C.J. Posted September 22 Report Share Posted September 22 Looking for anyone with long term experience with main wheel inner tubes with a 70* degree valve stem. Was losing 2 pounds of pressure per week on my existing tubes. Servicing them was annoying given the valve stem is pressing against the wheel so I elected to get two Aero-Classic 6.00x6 GL-60877B tubes with the TR-87 70-degree valve stem. I checked with my mechanic confirming p/n prior to ordering. Now, without looking at them, he's saying they won't work. Don't remember exactly his reason, but IIRC it's the way the hole is drilled through the wheel not being able to accommodate the 70-degree bend. Found an old thread from 12/18/2020 prior to ordering the tubes - pictures below of a 1964 E before and after. @takair experience seems positive re: 70-degree stems, so what am I missing here? Is there a significant difference between the MLG wheels on my 1965 C versus a 1964 E? I just want a tube that doesn't leak and when service is needed, I'd like it to be easier to do. Thanks in advance. Quote Link to comment Share on other sites More sharing options...
Skates97 Posted September 22 Report Share Posted September 22 I'm not sure about the 70 degree stem, these 90 degree stems are what I have in mine. A bit pricier than the 70 degree... https://www.aircraftspruce.com/catalog/lgpages/gy_tire66.php Quote Link to comment Share on other sites More sharing options...
C.J. Posted September 22 Author Report Share Posted September 22 57 minutes ago, Skates97 said: A bit pricier than the 70 degree... OK, so $259 versus $103. @Skates97 You have a real flair for understatement. So why did you choose to go against the MS SOP of striving to be a ch**p bas*%#d or was there not a less expensive alternative at the time? Quote Link to comment Share on other sites More sharing options...
takair Posted September 22 Report Share Posted September 22 It is super frustrating that I can’t seem to find any clear combination of cross reference guides that would lead one to the right tube. When I bought the 70deg tubes, I was not 100% sure it would work, but could not find anything restricting them or, for that matter, anything that said you must use a straight stem. I would be curious if your mechanic has found a specific reference that requires a straight stem….I really have looked and can’t find that…. Knock on wood, I am still happy with the 70 deg, much easier to service than the straight stem or 90 stem on the 6” wheels. I use 90 on the nose wheel. I wish I could tell you which stem the 65 uses….I looked again and it reminded me of the difficulty I’ve previously had. If you have to bend a straight stem to service it, you may be a candidate for the 70. 1 1 Quote Link to comment Share on other sites More sharing options...
C.J. Posted September 23 Author Report Share Posted September 23 @takair I'll have to ask my mechanic tomorrow if he had a specific reference re: straight stems for the MLG wheels. I'll update the thread if he does. He did state the 90-degree stem for the nose wheel I ordered/received would work. Thanks for the long term (near 4 year) PIREP for the 70-degree stems. Quote Link to comment Share on other sites More sharing options...
PT20J Posted September 23 Report Share Posted September 23 I think what you are looking for is the valve stem options that work with the type wheel you have. For instance, Michelin's Airstop tubes are available in 5.00x5 with a TR-67 bent 90 deg. valve. The 40-87 nose wheel on my M20J has a grommet to accept this metal valve stem. The Michelin 6.00x6 tube uses a TR-20 straight rubber valve stem and the 40-56 main wheel has a plain hole to accept this valve stem. You might need to call Parker Hannifin tech rep to find out what valve stems are compatible with your wheels and then you can look for tubes that have those stems. EDIT: I tried to find the TR valve stem specs but they are maintained by the Tire and Rim Association of Akron, OH and only available for purchase. I'm sure that for a mere $194 you will learn more than you want to know about aircraft tire, tube and wheel specifications Quote Link to comment Share on other sites More sharing options...
Skates97 Posted September 23 Report Share Posted September 23 20 hours ago, C.J. said: OK, so $259 versus $103. @Skates97 You have a real flair for understatement. So why did you choose to go against the MS SOP of striving to be a ch**p bas*%#d or was there not a less expensive alternative at the time? I proudly lived in the CB club for a long time after getting the plane, but I believe my membership card was taken away around the time I put the GFC500 in and my wife decided the plane had to be painted. And at the time that was the only 90° stem tube that could be found. 2 Quote Link to comment Share on other sites More sharing options...
Hank Posted October 4 Report Share Posted October 4 This is what I put on as new main tire and tube. Shockingly, this was Jan 2018. Doing fine! Quote Link to comment Share on other sites More sharing options...
C.J. Posted October 4 Author Report Share Posted October 4 On 9/22/2024 at 6:54 PM, takair said: It is super frustrating that I can’t seem to find any clear combination of cross reference guides that would lead one to the right tube. When I bought the 70deg tubes, I was not 100% sure it would work, but could not find anything restricting them or, for that matter, anything that said you must use a straight stem. I would be curious if your mechanic has found a specific reference that requires a straight stem….I really have looked and can’t find that…. Knock on wood, I am still happy with the 70 deg, much easier to service than the straight stem or 90 stem on the 6” wheels. I use 90 on the nose wheel. I wish I could tell you which stem the 65 uses….I looked again and it reminded me of the difficulty I’ve previously had. If you have to bend a straight stem to service it, you may be a candidate for the 70. My mechanic had no specific reference regarding the straight stem being required. He concluded the TR87 70* valve stem would work solely based on your photos and trouble-free experience thus far. I looked at the TCDS http://www.accelerationtech.com/Photos/Mooney/TypeCert/FAA-Type-Cert-Mooney-2A3.pdf pages 13/53 and 20/53, item 202(a) which specified regular tubes. I would assume that means straight stems. I e-mailed Frank Crawford at Mooney to confirm if your 64E and my 65C left the factory with the 40-24 wheel assembly, of the 3 different assemblies listed in the TCDS; they did. I called Parker Hannifin (thanks @PT20J for that suggestion) to ask what inner-tube valve stems were compatible with the 40-24 and their data only specified a straight stem. BTW they don't manufacture the 40-24 anymore and it's listed as "obsolete". I agree that it's frustrating there's no reference available regarding this valve stem. Evidently, it's word of mouth and MooneySpace posts that will guide us for now. 2 Quote Link to comment Share on other sites More sharing options...
C.J. Posted October 4 Author Report Share Posted October 4 1 hour ago, Hank said: This is what I put on as new main tire and tube. Shockingly, this was Jan 2018. Doing fine! Hank, Thank you for your "shocking" PIREP - much appreciated. Quote Link to comment Share on other sites More sharing options...
Hank Posted October 4 Report Share Posted October 4 43 minutes ago, C.J. said: Hank, Thank you for your "shocking" PIREP - much appreciated. You're welcome, and forewarned--time flies faster than your Mooney!! Quote Link to comment Share on other sites More sharing options...
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