Installing Gear Bolts

[pilot28906]

I am reading on the forums about reaming the gear weldments and gear bolt holes with a .311" reamer, however I do not see this in the build manual or prints. Is it called out somewhere? Also, before reading about the reamer, I cleaned out the powder coat from the weldment bolt holes with a 5/16" drill; will this be a problem? I have not done anything to the gear bolt hole.

RV7

thanks

[rvbuilder2002]

Originally Posted by pilot28906

I am reading on the forums about reaming the gear weldments and gear bolt holes with a .311" reamer, however I do not see this in the build manual or prints. Is it called out somewhere? Also, before reading about the reamer, I cleaned out the powder coat from the weldment bolt holes with a 5/16" drill; will this be a problem? I have not done anything to the gear bolt hole.

RV7

thanks

Possibly

If you measure an AN5 bolt (the size used for the gear leg attachment) it typically is .311. That is .0015 under 5/16 (.3125") A difference of .0015 is a very loose fit for a fastener.

That is why the manual specifies using a either a metric sized drill (7.9mm I think) or a .311 reamer to final size the holes

Also, only one of the leg attach bolt holes in the weldment are close to final size (upper hole). The lower hole is under size and supposed to be final drilled with the gear leg in place. This is done to assure perfect hole alignment.

[YellowJacket RV9]

One of my gear leg holes ended up very slightly oversized as well. General Aircraft Hardware, http://www.gen-aircraft-hardware.com sells NAS bolts that have 1/32 and 1/64 oversize shanks, I believed labeled as -X and -Y. With one of these bolts and the appropriately sized reamer, you should be good to go (with Van's blessing, of course). I didn't have good luck with an adjustable reamer - I'd suggest just buying a quality one of the proper size.

Chris

[pilot28906]

Thanks Scott and Chris. Where in the manual is this called out for the RV7? I have read that section twice (and print) and can not find any mention of the reamer or metric bit.

[BillL]

Originally Posted by pilot28906

Thanks Scott and Chris. Where in the manual is this called out for the RV7? I have read that section twice (and print) and can not find any mention of the reamer or metric bit.

John, on the topic of "can't find in the drawings" right now, take note - ALL holes in the center wing spar (upper forward) need bolts. There are 4 locations for an3-12A apparently not on the drawings, or very hard to find.

Sorry, can not help on the gear but it appears you have all the information now.

[bret]

Originally Posted by pilot28906

I am reading on the forums about reaming the gear weldments and gear bolt holes with a .311" reamer, however I do not see this in the build manual or prints. Is it called out somewhere? Also, before reading about the reamer, I cleaned out the powder coat from the weldment bolt holes with a 5/16" drill; will this be a problem? I have not done anything to the gear bolt hole.

RV7

thanks

Yip, I made this mistake, the tire will move fore and aft about 3/8" Not good, had to barrow that special reamer and buy the special NAS bolts, but now they are tight with no movement. I think there is a small section for the nose gear bolt that uses the same dia bolt for the main gear that states that the .311 reamer should be used. I think the plans should highlight that with color rainbows and stars here is where I got mine http://www.gen-aircraft-hardware.com/

[pilot28906]

I'll be ordering the reamer and bolts.