Aligning and Drilling RV-8 Landing Gear attachments
Authors note: I cannot be held responsible for any errors that are contained in this article so please don’t follow blindly 
Van's instructions explain how to get everything setup and aligned, which appears to be a bit of nonsense. After failing to get suitable edge distance alignment with the plumb bobs I did a search on VAF and came across some interesting ideas and carried out the following:
Only used the outboard plumb bobs to check the distance to the tail plumb bob (1/8" - allowance is 1/4"). As I didn't have any angle (without cutting it up) I used some straight wood clamped to the axle face and this showed the axle faces of the legs were not parallel. So I then went to Chapter 10-1 and dug out DWG 45 and decided to fit the axles and do the toe in check with the taught thread and spacer.
Placed the landing gear central in the housing and in particular I made sure that the outboard wear plate was 3/16" from the F-843 lower longeron edge (as DWG 74 and photo below) – the edge distance after drilling worked out as near perfect as you could expect.
Did the toe check and found the right was spot on and the left had a toe in of 1.5 degrees - when I moved the gear to get it to zero the edge distance was all to pot. So I will order from Van's the 1 and 1/2 degree axle shims mention in Chapter 10-1
My personal view is that whilst it is important to get the axle faces parallel I think edge distance is a major priority - small errors of the axle face can be shimmed. Really it would be better if Vans had you look at Chapter 10 at the same time as you drill the gear as it says "the gear legs were aligned during fuselage construction, so the axles should be very close to the desired position......if the axles are not aligned they may be shimmed". You get the impression from Chapter 8 that you are setting it up so that it is the desired position!

They then say to match drill a 3/8" hole down through the outer bracket, through the lower longerons and through the gear plate. I think a better way to do this is an idea from VAF that I have modified slightly and worked well for me. Basically you secure the wear plate with the outer bolts to keep it really secure for when you drill the larger sizes. I only had a ¼” reamer so if you have the larger reamers amend the drill sizes accordingly:
DO NOT USE THE PNEUMATIC DRILL (it will overheat your compressor!)
– I used a good quality electric mains powered drill and it worked great.
Use cobalt/high quality drill bits and drilling oil (Boelube).
Drill the 7/16” hole in the inboard wear plate as per Vans instructions on the drill press.
1. Insert the 7/16th bolt at the inboard end.
2. Set up the gear in the proper alignment as described above.
(Drilling Outer Wear Plate Holes into the
Floor/Longeron/Weldment))
3. Mark around the outer and inner wear plates with a sharpie for later reference.
4. Use a ¼” transfer punch (bought a set from eBay £11.50 + P&P) to locate the exact centre of the two outer ¼” bolts in the outboard wear plate.
5. Drill the punched hole with a #40 then #30.
6. Drill again with a 7/32”.
7. Ream 1/4".
8. Bolt this end with a 1/4" bolt.
9. Repeat the process with the other end and secure both with washers and nut.
10. Use a 3/8” transfer punch through the bracket hole.
11. Remove the bracket, drill the punched hole with a #40 then #30.
12. Put the bracket back on, making sure you have a bolt or something through the other end to keep it aligned.
13. Drill it out with a 7/32” then 3/8 ”
14. Place a bolt in this hole, transfer punch the other, drill as before.
(Drilling Inboard Wear Plates into the Floor/Weldment)
The inboard wear plates are a bit simpler.
15. Check the inboard wear plate is lined up with the pen marks made at step 3.
16. Transfer punch through the 5/16” bolt hole, drill #40 then #30
17. Again to 7/32” then 5/16 ” .
18. Place a bolt in this hole, transfer punch the other, drill as before.
19. The outboard holes are most easily done by using a ¼” transfer punch up from the underside, then remove the wear plate and drill it on a drill press. I started with #40 then #30, #21, #12 and 7/32” then reamed 1/4”.

I will use JC5A jointing compound under the wear plates and use multipurpose grease on the non-powder coated parts (there is another story as I had corrosion under the powder coating and had to remove it, apply Red
Oxidiser then Hamerite paint – Van’s refunded the cost of this as it was no doubt cheaper than shipping new gear legs as they weigh a ton!)
Bob Ellis www.rv-8.co.uk
October 2009