-------------- Original message from Mark Steitle <msteitle@gmail.com>: --------------

Update...  

I checked the rivets on my RD2-C damper assembly and was able to confirm that they were in fact beginning to loosen as evidenced by the radial streaks on the damper plate.  I picked four rivets at random, approx. 90 degrees apart, and grabbed the shop heads with vice grips and tried to spin them.  All four would spin with little effort, thus confirming that they were beginning to loosen.  After a phone call to Tracy, we decided to replace the ring of rivets with AN3 bolts, which I've now done.  I'll be watching to see if these show any sign of loosening over time.  I would suggest that checking for smoking rivets on the damper be a regular inspection item during oil changes.  

Mark S.

On Thu, Jan 21, 2010 at 8:47 AM, Mark Steitle <msteitle@gmail.com> wrote:

Tracy,

 

I didn't see any cracks, just streaks radiating out from each rivet.  Unfortunately, I didn't take a picture, and I cleaned the streaks off and reassembled everything.  I'll keep a close eye on it and if/when they reappear, I'll take a picture and send it to you for evaluation. 

 

I will also check to see how tight the bolts are in the bushings.  My concern was that there was evidence of deterioration around the outer perimeter of the bushings.  I think I would feel better if I went ahead and replaced them.  I'll call you and place an order this week for those.  This may be caused by the lower rpm (5100-5200) that I typically run in "economy cruise" mode.  It isn't quite as smooth as running the engine at higher rpms, but the fuel burn is much less.  Everything is a tradeoff. 

 

Thanks,

Mark 

On Wed, Jan 20, 2010 at 10:35 PM, Tracy Crook <tracy@rotaryaviation.com> wrote:

Hi Mark,
  I'd need to know more about the 'streaks' to make a guess.  If they are just oil streaks, that's no big deal.  But if you are talking about cracks, that's a different matter.   I do have the damper rubber parts available.  I have noticed a little 'creap' in the rubber dampers after several hundred hours on my -4 but as long as the hole is not enlarged (still a snug fit on the drive lugs)  they will work fine. 

I only have about 24 hours on my RV-8 so far but everything looks good.

Tracy

 

On Wed, Jan 20, 2010 at 3:28 PM, Mark Steitle <msteitle@gmail.com> wrote:

Hi Tracy,

 

I had my RD2-C gearbox off the a/c over the holidays and noticed some things that I would like your feedback on.  FYI - This gearbox is mounted to a n/a 20B.  It has a total of 153 hours on the gearbox.

 

First, on the flywheel adapter assembly, there is a pattern of streaks leading out radially (like spokes on a wagon wheel) from the circle of rivets.  These are the ones arranged in a large circle holding the center hub to the square aluminum plate (the one with the four rubber snubbers).  Is this normal?  Should I replace the rivets or the adapter?  If I need to replace the rivets, which type/size do you recommend.  Have you seen any of these symptoms on your RV-8? 

 

Also, I noticed some deterioration of the rubber snubbers.  I feel these should be replaced.  Do you sell replacement parts, or can you provide a source for these.  

 

I have not disassembled and inspected the actual gearbox (yet).  However, I do have a chip detector on the drain line and have only noticed very fine metal on the magnet (no large chips).  I check this regularly.  I run Castrol 100% Synthetic oil in the engine/gearbox & premix 2-stroke oil in the gas.

 

Hope you are doing well and the RV-8 is trouble-free (if that is possible).

 

Thanks,

Mark Steitle

512/497-3046