.



Does anyone have any helpful ideas?  I feel like the nose wheel is  going to 

shake right off of the plane, and it is no fun.



Kim Nicholas

RV9A

Auburn, WA

 [quote][b]

pitts_pilot(at)bellsouth.
Guest

Posted: Sun Apr 05, 2009 3:19 pm Post subject: Nose wheel shimmy

Charles Brame wrote:  	  Quote: 	
		     I have had exactly the same nose wheel shimmy that you describe. The shimmy was the result of more than one problem.

   

   

   I originally had a vertical nose shimmy

 	
 Maybe we can call this 'bounce' to differentiate with shimmy?

  	  Quote: 	
		      confirmed by outside observers. It only occurred after landing. I checked for out of round and balance and both were perfect. I found that the nose wheel itself would not spin more than a quarter turn regardless of the torque setting on the axle bolt. After nose wheel touchdown after landing, the tight wheel caused the strut to flex aft and rebound, which lifted the wheel back off the runway. Once off the ground it quickly stopped spinning and the action repeated itself causing the vertical shimmy until I slowed considerably. I switched from Van's supplied nose wheel to a Grove wheel that would spin freely regardless of axle torque. That solved the vertical shimmy problem.

   

   

   However, I still occasionally had a lateral shimmy

 	
 True shimmy.

  	  Quote: 	
		      at taxi speeds. Tightening the strut/fork pivot bolt beyond Van's recommendations helped, but did not completely solve the problem and the shimmy gradually got worse.

 	
 This will happen while the new belleville washers 'wear in' ....... I guess shimmy would help lessen the wear-in time!   

  	  Quote: 	
		      I found that even with the axle bolt torqued to the max, the nose wheel still had a slight amount of lateral play on the axle. The answer to that was carefully grinding about a sixteenth inch off the sleeve between the hubs of the Grove wheel. The wheel now has zero lateral play and still turns freely.

   

   

   Lastly, I found that the nose strut itself was rotating in the motor mount sleeve. The rotation amounted to nearly a quarter of an inch lateral play at the bottom of the tire. The retaining bolt at the top of the strut was not tight enough and the NAS bolt had wallowed out the motor mount holes. A temporary fix was to add a couple of washers to the bolt and tighten it beyond torque recommendations. So far, that stopped the shimmy. 

   

 	
 Boring out the strut/mount for the next size bolt would be a better 'repair'.  With the elongated holes, the strut will move back and forth over time making things worse.

  	  Quote: 	
		     The loose strut obviously added to the increased shimmy problems. At some future time, I'll have to take action to repair the oversized hole. I suspect that the hole enlargement was caused by the vibration of the strut which was caused by the other shimmy inducing problems. 

   

 	
 I think you're right.

  	  Quote: 	
		      Recommendations: 

   

   

   Replace Van's supplied nose wheel with a Grove wheel

 	
 The new axle/hub should do also.

  	  Quote: 	
		     Ensure no lateral play of the nose wheel on the axle.

   Ensure the nose wheel will spin a couple of turns easily.

 	
 This is contrary to what I've been told.  1/2 turn is sufficient pre-load on the bearings.  Otherwise the wheel tends to vibrate (may take some time) as it slows down.

  	  Quote: 	
		     Increase the torque on the strut/fork pivot bolt.

   Check for the slightest rotation of the nose strut at the motor mount.

   Check the nose strut bolt torque (and continue to check frequently.)

 	
 All good items!

 Linn

 [quote]   

   

   Charlie Brame

   RV-6A  N11CB

   San Antonio

   

   

   

   

   ----------------------------------------

   

   

   

   

   

   

   

 Time: 07:17:50 PM PST US

 From: Knicholas2(at)aol.com (Knicholas2(at)aol.com)

 Subject: Nose wheel shimmy

   

 I know this has been discussed in the archives,  but I need some  help.

   

 This winter I replace the nose wheel fork on my RV9A  per Van's  service 

 bulletin.  Since the install,  I have a bad nose wheel shimmy  on landing.  I have

   

 tried various torque settings on the axel,   different tire pressures and 

 varied the break-out pressure on the nose wheel  "pivot".  I still get the shimmy

   

 on landing - note that it does not occur  on takeoff,  and I have 

 intentionally allowed my take off speed on the  runway to exceed my landing speed.

