TravelVeteran Posted November 2, 2020 Report Posted November 2, 2020 https://www.univair.com/ercoupe/view-all/415-33115-ercoupe-shock-pad/ will these work? 1965 MOONEY M-20C MARK 21 N5673Q SN 3035 TYPE CERT 2A3 PROD CERT 201 Quote
TravelVeteran Posted November 3, 2020 Author Report Posted November 3, 2020 would you mind linking me to the best options? i found some on spruce but they only have a "5 year shelf life" ... not sure if thats long enough. someone told me to find 10 year shock pads. Quote
TravelVeteran Posted November 3, 2020 Author Report Posted November 3, 2020 On 11/3/2020 at 1:04 AM, bluehighwayflyer said: Unfortunately (due to their price), this is what you need. Hopefully your Mooney has already been modified to accept them. If it hasn’t it will cost you even more. How many shock discs do you currently have on your nose and your mains? https://www.aircraftspruce.com/catalog/lgpages/lord-m20-mooney.php Expand i believe 3 on nose, 4 on mains. are those the only option? Quote
carusoam Posted November 3, 2020 Report Posted November 3, 2020 TV, There is only one design... since Firestone left the business.... There is only one rubber compound... As far as shelf life goes... rubber cross-linking continues on eternally... but doesn’t change enough for this application... UV light is pretty tough on them... Oxidation never helps... Both challenges are surface issues... What wears out the donuts... use. What wears them out faster... heavy weight compressing them 24/7... Find the right ones, get the best price... the Lord ones are about $100 each... Use caution with some warehouse stores... make sure you get a delivery date with that... There was one re-seller that would hold orders back until they got a volume discount prior to placing their order... PP thoughts only, not a mechanic... Best regards, -a- Quote
Raptor05121 Posted November 3, 2020 Report Posted November 3, 2020 On 11/3/2020 at 1:07 AM, TravelVeteran said: i believe 3 on nose, 4 on mains. are those the only option? Expand Earlier models had thinner pads, but more of them. The 3 nose/4 main is the latest. There are some planes out there using the old system, and conversion adds more cost to it. Quote
carusoam Posted November 3, 2020 Report Posted November 3, 2020 On 11/3/2020 at 1:09 AM, Raptor05121 said: Earlier models had thinner pads, but more of them. The 3 nose/4 main is the latest. There are some planes out there using the old system, and conversion adds more cost to it. Expand This was the Firestone donuts... most have been replaced over the decades... Additional hardware is required to change to Lord donuts... Always give a good look at the tube at the center of the donuts... it can get really rusty without a lot of warning... Best regards, -a- 1 Quote
StevenL757 Posted November 3, 2020 Report Posted November 3, 2020 (edited) On 11/3/2020 at 1:07 AM, TravelVeteran said: i believe 3 on nose, 4 on mains. are those the only option? Expand Yes. @bluehighwayflyer gave you the correct and only part number for these. @TravelVeteran, be advised there is no specific “5 or 10 year shelf life” for these shock disks. They need to be tested/checked at every annual inspection, and will last long as you take care of them. Enemies of the disks (things that shorten their life) include, but are not limited to: Leaving the aircraft tied down outside Letting the aircraft sit for extended periods of time with greater than roughly half a load of fuel. This gradually compresses the disks over time Steve Edited November 3, 2020 by StevenL757 Additional content 1 Quote
RLCarter Posted November 3, 2020 Report Posted November 3, 2020 On 11/3/2020 at 12:59 AM, TravelVeteran said: would you mind linking me to the best options? Expand my apologies for such a short answer earlier, I was on my cell and was looking up the link and my reply got sent out before it was complete 1 Quote
Buckeyechuck Posted November 12, 2020 Report Posted November 12, 2020 On 11/3/2020 at 1:14 AM, StevenL757 said: Yes. @bluehighwayflyer gave you the correct and only part number for these. @TravelVeteran, be advised there is no specific “5 or 10 year shelf life” for these shock disks. They need to be tested/checked at every annual inspection, and will last long as you take care of them. Enemies of the disks (things that shorten their life) include, but are not limited to: Leaving the aircraft tied down outside Letting the aircraft sit for extended periods of time with greater than roughly half a load of fuel. This gradually compresses the disks over time Steve Expand So I have bladders in my C. I’ve always heard, keeping full tanks will keep them healthy. So I have healthy bladders and compress my shock donuts or have healthy shock donuts and bad bladders. Can’t win. 1 1 1 Quote
rbridges Posted November 12, 2020 Report Posted November 12, 2020 On 11/12/2020 at 12:31 AM, Buckeyechuck said: So I have bladders in my C. I’ve always heard, keeping full tanks will keep them healthy. So I have healthy bladders and compress my shock donuts or have healthy shock donuts and bad bladders. Can’t win. Expand One silver lining is that they tend to last longer in short bodies. 1 Quote
