Oscar Avalle Posted February 3, 2014 Report Posted February 3, 2014 I know this must have been answered before, but I just could not find the threat. I was wondering: a. How can you find out if your rubber donuts oon our landing gear need to be replaced, b. Who sells them... I own a M20C 1970. Once again, sorry if I am asking a question that has been answered before...and thanks in advance for the response. Oscar Quote
rbridges Posted February 3, 2014 Report Posted February 3, 2014 Rule of thumb on short bodies is around 10 years. I would imagine any MSC would sell them, but some of the guys here may know where to find them a little cheaper. Quote
Marauder Posted February 3, 2014 Report Posted February 3, 2014 Oscar -- mine last 22 years. The only reason I changed them was that I was seeing the electrical squat switch not activating on occasion. I'm sure Maxwell, Weber, Lasar and most of the Service Centers will sell them. I have seen prices from the low $90s USD to $105 USD per each. Quote
jasonwojo Posted February 3, 2014 Report Posted February 3, 2014 Not to be short, but your maintenance manual will tell you everything you need to know. They are inspected on-condition and have a measurement. Please do not change them because of time. Every airplane has a different situation and should be treated that way for inspections. Follow the manual (your mechanic should be doing this annualy) and don't fix what ain't broke... http://www.swta.net/monthlyspecial.html 1 Quote
jrwilson Posted February 3, 2014 Report Posted February 3, 2014 Mooney just put out a service bulletin about them... Quote
N201MKTurbo Posted February 3, 2014 Report Posted February 3, 2014 Basically, with the plane up on jacks there should be no clearance on the top of the doughnuts. Temperature has a big impact on this. If you just brought the plane in from freezing cold and jacked it up it will probably fail. When it warms up they will expand and meet specs. But it is good to have your landing gear work when it is cold. It just means you will have to make a choice between economy or functionality. Quote
Marauder Posted February 3, 2014 Report Posted February 3, 2014 Basically, with the plane up on jacks there should be no clearance on the top of the doughnuts. Temperature has a big impact on this. If you just brought the plane in from freezing cold and jacked it up it will probably fail. When it warms up they will expand and meet specs. But it is good to have your landing gear work when it is cold. It just means you will have to make a choice between economy or functionality. I flew for years in Buffalo and on really cold days, the gear wouldn't retract. I ended up installing the Mooney kit with the red button override. It was only when it began having a hard time activating the switch on warm days that I began looking at replace them. Quote
63C Posted February 3, 2014 Report Posted February 3, 2014 I know this must have been answered before, but I just could not find the threat. I was wondering: a. How can you find out if your rubber donuts oon our landing gear need to be replaced, b. Who sells them... I own a M20C 1970. Once again, sorry if I am asking a question that has been answered before...and thanks in advance for the response. Oscar We got everything we needed from Don Maxwell. He was very helpful with how too's and sketches / diagrams. Quote
Dcflyn Posted February 3, 2014 Report Posted February 3, 2014 We just replaced ours on our 1966 E model. I don't know when they were last replaced (long time!!). When the plane was put on jacks, all three gear had "play"-- I could push the gear aft about 1/2" or so with my feet causing the shock disks to move up their column. New ones need to actually be pre-compressed to fit in their assembly. No more play. We are just finishing an entire undercarriage rebuild: http://n2690w.blogspot.com/ Quote
jetdriven Posted February 3, 2014 Report Posted February 3, 2014 We just replaced ours on our 1966 E model. I don't know when they were last replaced (long time!!). When the plane was put on jacks, all three gear had "play"-- I could push the gear aft about 1/2" or so with my feet causing the shock disks to move up their column. New ones need to actually be pre-compressed to fit in their assembly. No more play. We are just finishing an entire undercarriage rebuild: http://n2690w.blogspot.com/ Now thats some great info. We are about to do the same thing, tear all the gear out and totally go all through it. How many bushings did you replace? 1 Quote
scottfromiowa Posted February 4, 2014 Report Posted February 4, 2014 Now thats some great info. We are about to do the same thing, tear all the gear out and totally go all through it. How many bushings did you replace? +1! Awesome blog. Well done. Beautiful work. VERY educational. 1 Quote
Guest Posted February 4, 2014 Report Posted February 4, 2014 The shock discs have a date code on them so you should be able to see when they were produced. From experience, they may still pass the compressed height and be "serviceable" but they are stiff as rocks. New ones really improve the ride and landing. Clarence Quote
BigTex Posted February 4, 2014 Report Posted February 4, 2014 These shock discs are a tricky thing. You have them replaced and you can't believe how much better the plane rides. Then over time (years) they start getting harder and because it's over an extended period of time, you get accustomed to the ride. So you’ll never really notice a difference. When I purchased my plane, the prior owner was bragging on the condition of the discs. But when Don Maxwell took the plane out for its pre-buy flight, he came back saying it road like a tank. He said he was completely worn out by the time he got to the end of the runway. The prior owner was shocked… His only comment was, “they seemed to ride good to me.” In reality unless you’re in multiple Mooney’s you don’t have any comparison to what it “should” feel like. So because of this reason, timed replacements might be a better approach. Or at least have the discs removed at predetermined intervals to inspect the hardware holding the discs. When mine were replaced, the center post was completely rusted up and had to be replaced. 1 Quote
Dcflyn Posted February 5, 2014 Report Posted February 5, 2014 Now thats some great info. We are about to do the same thing, tear all the gear out and totally go all through it. How many bushings did you replace? We replaced all of the discs. In my mind, they're like batteries--better not replace some...particularly after all the work it takes to get to them and re-assemble. I highly recommend the Full Monty. In this case that would be stripping (blasting) the trusses clean, etch priming and then painting. It's silly how great it all looks--like a freshly built race car. But it's a lot of work! If I were to charge for the the undercarriage rebuild...$7500? Sent from my iPad using Tapatalk 1 Quote
isaacpr7 Posted February 5, 2014 Report Posted February 5, 2014 Ebay has them as well: http://www.ebay.com/itm/261252017115?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT 1 Quote
N201MKTurbo Posted February 5, 2014 Report Posted February 5, 2014 I did my gear about 8 years ago after Wilmar completely ruined the paint on the gear and the wheel well doing a tank reseal. It took about 40 hours of my time when it was all done. I did the wheel wells also. It sure improves the look of the plane when its done! Quote
Oscar Avalle Posted February 20, 2014 Author Report Posted February 20, 2014 This is how mine look now...any suggestions? Quote
Hank Posted February 20, 2014 Report Posted February 20, 2014 Oscar, Can't tell much by looking other than that they are apparently in good shape. There are measurements and a wiggle test for the top plate in the Service Manual. I just replaced mine in December, next time I'm at the plane [4 states away], I'll try to remember to take a picture. 1 Quote
carusoam Posted February 20, 2014 Report Posted February 20, 2014 I believe the only thing you could tell by a picture would be.. (1) excessive UV cracking. (2) the original design vs. modern design. Get a copy of the procedure. (Somebody had it posted, somewhere?) Best regards, -a- Quote
isaacpr7 Posted February 21, 2014 Report Posted February 21, 2014 You can find them on ebay if they need to be replaced. http://www.ebay.com/itm/261252017115?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649 Quote
kortopates Posted February 21, 2014 Report Posted February 21, 2014 Before buying them on ebay I'd suggest finding out what manufacturing date is on them. Old ones may not be such a great bargain. SWTA has had the best prices on the Lord disk. Quote
Sven Posted February 25, 2014 Report Posted February 25, 2014 This will show you the difference between old and new. http://mooneyspace.com/gallery/image/29409-/ 1 Quote
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