Questions on changing tires

[DaV8or]

I want to change the main tires on my M20F and also install the LASAR hubcaps I bought. My questions are, is it safe to jack the main gear up one at a time by putting a steel bar into the hollow tube in the "knee" of the landing gear and using a floor jack? Similarly, can you jack the nose gear up by inserting a steel bar in the tow bar hole and lifting with a floor jack? Lastly, do the wheels have to be rebalanced after the new tires and tubes are installed and where would I get that done?

Thanks for the help.

[MooneyMitch]

Dave.  For myself, I would not do that at all.  Use the correct jacking points and hydraulic jack stands.  If you have none available to you, please contact me via email.

[kerry]

I can't tell you if it's right or wrong but I've been doing it this way(steel bar w/ floor jack) for several years with no problems.  You only have to lift the tire an inch.  I don't see how it can put any stress on landing gear.  I have an A model which has no jack points.  For a gear retraction your suppose to put your back underneath the tip of the wing and lift it while squating up.  Then you have someone slide a 32" saw horse under the wing.  It's a lot easier to use that bar and I'm jacking it up a foot so I can get the saw horse under the wing.  Your bar needs to be long enough so that your jack is out far enough so that you have enough room to get your wheel off the axle.

[triple8s]

I have done that very thing before, when in a pinch, but I went through the outboad side of the gear tube. The reason is you cant get the wheel off with a rod in the main gear hole because the jack is in the way, and the longer the rod you use to gain clearance to remove the wheel the more folding pressure you will put on the gear. For this reason I removed the gear door and put the steel rod through and jacked from the outboard side as close as possible to the gear tube. (more trouble than it is worth) I now have the little jack points its much safer and when you arent using them for jacking the Mooney, they make great little tops!

[jbreda]

I would not put asymmetric forces on the geat that way.  The jack points are cheap.  LASAR has a set with the tiedowns which you can leave in place and they will always be there. 

FYI: I have a used pair of Meyers Hydraulic jacks in Boston area I may be willing to sell (extra pair).  If interested you can e-mail me at johnabreda@yahoo.com

John Breda

[danb35]

I don't really have a strong feeling about the jacking issue--I wouldn't think what you're suggesting is the best way to do it, but I also don't think it'd cause any harm.  Airplane wheels and tires aren't generally balanced, AFAIK--just make sure to line up the light part of the tire with the valve stem and you're generally good.

[DaV8or]

Quote: jbreda

I would not put asymmetric forces on the geat that way.  The jack points are cheap.  LASAR has a set with the tiedowns which you can leave in place and they will always be there. 

FYI: I have a used pair of Meyers Hydraulic jacks in Boston area I may be willing to sell (extra pair).  If interested you can e-mail me at johnabreda@yahoo.com

John Breda

[DaV8or]

Quote: danb35

Airplane wheels and tires aren't generally balanced, AFAIK--just make sure to line up the light part of the tire with the valve stem and you're generally good.

[Immelman]

Normally you don't need to have the tire/wheel balanced but note the red dot on the tire (if any) indicates the (heavy/light point -- sorry I forget which, look it up? and you either align that with the inner tube valve stem or put it 180 degrees opposite.

With that said, if a wheel needs balance, you might try taking it to a motorcycle shop. If you do get it balanced, I suggest making sure the tire/wheel hasn't been sitting with a stationary airplane on it as these can make them out of round (wait a couple hours and the flat spot will go away). Probably not a factor if you are putting a brand new tire on.

[MooneyMitch]

There is a set of jacks for sale in the MAPA LOG.  951 260-9118.  Bert Vos from CA.  Maybe?

[danb35]

Quote: DaV8or

The cheapest I've seen is $200 a jack plus shipping. I'm starting to think that changing your own tires is false economy. I can get it done at a MSC for lots less than $500.

[Shadrach]

A more creative solution is just to buy a set of inexpensive bottle jacks and make (or have fabricated) steel pedastools/supports. A descent bottle jack can be had for $50 or less as long as it does not say "airplane jack" on it, then you must multiply the price X 5 or more. Most bottle jacks have drillable bases so as to be easily mounted to a bracket or pedastool. You could even use wood if you really wanted to be cheap. 

 

[thinwing]

dave..before you jack up your bird like that..next time you are by ksac...why dont you borrow my jacks and while we are at it i will show you were the red dot is supposed to go when you balance the tire...kp couch

[thinwing]

also when you change your main tires out...that is the time to grease and check main bearings and you should know how much preload to place on the castellated axel nut...this is typical own annual stuff....new to you right???..kp couch

[Vref]

Quote: Shadrach

A more creative solution is just to buy a set of inexpensive bottle jacks and make (or have fabricated) steel pedastools/supports. A descent bottle jack can be had for $50 or less as long as it does not say "airplane jack" on it, then you must multiply the price X 5 or more. Most bottle jacks have drillable bases so as to be easily mounted to a bracket or pedastool. You could even use wood if you really wanted to be cheap. 

 

[Shadrach]

Quote: Vref

was covered in this thread:

http://mooneyspace.com/index.cfm?page=3&mainaction=posts&forumid=3&threadid=2852#post33733

would like to see how this thread evolves ...once helped to change a tire on a 737 but never on a mooney...

[Vref]

Thanks, though the effort was done because there are no cheap solutions in Europe for Mooney Jacks....to much money and carbon emissions to transport some metal over the pond...

[DaV8or]

Quote: Shadrach

A more creative solution is just to buy a set of inexpensive bottle jacks and make (or have fabricated) steel pedastools/supports. A descent bottle jack can be had for $50 or less as long as it does not say "airplane jack" on it, then you must multiply the price X 5 or more. Most bottle jacks have drillable bases so as to be easily mounted to a bracket or pedastool. You could even use wood if you really wanted to be cheap. 

 

[DaV8or]

Quote: triple8s

The reason is you cant get the wheel off with a rod in the main gear hole because the jack is in the way, and the longer the rod you use to gain clearance to remove the wheel the more folding pressure you will put on the gear. For this reason I removed the gear door and put the steel rod through and jacked from the outboard side as close as possible to the gear tube. (more trouble than it is worth)

[MooneyMitch]

Got any photos of that Jim?

[MooneyMitch]

Got any photos of that Jim?  I'm kind of a dummy and do much better with a picture.

[kerry]

For what its worth I would like to say jacking up the main wheel from the inside of the landing gear would have less force versus landing your plane and having one of your mains touch before the opposite main(with my piloting skills this never happens lol).  When your jacking up one of the mains 1 inch and pivoting on the 2 other tires there not that much weight.  I think there's a lot more force  when you land on one wheel.  Like I said before I've been doing this for years and I've seen no issues.  I think I'll investigate more because if there are contraindications I'll discontinue this method.

[Ron McBride]

Dave

I changed the tires on my F by usuing a 3/4" pipe or a 1". The pipe bent while doing it. I would not do it again this way. I put a 4x6 block under the gear when I did it. It was not a comfortable way to do it. Next time, I would do it by building a platform out of 2x4 and put a bottle jack on the platform to lift the plane up.

When the tire change is complete, you should have your gear swung.

Ron

[stevesm20b]

I had a flat main tire on my Mooney. I had a low wing aircraft jack, but it would not fit under the wing with a flat tire. I just used a bottle jack placed on a 2X6 on a cinder block, place under the jack point and it worked great. I don't think you would have a problem jacking the front up using a bar in the towbar tube. Think about what kind of load is on the front tire when you apply the brakes after landing.