Azuza wheel rims torque
Posted: Sat Oct 03, 2015 9:00 am
by SvingenB
The wheel rims on the Azuza wheels are two pieze bbolted with 3 bolts. Does anyone have any idea of the torque on these? They are not AN bolts?
Re: Azuza wheel rims torque
Posted: Fri Oct 09, 2015 10:06 am
by peter anson
Just had a look at a wheel and the bolts were SAE grade 5. Torques for a 5/16 bolt range between 9 and 22 ft lbs depending on surface coating. I’d be inclined to use the lower range, no more than 14 ft lb, because I think it would be possible to crush the wheel. I have never actually torqued the bolts. Just did them up tightish and guess what? It’s always been OK.
Peter Anson
Sonex 894
212 hours
Re: Azuza wheel rims torque
Posted: Fri Oct 09, 2015 11:34 am
by LarryEWaiex121
Tighten those bolts up pretty darn tight. Your going to be inflating those tires about 20 higher than the max pressure stamped on the side of the wheel. About 45-50 psi.
The only folks I’ve ever heard about breaking wheels were those using lower than normal tire pressure and minimal torque on the bolts.
As a side note, if your tires get below about 35lbs you run the real risk of moving the tire bead on the wheel during hard braking and then you get an almost instant flat when it rips the stem off the tube.
Tighten them up tight and run good solid tire pressure.
Larry
Re: Azuza wheel rims torque
Posted: Fri Oct 09, 2015 4:19 pm
by DCASonex
Cautionary note to anyone running the larger 5.00 x 5 tires. Do not inflate to 50 psi, way too much for the wheel with those tires. I find 25 psi works well with the larger tires.
David A
Re: Azuza wheel rims torque
Posted: Fri Oct 09, 2015 4:23 pm
by N111YX
Also, and this is mentioned many times elsewhere in the website, it’s best to get the AN equivalent bolts for the wheels. I have seen an Asuza wheel taken down for maintenance and one of the stock bolts was broken.
It’s cheap insurance…
Re: Azuza wheel rims torque
Posted: Fri Oct 09, 2015 5:27 pm
by peter anson
Tighten those bolts up pretty darn tight. Your going to be inflating those tires about 20 higher than the max pressure stamped on the side of the wheel. About 45-50 psi.
The only folks I’ve ever heard about breaking wheels were those using lower than normal tire pressure and minimal torque on the bolts.
As a side note, if your tires get below about 35lbs you run the real risk of moving the tire bead on the wheel during hard braking and then you get an almost instant flat when it rips the stem off the tube.
Tighten them up tight and run good solid tire pressure.
This is interesting Larry. I have never run my tires higher than the recommended pressure, and usually at only 30 psi. Have now done over 370 landings on both sealed and unsealed runways and never had any tire problems. My first set of tires are getting worn and will have to be replaced in a few months. I had a bit of a panic when I heard of another builder having punctures due to breaking cords in the tires from running low pressures so I ordered spare tires and tubes and pulled my wheels apart to inspect them. Everything was in perfect condition. I still have the spares.
Peter
Re: Azuza wheel rims torque
Posted: Sat Oct 10, 2015 8:51 am
by Msing48
I have had sevearal flats due to low tire pressure. One time the valve stem tore partially off but the others were from slices in the tube where the rim pinched the tube, probably from my less than stellar landings. I try to keep an absolute minimum of 35psi, but optimally 45psi.
Mike Singleton
Re: Azuza wheel rims torque
Posted: Sat Oct 10, 2015 9:15 am
by nwawingman
What is the reason for higher air pressure of 45 lbs? Is it to keep the tire from spinning on the rim? If that is the case could some type of tire dressing or sealant be used on the rim edge to help prevent this. I have noticed my valve stem getting pinched before due to low air pressure I think.
Re: Azuza wheel rims torque
Posted: Sat Oct 10, 2015 12:22 pm
by Bryan Cotton
Great idea Kip. Do you have part numbers? I have the Sonex brakes. I wonder what grade hardware they are? They seem better than the Azuza bolts.
Re: Azuza wheel rims torque/broken bolt
Posted: Sun Jun 12, 2022 8:53 pm
by lpaaruule
My right brake was grabbing after my last flight, and I found that one of the 3 bolts that go though the wheel and hold the Aerobrake rotor had broken flush with the wheel. I guess the nut is somewhere on the runway.
On contacted Sonex tech support to get a replacement, and maybe replace all the bolts.