 On 

 take off it does not shimmy,   only on landing.

   

 Does anyone have any helpful ideas?  I feel like the nose wheel is  going to 

 shake right off of the plane, and it is no fun.

   

 Kim Nicholas

 RV9A

 Auburn, WA

    	  Quote: 	
		  



 href="http://www.matronics.com/Navigator?RV-List">http://www.matronics.com/Navigator?RV-List

 href="http://forums.matronics.com">http://forums.matronics.com

 href="http://www.matronics.com/contribution">http://www.matronics.com/contribution



	
 [b]

HCRV6(at)comcast.net
Guest

Posted: Sun Apr 05, 2009 4:21 pm Post subject: Nose wheel shimmy

Linn,



Just curious why you haven't considered using a taper pin (bolt) at the top of the nose wheel strut.  Several folks with the little wheel at the proper end have had problems with the tail wheel spring working loose at the anti-rotation bolt (the set up looks like the nose wheel strut only slightly smaller) and corrected this by reaming the mount hole and installing a taper pin.



Harry Crosby

RV-6 N16CX, 565 hours



---

denis.walsh(at)comcast.ne
Guest

Posted: Sun Apr 05, 2009 5:08 pm Post subject: Nose wheel shimmy

This is as good a run down as I have seen.  I have around 4000 landings on my 6A, and can verify all these observations.  I, too am inclined to think the new fork assembly is more prone to shake.  I too like the matco assembly, but am sticking with my old original Cleveland wheel and axle as furnished in 1994 or so.



I have three things to add:

1.  Sometimes just increasing or decreasing the nose tire pressure will help.

2.  VERY IMPORTANT to get an observers notes.  Frequently the problem is main wheel shake, which can start the nose going, or vice versa.

3.  Regarding the "upper bolt hogging out the holes at top of strut mount"  problem.  Most RVs I have seen eventually develop this problem.  My latest quick fix seems to be working quite well.  Got  a fender washer with the right size hole.  Put it in a vice and beat it into a curved radius to match the weldment where the strut goes through.  Installed a new bolt with the big ass curved washer under the head.  torqued it down.  \\

I made the curvature a little more than matching to get a springy fit.  Voila I now have a new hole at the top which has a very snug fit (the washer hole shrunk a little laterally when bent), and the rotational slop is gone..

Hoping it will last a year or so, then I can replace the washer and/or install another on the bottom.

On Apr 5, 2009, at 2:17 , Charles Brame wrote:

 	  Quote: 	
		  I have had exactly the same nose wheel shimmy that you describe. The shimmy was the result of more than one problem.

I originally had a vertical nose shimmy confirmed by outside observers. It only occurred after landing. I checked for out of round and balance and both were perfect. I found that the nose wheel itself would not spin more than a quarter turn regardless of the torque setting on the axle bolt. After nose wheel touchdown after landing, the tight wheel caused the strut to flex aft and rebound, which lifted the wheel back off the runway. Once off the ground it quickly stopped spinning and the action repeated itself causing the vertical shimmy until I slowed considerably. I switched from Van's supplied nose wheel to a Grove wheel that would spin freely regardless of axle torque. That solved the vertical shimmy problem.

However, I still occasionally had a lateral shimmy at taxi speeds. Tightening the strut/fork pivot bolt beyond Van's recommendations helped, but did not completely solve the problem and the shimmy gradually got worse. I found that even with the axle bolt torqued to the max, the nose wheel still had a slight amount of lateral play on the axle. The answer to that was carefully grinding about a sixteenth inch off the sleeve between the hubs of the Grove wheel. The wheel now has zero lateral play and still turns freely.

Lastly, I found that the nose strut itself was rotating in the motor mount sleeve. The rotation amounted to nearly a quarter of an inch lateral play at the bottom of the tire. The retaining bolt at the top of the strut was not tight enough and the NAS bolt had wallowed out the motor mount holes. A temporary fix was to add a couple of washers to the bolt and tighten it beyond torque recommendations. So far, that stopped the shimmy. 

