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sdischer
08-21-2020, 07:50 PM
I replaced all four bungees about a year ago and thought they would settle down but they haven’t. The outside of my tires lean outward like it is in flight. Should I use something besides the recommended part number like a combination of tensions?

mike mcs repair
08-21-2020, 08:01 PM
Plane model???

Gear style/STC???

Bungee part numbers???

Number of bungies per side???

Lots more information needed!

Outside of tires lean outside?? ???? WTH???


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tempdoug
08-21-2020, 08:04 PM
empty weight?

sdischer
08-21-2020, 09:01 PM
Plane model???
J3

Gear style/STC???
Stock 1942
Bungee part numbers???



1174 Shock Cord 11/16" x 7-1/2"
M-222-005


Number of bungies per side???
2

Lots more information needed!
sorry my bad

Outside of tires lean outside?? ???? WTH???

probably a bad description but another way to say it is the struts/shock cords are completely retracted and they are not extending at all even with for fuel and my 200 pound butt.

50742


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tempdoug
08-21-2020, 09:48 PM
is this a certified j3, something dosent look right there, could you take one of the covers off and show a closer picture?

sdischer
08-21-2020, 09:52 PM
is this a certified j3, something dosent look right there, could you take one of the covers off and show a closer picture?
Yes it is a certified AC. Ill grab some photos tomorrow. It has 850s on it right now.

tempdoug
08-21-2020, 09:57 PM
1174s are the right cord for below like 8000 serial number, but after that they call for even a stronger cord, have you measured your struts to other j3s? never seen one sit like that, hmm. at the 8200 serial number break there different long shock struts above and below. u31382 vs u30562. maybe univair would tell you if a difference in length, i have no drawings.

sdischer
08-21-2020, 10:15 PM
1174s are the right cord for below like 8000 serial number, but after that they call for even a stronger cord, have you measured your struts to other j3s? never seen one sit like that, hmm. at the 8200 serial number break there different long shock struts above and below. u31382 vs u30562. maybe univair would tell you if a difference in length, i have no drawings.
This on is serial 7203. It didnt sit that way with the old cords, it sat normally. I have owned it thirty years. When i replaced them this time I stripped the pieces and repainted, cleaned up inside and greased and they operated smoothly before I installed the new cords. I even pranged it in a few times and they havent relaxed at all. Possibly they were mislabeled.

mike mcs repair
08-21-2020, 10:30 PM
This on is serial 7203. It didnt sit that way with the old cords, it sat normally. I have owned it thirty years. When i replaced them this time I stripped the pieces and repainted, cleaned up inside and greased and they operated smoothly before I installed the new cords. I even pranged it in a few times and they havent relaxed at all. Possibly they were mislabeled.

No.


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tempdoug
08-21-2020, 10:31 PM
isnt there some little leather stops in the shock struts? page 13 81232-13 http://www.eaglesport.org/documents/cub_parts_manual.pdf are they in there? (http://www.eaglesport.org/documents/cub_parts_manual.pdf)

tempdoug
08-21-2020, 10:41 PM
https://www.univair.com/content/PIP_SB0103.pdf

tempdoug
08-21-2020, 10:50 PM
https://www.supercub.org/forum/attachment.php?attachmentid=24287&d=1455743079&thumb=1Number 14

BC12D-4-85
08-21-2020, 11:03 PM
Make sure that bolt and stops are there. My PA-11 worked them hard.

Gary

wireweinie
08-21-2020, 11:17 PM
That pic looks almost like extended legs with standard shock struts.

Web

BC12D-4-85
08-22-2020, 12:16 AM
Or the struts are mechanically short for some reason.

Gary

Douten
08-22-2020, 07:35 AM
Are the bungees even on both sides of the ears? Are they locked on one end so they can't stretch? Just thinking.

mike mcs repair
08-22-2020, 09:49 AM
Make sure that bolt and stops are there. My PA-11 worked them hard.

Gary

Thats my guess whats missing


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bob turner
08-22-2020, 12:19 PM
After sixty years fooling with these things I just discovered there are several lengths for each part. There is a standard length that seems to cover 1946 J3 through the PA-18-95, and then there are weird varieties. I asked on the J3 forum but got no responses.

If your aircraft is experimental, I recommend a brand new set from ExpParts. Better than the originals, inexpensive. But you need to put the rubber bands on. If you are in SoCal, happy to help you do that.

If not experimental, Univair has equally high quality parts (you cannot tell the difference) for roughly twice the price.

I think your struts got swapped out when the new bungees were installed. A good Cub mechanic would never take a straight set and return the aircraft pigeon-toed.

But it is marginally possible that your struts were incorrect to start, and your old rubber bands were so weak it looked normal.

bob turner
08-22-2020, 04:30 PM
Went to the airport, took these shots, did four landings, came home. As soon as my stomach recovers, I am going back for six slow rolls.

