What's new
Van's Air Force

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

RV6 Tail stinger bolt

Scott Hersha

Well Known Member
I have an RV6 that I built from a used kit that has gone through a couple builders (or more) before me. My tail stinger rod was the original bent rod that came with RV3, 4, and early RV6’s. I modified it for a full swivel Doug Bell tailwheel unit. One thing that bothered me was that the stinger rod seemed to rotate slightly when bolted into the tailwheel weldment. I installed a close tolerance AN4 bolt to make it more secure. That helped, but it still has some slight movement rotationally. What I would like to do is ream the hole for the bolt oversize and install an oversized bolt. The bolt as called out in the plans is an AN4-14A. My research has told me that an oversized replacement for this might be an NAS2904-18 bolt. The grip diameter is .2641-.2651 on this NAS bolt. The AN4 bolt as called out in the plans has a diameter of .246-.249. So the NAS2904 bolt is between an AN4 & an AN5 (5/16).

Has anyone here dealt with this situation? Any recommendations? Where can I get a reamer of an appropriate size? I’m pretty sure the hole inaccuracy is in the weldment, not the stinger.
 
Some of us are using taper pins in place of bolts in that area.
 
Thanks Mike for that info. I thought about using a taper pin, but didn’t think I could get a TP reamer down in that area to make it work. Assuming it needs to be reamed from the top down In assembly (this is a flying airplane)……. And well….. I’ve never done it. But that would be the best solution - I agree. I will be researching that now. Your link to past history with parts/tools advise is great.

Unfortunately, none of those links to the tools needed work anymore, but it gives me a starting place.

Thanks.
 
Last edited:
At the risk of ridicule: Some of us ignored best-practices and Reamed it from the bottom.
 
Thanks Mike for that info. I thought about using a taper pin, but didn’t think I could get a TP reamer down in that area to make it work. Assuming it needs to be reamed from the top down In assembly (this is a flying airplane)……. And well….. I’ve never done it. But that would be the best solution - I agree. I will be researching that now. Your link to past history with parts/tools advise is great.

Unfortunately, none of those links to the tools needed work anymore, but it gives me a starting place.

Thanks.
Just a few weeks ago I installed a taper pin in this location in the F1 I am building, and did it from the bottom up - should work just fine, and frankly it was the only way to actually do it. I have no fear that the lock nut will fail and the pin fall out…
 
Thanks Paul. That’s what I was just thinking. Much easier vs impossible. There were some negative reviews on ACS about the B&S reamers. What reamer did you use?
 
Just did this last week in my Rocket. Cut an access hole in the lower skin, reamed the hole and used an oversize Hi Lok. Also injected some JB Weld to act as a shim for the socket.
 
Yep, we replaced a tailwheel spring on a RV-6 last month and went to an oversize bolt (because we had one) however its still not right. It's better, but not 100%. It seems to us that the taper-pin is the best way forward and we're presently heading down that road. As reported by others, it will be from the bottom up!
 
I ran into a similar issue on an RV-7 -- the tail spring would "thunk" and move a bit if the tail wheel assembly was rotated. Added an AN960-416 washer under the bolt head (top side), changed the nut to an MS21042-4 and reassembled using the higher torque values for the MS21042. Thunk gone. YMMV.
 
https://cdn.shopify.com/s/files/1/0...e_Changing_a_Mounting_Socket.pdf?v=1692739405 includes tapered pin info

And here's some other useful tailwheel maintenance documents for your amusement:
 
Back
Top