The loose strut obviously added to the increased shimmy problems. At some future time, I'll have to take action to repair the oversized hole. I suspect that the hole enlargement was caused by the vibration of the strut which was caused by the other shimmy inducing problems. 

 Recommendations: 

Replace Van's supplied nose wheel with a Grove wheel.

Ensure no lateral play of the nose wheel on the axle.

Ensure the nose wheel will spin a couple of turns easily.

Increase the torque on the strut/fork pivot bolt.

Check for the slightest rotation of the nose strut at the motor mount.

Check the nose strut bolt torque (and continue to check frequently.)

Charlie Brame

RV-6A  N11CB

San Antonio





----------------------------------------



Time: 07:17:50 PM PST US

From: Knicholas2(at)aol.com (Knicholas2(at)aol.com)

Subject: Nose wheel shimmy



I know this has been discussed in the archives,  but I need some  help.



This winter I replace the nose wheel fork on my RV9A  per Van's  service 

bulletin.  Since the install,  I have a bad nose wheel shimmy  on landing.  I have



tried various torque settings on the axel,   different tire pressures and 

varied the break-out pressure on the nose wheel  "pivot".  I still get the shimmy



on landing - note that it does not occur  on takeoff,  and I have 

intentionally allowed my take off speed on the  runway to exceed my landing speed.

On 

take off it does not shimmy,   only on landing.



Does anyone have any helpful ideas?  I feel like the nose wheel is  going to 

shake right off of the plane, and it is no fun.



Kim Nicholas

RV9A

Auburn, WA

  	  Quote: 	
		  

href="http://www.matronics.com/Navigator?RV-List">http://www.matronics.com/Navigator?RV-List

href="http://forums.matronics.com">http://forums.matronics.com

href="http://www.matronics.com/contribution">http://www.matronics.com/contribution



	


	


 [quote][b]

pitts_pilot(at)bellsouth.
Guest

Posted: Sun Apr 05, 2009 7:03 pm Post subject: Nose wheel shimmy

Well, I really didn't think of that ...... and the choice would be determined by the amount of damage in the wallowed out holes and if they're different on either side.  You could ream from the larger hole side and not 'waste' any more tube area on the smaller side with the tapered approach where the standard bolt size increases by 1/16th.  And the fact that I have a drill set/bolts instead of the tapered reamer/pins would probably drive my decision.  Reaming with a straight reamer would mean that the tapered pin would only align one side of the tube and cut the torsional strength in half.  If I'm missing something here, please let me know.

 Linn

 

 [quote]   p { margin: 0; }   Linn,

   

 Just curious why you haven't considered using a taper pin (bolt) at the top of the nose wheel strut.  Several folks with the little wheel at the proper end have had problems with the tail wheel spring working loose at the anti-rotation bolt (the set up looks like the nose wheel strut only slightly smaller) and corrected this by reaming the mount hole and installing a taper pin.

   

 Harry Crosby

 RV-6 N16CX, 565 hours

 [b]

pitts_pilot(at)bellsouth.
Guest

Posted: Sun Apr 05, 2009 7:09 pm Post subject: Nose wheel shimmy

Since I haven't got to the gear on the RV-10 (and I'm not an RV repeat offender) I gather that there's only one bolt to pin the nose gear.  My Grumman (AA-1B) which uses the same strut/socket attachment has two bolts.  The Grummans don't have an issue with the attachment ...... but the assembly method requires the strut and socket to be liberally coated with zinc chromate and installed wet.  It could be this 'glue' that makes the biggest difference.

 Linn

 

 Denis Walsh wrote: [quote]This is as good a run down as I have seen.  I have around 4000 landings on my 6A, and can verify all these observations.  I, too am inclined to think the new fork assembly is more prone to shake.  I too like the matco assembly, but am sticking with my old original Cleveland wheel and axle as furnished in 1994 or so.   

   

   I have three things to add:

   

   

   1.  Sometimes just increasing or decreasing the nose tire pressure will help.

   

   

   2.  VERY IMPORTANT to get an observers notes.  Frequently the problem is main wheel shake, which can start the nose going, or vice versa.