Anyway, look for two different strut lengths, two different bungee lengths, and understand - I just became aware of all this in the last six months, when a bunch of spares arrived and two buddies noticed a problem on their J3s

bob turner
08-22-2020, 04:33 PM
Those wood sticks are parallel, and the upper holes are aligned even with the upper wood stick. Should have lined them up for a less distorted shot. You get the idea?

BC12D-4-85
08-22-2020, 05:14 PM
Univair's catalogs (https://www.univair.com/parts-catalogs/) show a variety of struts...pre and post WWII it seems, plus by S/N.

Gary

Steve Pierce
08-22-2020, 06:57 PM
After sixty years fooling with these things I just discovered there are several lengths for each part. There is a standard length that seems to cover 1946 J3 through the PA-18-95, and then there are weird varieties. I asked on the J3 forum but got no responses.

If your aircraft is experimental, I recommend a brand new set from ExpParts. Better than the originals, inexpensive. But you need to put the rubber bands on. If you are in SoCal, happy to help you do that.

If not experimental, Univair has equally high quality parts (you cannot tell the difference) for roughly twice the price.

I think your struts got swapped out when the new bungees were installed. A good Cub mechanic would never take a straight set and return the aircraft pigeon-toed.

But it is marginally possible that your struts were incorrect to start, and your old rubber bands were so weak it looked normal.
Did he fix the issues I posted about in this post? https://www.supercub.org/forum/showthread.php?50611-Experimental-Parts

There are 2 different J3 gear depending on serial number. The differ in attachment bolt size and shock strut tube wall thickness.

Steve Pierce
08-22-2020, 06:59 PM
pictured gear does not look correct. Since it was correct prior to the new bungees do you think the shock strut could have been assembled incorrectly?

tempdoug
08-22-2020, 10:08 PM
maybe we will hear the rest of the story, maybe not. the little leather bumper stops do you make them bob?

BC12D-4-85
08-23-2020, 01:50 AM
Hey look...it's just a Cub trying to become a Champ with oleo gear. Nothing wrong with that transformation today.

Gary

bob turner
08-23-2020, 11:13 AM
Len makes the bumpers for us.

The lack of a bumper would mean at most a 1/8" difference. Missing the hole in the slider and leaving out the bumper could not account for this much difference.

All of these have AN-6 bolt holes. Some have PA-11 ears.

The OP has the wrong length struts.

mvivion
08-23-2020, 12:25 PM
Okay, if nobody else is going there.....I may as well.

In fact, there seem to be a few folks on here whose bungees are too tight.....

MTV

bob turner
08-23-2020, 12:33 PM
Were you here when they did the PA-11 blue throttle balls?

mvivion
08-23-2020, 03:11 PM
Were you here when they did the PA-11 blue throttle balls?

Uh, yup.....

MTV

RVBottomly
08-23-2020, 06:07 PM
pictured gear does not look correct. Since it was correct prior to the new bungees do you think the shock strut could have been assembled incorrectly?

That's what I was thinking too. Is the slider even in there? If it is, it shouldn't matter how tight the bungees are--yes it would matter on how the suspension felt, but the gear wouldn't be at that weird angle.

BC12D-4-85
08-23-2020, 06:32 PM
This kind of speculation should be reserved for January when things are slow.

Gary

bob turner
08-23-2020, 08:01 PM
Things are slow. Even if you leave the leather bumper out and miss the slider with your bolt, it wouldn’t bring the gear in that far. I took a shortie apart this afternoon, and it wouldn’t collapse much further, because the ears hit.

The difference between the shorties and the good struts is a full inch!

We had a Cub come to town with struts that looked like the OPs. A new set was an inexpensive cure.

sdischer
08-23-2020, 09:07 PM
I don't remember seeing any leather bumpers so I suspect they are gone. Here are some photos with the boots removed.



50772
50773

And here is is with the old shock cords, 8.00 tires, and all the same strut pieces and the tires are straight up and down, not canted in at the bottom.

50774

Steve Pierce
08-23-2020, 09:35 PM
Looks like your shock struts have been repaired/modified. Maybe your old shock cords were sagging and allowed the wheels to be perpendicular to the ground?

RVBottomly
08-23-2020, 09:50 PM
Slow here, too. I was trying to look closely at the before and after photos. It almost looks like a sleeve was put over the original lower shock strut. It's hard to tell, but the original strut looks narrower than the current one.

Did someone splice a sleeve on it and maybe shortened it a little?

sdischer
08-23-2020, 10:06 PM
No metal work has been done on the struts in over 30 years so no. I only stripped them, epoxy primed and repainted when I installed the bungees last year. That welding work was done before I bought it 30+ years ago. It is possible the old cords were stretched enough to make everything fit correctly over time. Not sure what to do at this point other then take measurements and try and compare to another similar year Cub.

Question: When sitting on the ground, unloaded, are the struts and cords typically fully compressed? If so, then clearly mine are wrong.

RVBottomly
08-23-2020, 10:47 PM
Question: When sitting on the ground, unloaded, are the struts and cords typically fully compressed? If so, then clearly mine are wrong.