RobertGary1 Posted November 12, 2020 Report Posted November 12, 2020 On 11/12/2020 at 12:31 AM, Buckeyechuck said: So I have bladders in my C. I’ve always heard, keeping full tanks will keep them healthy. So I have healthy bladders and compress my shock donuts or have healthy shock donuts and bad bladders. Can’t win. Expand Ogh. I can’t imagine having to tanker fuel around. I rarely fly 6 hour legs and only then do I fill my tanks. Turns a sports car jnto a sluggish sedan. -Robert Quote
Ragsf15e Posted November 12, 2020 Report Posted November 12, 2020 On 11/12/2020 at 2:39 AM, RobertGary1 said: Ogh. I can’t imagine having to tanker fuel around. I rarely fly 6 hour legs and only then do I fill my tanks. Turns a sports car jnto a sluggish sedan. -Robert Expand Ha! Well I’ve heard keeping the original wet wing tanks relatively full keeps the sealant from drying out, so maybe you still have a choice between your shock discs and tankering fuel! Quote
tmo Posted November 12, 2020 Report Posted November 12, 2020 I guess one could raise the plane on jacks when hangared... Actually, my grandfather did just that to all of his cars, as he did not drive in the winter. 1 Quote
David Lloyd Posted November 12, 2020 Report Posted November 12, 2020 Years ago I read in the ABS magazine that only a cup of fuel was good enough to keep bladders from drying out. Quote
Parker_Woodruff Posted November 12, 2020 Report Posted November 12, 2020 On 11/3/2020 at 1:09 AM, carusoam said: TV, There is only one design... since Firestone left the business.... Best regards, -a- Expand Was Firestone really in the Mooney shock business? As an Indycar fan I'd be obligated to buy theirs...Or was theirs the white rubber wonders the early planes left the factory with? Quote
mike20papa Posted November 13, 2020 Report Posted November 13, 2020 The "up grade" to Lords is a lot of work. The original Firestones were jewels that the whole gear system was designed around. When you do the conversion - you will understand that the Lords are a "retro fit". Some would call it a "beat to fit/paint to match" $$ affair. Joe 1 Quote
carusoam Posted November 13, 2020 Report Posted November 13, 2020 Holy cow, Mike20P! You have pictured the holy grail! The Firestone’s were a set of 5 donuts in place of our current four... and the center tube was different dimensions... You also captured the rust on the center tube that can occur... Some planes have difficulty keeping that tube dry... and they may rust away... A reason to check the tube dimensions when changing donuts... Great pics! Thanks for sharing them... Best regards, -a- Quote
cliffy Posted November 15, 2020 Report Posted November 15, 2020 When Mooney made his single place Mooney Mite he actually used the rubber motor mounts from a large truck for the landing gear donuts. He kept that design but had to have larger donuts made for the first 4 place M20. Those were the Firestone donuts. Firestone supply died and a conversion to Lord mounts was put in place as we have now. Most suppliers run around $110 for each donut (sometimes on sale though). There is a guy in South Africa making new donuts and he was working on an approval for them at around 1/2 the price of Lord mounts. Search here to find him. Haven't heard about him in some time. He makes donuts for other airplanes as Mooney isn't the only small airplane with this design for landing gear shock absorption. 2 Quote
hammdo Posted November 15, 2020 Report Posted November 15, 2020 I linked to the ‘Gert’ thread - above... -Don 2 Quote
mike20papa Posted November 15, 2020 Report Posted November 15, 2020 Notice the two notches or relieved sections in the disk flange on the shock tower? .. The retro fit to Lords does not take this dimensional interference into consideration .. in simple terms.. Do all the work as shown in the drawings and the gear will NOT retract and lock. You have to then (after all the swearing & cursing) relieve clearance around the link at the pivot bolt( what I chose to do .. or else remove the biscuits and accomplish the notches in the shock tower base plate. Also, I didn't rebore the new shock towers to size because I was looking to exercise my drill press .. Joe '59 A model.. First photo shows the tool I devised to remove the shock tower retaining collar. It was not a simple swap out - either. 1 Quote
Tcraft938 Posted November 16, 2020 Report Posted November 16, 2020 On 11/13/2020 at 12:10 AM, mike20papa said: The "up grade" to Lords is a lot of work. The original Firestones were jewels that the whole gear system was designed around. When you do the conversion - you will understand that the Lords are a "retro fit". Some would call it a "beat to fit/paint to match" $$ affair. Joe Expand Great pics and info. What I want to know is where does one get the red tool/jig, or did you make it? It looks like it applies a lot of force and if done improperly plane and/or human are in for a world of hurt. Thanks Quote
carusoam Posted November 17, 2020 Report Posted November 17, 2020 Donut compression tools... There are a few suppliers around here.... Main landing gear can be done without the tool... Compressing the nose gear is a bit tougher... Buying new from Mooney can be prohibitively expensive.... Building your own hydraulic compression tool has been detailed around here somewhere... Best regards, -a- Quote
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