   

   

   3.  Regarding the "upper bolt hogging out the holes at top of strut mount"  problem.  Most RVs I have seen eventually develop this problem.  My latest quick fix seems to be working quite well.  Got  a fender washer with the right size hole.  Put it in a vice and beat it into a curved radius to match the weldment where the strut goes through.  Installed a new bolt with the big ass curved washer under the head.  torqued it down.  \\

   

   

   I made the curvature a little more than matching to get a springy fit.  Voila I now have a new hole at the top which has a very snug fit (the washer hole shrunk a little laterally when bent), and the rotational slop is gone..

   

   

   Hoping it will last a year or so, then I can replace the washer and/or install another on the bottom.

      On Apr 5, 2009, at 2:17 , Charles Brame wrote:

       	  Quote: 	
		            I have had exactly the same nose wheel shimmy that you describe. The shimmy was the result of more than one problem.

     

     

     I originally had a vertical nose shimmy confirmed by outside observers. It only occurred after landing. I checked for out of round and balance and both were perfect. I found that the nose wheel itself would not spin more than a quarter turn regardless of the torque setting on the axle bolt. After nose wheel touchdown after landing, the tight wheel caused the strut to flex aft and rebound, which lifted the wheel back off the runway. Once off the ground it quickly stopped spinning and the action repeated itself causing the vertical shimmy until I slowed considerably. I switched from Van's supplied nose wheel to a Grove wheel that would spin freely regardless of axle torque. That solved the vertical shimmy problem.

     

     

     However, I still occasionally had a lateral shimmy at taxi speeds. Tightening the strut/fork pivot bolt beyond Van's recommendations helped, but did not completely solve the problem and the shimmy gradually got worse. I found that even with the axle bolt torqued to the max, the nose wheel still had a slight amount of lateral play on the axle. The answer to that was carefully grinding about a sixteenth inch off the sleeve between the hubs of the Grove wheel. The wheel now has zero lateral play and still turns freely.

     

     

     Lastly, I found that the nose strut itself was rotating in the motor mount sleeve. The rotation amounted to nearly a quarter of an inch lateral play at the bottom of the tire. The retaining bolt at the top of the strut was not tight enough and the NAS bolt had wallowed out the motor mount holes. A temporary fix was to add a couple of washers to the bolt and tighten it beyond torque recommendations. So far, that stopped the shimmy. 

     

     

     The loose strut obviously added to the increased shimmy problems. At some future time, I'll have to take action to repair the oversized hole. I suspect that the hole enlargement was caused by the vibration of the strut which was caused by the other shimmy inducing problems. 

     

     

      Recommendations: 

     

     

     Replace Van's supplied nose wheel with a Grove wheel.

     Ensure no lateral play of the nose wheel on the axle.

     Ensure the nose wheel will spin a couple of turns easily.

     Increase the torque on the strut/fork pivot bolt.

     Check for the slightest rotation of the nose strut at the motor mount.

     Check the nose strut bolt torque (and continue to check frequently.)

     

     

     Charlie Brame

     RV-6A  N11CB

     San Antonio

     

     

     

     

     ----------------------------------------

     

     

     

     

     

     

     

 Time: 07:17:50 PM PST US

 From: Knicholas2(at)aol.com (Knicholas2(at)aol.com)

 Subject: Nose wheel shimmy

     

 I know this has been discussed in the archives,  but I need some  help.

     

 This winter I replace the nose wheel fork on my RV9A  per Van's  service 

 bulletin.  Since the install,  I have a bad nose wheel shimmy  on landing.  I have

     

 tried various torque settings on the axel,   different tire pressures and 

 varied the break-out pressure on the nose wheel  "pivot".  I still get the shimmy

     

 on landing - note that it does not occur  on takeoff,  and I have 

 intentionally allowed my take off speed on the  runway to exceed my landing speed.

 On 

 take off it does not shimmy,   only on landing.

     

 Does anyone have any helpful ideas?  I feel like the nose wheel is  going to 

 shake right off of the plane, and it is no fun.