Looking at online images of them in flight, and thus fully compressed, most look of them look like the wheels are close to vertical. I don't know enough about J-3s, but my project, a Wag 2+2, uses the same design. Fully compressed the wheels are close to vertical, just slightly canted.

BC12D-4-85
08-23-2020, 10:50 PM
My former PA-11 never extended the similar struts unless moving over uneven terrain. The wheels were close to vertical.

Gary

bob turner
08-24-2020, 01:18 AM
You cannot use these on a certificated aircraft, but they are so inexpensive that you could buy one just to look at it and compare. I highly recommend that experiment. Costs about what a good dinner for two with wine costs.

https://expparts.com/products/piper-j-3-style-shock-strut-assy

Even when mine get so old that one of them “necks” they are still potent enough to keep the shock struts fully closed when sitting empty.

Steve Pierce
08-24-2020, 06:39 AM
You cannot use these on a certificated aircraft, but they are so inexpensive that you could buy one just to look at it and compare. I highly recommend that experiment. Costs about what a good dinner for two with wine costs.

https://expparts.com/products/piper-j-3-style-shock-strut-assy

Even when mine get so old that one of them “necks” they are still potent enough to keep the shock struts fully closed when sitting empty.
I wouldn't recomend EXPParts for a static display. for reason stated in the link in my previous post. When I called the owner aout alignment issues his responce was they were experimental like that was an excuse for misaligned parts.

wireweinie
08-24-2020, 07:09 AM
I wouldn't recomend EXPParts for a static display. for reason stated in the link in my previous post. When I called the owner aout alignment issues his responce was they were experimental like that was an excuse for misaligned parts.

That subject of 'but it's experimental', alone, would make a great thread, but it might get me in trouble.

Web

Steve Pierce
08-24-2020, 07:27 AM
That subject of 'but it's experimental', alone, would make a great thread, but it might get me in trouble.

Web

Ha, I could tell you a pretty long drawn out story about the return of parts and him not crediting my customer etc. He didn't realize I took a picture of the open box on the scales when he tried to say I didn't return everything. Needless to say I think he is a POS.

Steve Pierce
08-24-2020, 07:34 AM
I have a strut for the early and the later J3, both 28 1/4" center to center on the bolt holes. The early one is considerably lighter. One pictured came of my wall of shame and has a bend to it that was straightened to get another Cub off the runway.
50876
50777

sdischer
08-24-2020, 07:22 PM
Thanks for the measurement, I will grab a tape tomorrow and measure mine.

PA-22/20-160
08-24-2020, 07:48 PM
Ha, I could tell you a pretty long drawn out story about the return of parts and him not crediting my customer etc. He didn't realize I took a picture of the open box on the scales when he tried to say I didn't return everything. Needless to say I think he is a POS.
I don’t know if great minds think alike or not but I’ve got the same opinion.

Steve Pierce
08-24-2020, 08:18 PM
I don’t know if great minds think alike or not but I’ve got the same opinion.

Good to know it isn't just me.

What is funny is through some investigating I found out he was one class behind me in the same high school.

sdischer
09-01-2020, 08:55 AM
Went to the airport, took these shots, did four landings, came home. As soon as my stomach recovers, I am going back for six slow rolls.

Anyway, look for two different strut lengths, two different bungee lengths, and understand - I just became aware of all this in the last six months, when a bunch of spares arrived and two buddies noticed a problem on their J3s

I took some actual measurements of my strut length versus what they should be to get the tires plumb up and down. I believe my struts are 1 5/8 inches too short. Based on the struts you have there is that the approximate difference in length between short and long struts about 1 5/8? Is the length difference all in the lower piece or will I have to replace all four parts of the struts?

bob turner
09-01-2020, 11:35 AM
One inch difference. Not a precision measurement. Replace everything - I re-use new bungees, but getting them off safely requires a special tool and great care. Not counting bolts and leather bumpers, two parts per side.

sdischer
09-01-2020, 04:28 PM
One inch difference. Not a precision measurement. Replace everything - I re-use new bungees, but getting them off safely requires a special tool and great care. Not counting bolts and leather bumpers, two parts per side.

does anyone know if the serial numbers prior to 7xxx had the long struts or the short struts?

BC12D-4-85
09-01-2020, 06:32 PM
Call Univair they sell both I believe. Catalog for J-3 (https://www.univair.com/content/partcatalog/J3PM-flipbook/mobile/index.html#p=21)

Gary

cubdriver2
09-01-2020, 07:06 PM
https://hosting.photobucket.com/albums/yy21/cubdriver2/cubdriver2010/.highres/397_zpsdcliuoui.jpg (https://app.photobucket.com/u/cubdriver2/a/cefc6999-9e23-4059-b465-2e029f2bcf2a/p/ff288882-afd6-4232-97c8-91029aae5ccb)

They come off and go on easy with a couple ratchet straps

Glenn