I noticed that the pucks are worn at an angle, indicating that the rotor is flexing during braking. I’m guessing this flexing may have contributed to the bolt fatigue.
The rotor side of the bolt was really chewing up the pucks. I’m lucky it didn’t lock up.
I don’t think that this is something that can be inspected to prevent failure, but I’ll see what Kerry says.
Re: Azuza wheel rims torque
Posted: Sun Jun 12, 2022 9:18 pm
by N111YX
That’s not the first Asuza bolt to break. It’s basicallly an un-issued service bulletin to replace Asuza bolts with AN bolts.
These wheels are made for go carts. They work but the bolts are the weakest link.
Re: Azuza wheel rims torque
Posted: Mon Jun 13, 2022 12:14 am
by WaiexN143NM
hi all,
yes good idea to replace the azusa bolts w an hardware if using the stock brakes. as for the sonex hyd brakes they come with the flush countersunk hex bolts. paul are both of your sides (left and rt wheels) doing this wear pattern?
anyone else experience this. ? it almost seems like the wheel has got some play to the axel.
are the bearing races seated down fully?
do you think that one of the bolts came loose a little ? heavy braking and the nylon lock nut melted a little
and the bolt vibrated a little loose? maybe we should be using all metal locking nuts.
keep us posted!
WaiexN143NM
Michael
Re: Azuza wheel rims torque
Posted: Mon Jun 13, 2022 8:30 am
by lpaaruule
Tech support says it’s unlikely that the disc is flexing, and said to make sure the pucks land squarely on the disc, and the caliper can float a little on the clevis pin during reassembly. I take this to mean, make sure it isn’t binding.
I’m almost 100% sure that both sides had the brake pucks wearing at an angle. I’ll double check that when I get back out to the hanger, but that may be a while. Also, the wear angle of the pucks both slope to the outer edge of the disc, which is why I suspected disc flex vs caliper binding.
Other than that, I got the part number for the bolt so I can get a replacement.
Re: Azuza wheel rims torque
Posted: Mon Jun 13, 2022 9:23 am
by WesRagle
Hi Guys,
lpaaruule wrote:I’m almost 100% sure that both sides had the brake pucks wearing at an angle. I’ll double check that when I get back out to the hanger, but that may be a while. Also, the wear angle of the pucks both slope to the outer edge of the disc, which is why I suspected disc flex vs caliper binding.
I’m just going to throw this out there for consideration.
On previous planes I’ve owned, while doing wheel maintenance, I always tightened the axle nut until there was moderate rolling resistance on the wheel and then backed off a little. I had been doing the same with the Onex. Now, I had always had a problem with my Sonex hydraulic brakes. I needed to pump them up after each landing before they would work and I didn’t understand why.
When I recently changed my tires I decided to torque the axle nut down really tight and then back off. I no longer have to pump my brakes on landing. Could have been that while tightening the nut in the past the puck was partially extended and I never tightened the nut enough to properly seat the puck and had been flying around with a slightly loose wheel. This might cause the pucks to wear at an angle.
YMMV,
Wes
Re: Azuza wheel rims torque
Posted: Mon Jun 13, 2022 9:57 am
by WaiexN143NM
hi all,
one thing i forgot about my install with the sonex hyd brakes, i installed a square backing plate, from tracy obrien,
that i welded to the axle. this gives me 3 bolts holding the red brake body to axle , instead of the small one tab.
there is no float or flex, the pucks wear evenly on my discs.
WaiexN143NM
Michael.
Re: Azuza wheel rims torque
Posted: Tue Jul 05, 2022 10:35 am
by lpaaruule
Finally got back from an epic vacation (in my Jeep, so I won’t go into detail), and installed the new brake parts. I noticed that it took quite a bit more torque to remove the bolts from the side with the broken bolt than the other side. I’m guessing that I might have overtorqued the wheel with the broken bolt. These are course thread, and I might have used the fine thread torque. On the other hand, the side with the broken bolt had much less tread on the tire than the other side, so maybe it was a heating issue due to the right side being used more.
I replaced all the wheel bolts and nuts, and torqued the new ones to 45 in-lbs in hope of putting the least amount of stress on them as I can do safely. I also over tightened the axle nut, then backed it off to make sure that everything was seated correctly.
I did some taxiing, and a short flight, and the breaks are working really well again. I’ll have to think about whether I’m going to replace these as a regular PM item or not.