     

 Kim Nicholas

 RV9A

 Auburn, WA

      	  Quote: 	
		  

href="http://www.matronics.com/Navigator?RV-List">http://www.matronics.com/Navigator?RV-List

href="http://forums.matronics.com">http://forums.matronics.com

href="http://www.matronics.com/contribution">http://www.matronics.com/contribution



	
     

   



 href="http://www.matronics.com/Navigator?RV-List">http://www.matronics.com/Navigator?RV-List

 href="http://forums.matronics.com">http://forums.matronics.com

 href="http://www.matronics.com/contribution">http://www.matronics.com/contribution



	
 [b]

kahamer(at)bigpond.net.au
Guest

Posted: Sun Apr 05, 2009 9:29 pm Post subject: Nose wheel shimmy

The nose gear leg of my 7A was able to rotate slightly at the engine mount end.  

Tightening the bolt would fix the problem for a few landings.  

I ended up using LOCTITE 680(and the bolt of course) on the upper and lower socket and no problem after 90 landings.  

Would have to use a heat gun if the leg has to come off again…..  

Don’t know if anyone else has tried this before.  

   

Regards  

   

Karl  7A  60hours  

Near Sydney/Australia  

     

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 04/05/09 10:54:00

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HCRV6(at)comcast.net
Guest

Posted: Mon Apr 06, 2009 9:06 am Post subject: Nose wheel shimmy

Linn, 

  

Of course there would be no advantage to using a taper pin in a straight reamed hole.  You need a taper reamer.  Archives should turn up more info on this and references to sources for the pins and reamers.



Harry Crosby

RV-6 N16CX, 565 hours



---

chasb(at)satx.rr.com
Guest

Posted: Tue Apr 07, 2009 3:22 pm Post subject: Nose wheel shimmy

With regard to repairing a wallowed out bolt hole in the top of the  

nose gear strut:  Is there any way to drill, taper, or ream the hole  

without pulling the engine?



Charlie Brame

RV-6A  N11CB

San Antonio

bicyclop(at)pacbell.net
Guest

Posted: Tue Apr 07, 2009 9:31 pm Post subject: Nose wheel shimmy

Yes, but it's not easy. I did our 6 with an angle drill, for the 

undersize hole, and then drove the taper ream with an air powered 

ratchet. I took off some of the exhaust system for better access. It was 

still a difficult reach and took me most of 2 days. It was worth it 

though. The nose gear leg really wiggled before and is rock solid now. 

Aircraft spruce has the taper pins and stuff.



Have fun with it.



Ed Holyoke



Charles Brame wrote:

 	  Quote: 	
		   



 With regard to repairing a wallowed out bolt hole in the top of the 

 nose gear strut:  Is there any way to drill, taper, or ream the hole 

 without pulling the engine?



 Charlie Brame

 RV-6A  N11CB

 San Antonio

chasb(at)satx.rr.com
Guest

Posted: Wed Apr 08, 2009 5:26 am Post subject: Nose wheel shimmy

With regard to a wallowed out bolt hole in the top of the nose wheel  

strut:



A couple of my compatriots suggested tack welding the lower bushing to  

the motor mount in about three places. The welds would prohibit any  

rotation of the strut while not affecting the vertical movement of the  

strut. It would not allow removal of the gear strut without grinding  

the welds off, but removal of the nose strut is seldom required, if  

ever.



Any comments, pros or cons?



Charlie Brame

RV-6A N11CB

San Antonio

pitts_pilot(at)bellsouth.
Guest

Posted: Wed Apr 08, 2009 5:42 am Post subject: Nose wheel shimmy

Not sure what the heat from the welding would do to the temper of the strut.  Just a thought.  The other thought is that you might want to remove the strut to check for corrosion (rust) since failure of the strut would be pricey.

 Linn

 

 Charles Brame wrote: [quote]--> RV-List message posted by: Charles Brame <chasb(at)satx.rr.com> (chasb(at)satx.rr.com)   

   

 With regard to a wallowed out bolt hole in the top of the nose wheel strut:   

   

 A couple of my compatriots suggested tack welding the lower bushing to the motor mount in about three places. The welds would prohibit any rotation of the strut while not affecting the vertical movement of the strut. It would not allow removal of the gear strut without grinding the welds off, but removal of the nose strut is seldom required, if ever.   

   

 Any comments, pros or cons?   

   

 Charlie Brame   

 RV-6A N11CB   

 San Antonio   

   

   

   

   

   

   

   

   

   

   

   

   

   

   

   

   

   

   

   

   

   

   

   

   

    	  Quote: 	
		  

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