Page 40A-06, Elastomer Pads, Washers

Periodically Inspect the elastomer pad and the elastomers with weight off the nose wheel.

Over time, a gap between the elastomer pad and the first elastomer will develop. When this gap develops, install a second isolator washer on top of the first (trimming is not required.)

Two washers have been provided. Up to three washers may be installed before replacement of the elastomers is required.

Click to expand...

Just curious how many of you have had to add additional isolator washers and if so at how many hours?

Have not yet added a washer at 500 hours.

150 hours and mine is very loose. About 1/8" to 3/16". I have a bad shake so I need to do this.

I had been having an issue with nose gear/wheel shimmy for a bit. At first, I thought is was just the wheel nut might need a tiny turn because I had just greased it right before the problem started, and on the VAF forums they had mentioned this. Tightened the nut 1 notch in the castle and put the cotter pin back in. Didn't notice much difference.

Second, I had also just put on a new nose tire, so I thought maybe it was out of round. Put back on the old tire, again very little difference.

Finally, today I was taxiing with a setting sun, and I could see my nose gear shadow. When the shimmy started I looked at the shadow and saw that it wasn't the wheel at all, but the entire nose gear assembly that was shaking. Went back to the hangar, put her in and drove around the other hangars until I could find a second person to lean on the tail so I could check the nose gear. Man did it wobble. I noticed about 1/8" to maybe 3/16" of a gap between the top of the 4 elastomers and the Elastomer Pad.

Van's says add 1 or 2 washers under the spring to tighten it up. NO MORE THAN 3 TOTAL WASHERS CAN BE USED! When it loosens up after 3 washers, then all 4 elastomers need to be replaced.

I added one at around 70 hours. There was ever so slightly movement so I preempted.

P.S. I never understood "trimming is not required" as how it would fit of the other one. So, I trimmed it.

I added a 2nd U-1002 isolation washer at 84 hours total time, after jacking the nose gear and finding 1/4? fore-aft slack in the assembly. This helped immensely. At 154 hours and my 2nd condition inspection, I noticed about 1/16? of fore-aft play or (slack) and installed a 3rd isolation washer. I now have 220 hours on the aircraft and am watching it closely. My EWCG is 80.20? which is way forward, but built per the plans. I religiously taxi with the stick full aft and keep the weight off the nosegear to the best of my ability. It is hard to imagine the elastomers compressing that much. YMMV.

Greg Novotny
RV-14a N14ZP
Tacoma Narrows KTIW

I wonder if Van's has improved the elastomers so they will last longer, or if replacement every 200 hours or so is going to be the norm. Perhaps the way the elastomers work, they just need to wear out that soon.