More trailer tire/wheel issues

On Friday, July 19, 2019 at 9:45:22 AM UTC-5, AS wrote:
On Friday, July 19, 2019 at 9:11:01 AM UTC-4, Nick Kennedy wrote:
Clay
You should have your bearings/ brakes checked out by a mechanic if you can't do it yourself.
Getting hot like you describe is not right.
Your not going to get very far with them heating up on a flat short drive.

I cannot confirm any of these described design deficiencies! My ~2012 vintage Cobra dual-axle trainer got moved across the US from SC to NM now four times - 1,600 miles each way - plus once to CO and back over some pretty punishing road surfaces. I installed a TPM system and keep an eye on the pressure and temperature of each wheel. Even during the long descent on I-70 west of Denver or while doing the 'Million Dollar Hwy' did the tire temperature not increase notably. I always check the hubs during gas stops and never burnt my finger.
The only thing I need to change now is the damper in the over-running brake, which seems to have gotten weak.
Please note that these trailers in Germany are subject to a state inspection every two years, where the brake and light system is checked, so regular maintenance is advised and generally accepted for the sake of keeping them safe.
The argument 'they don't use large pick-ups and SUVs over there, so we don't need brakes on our trailers here' is laughable! Once the towing vehicle is no longer perfectly in line with the trailer, the trailer will try to pass you - no matter what you are sitting in. The 'Auflaufbremse' or overrunning brake system is designed to keep the trailer behind the towing vehicle longer.

Uli
'AS'

I'm with Uli (AS). Knocking German enschineering is just not right, you hear that, Chip? You all should learn German anyway, would help when you study our "Auflaufbremse".
Herb, J7, flying and trailering in Tscherman Enschineered machines.

I've trailered my 1992 Cobra back and forth myriad times from NJ to Hobbs, Uvalde, Nephi, Cordele, TSA, etc. Most of the time everything is fine. The hubs are barely warm and everything works right.

But once in a while, from when the trailer was a few years old, a hard stop (not a locking-the-wheels, screeching-tires panic stop but just when someone cuts in front and you have to brake suddenly), the surge brake locks up and won't release. And with no backup cam, I can't see it. I just know to pull over and check right away. And now I watch the TPMS: the temperature rise seems to give me a heads up that it's happening.

I'm a mechanical engineer originally. I've been doing brake work for almost 50 years on my vehicles. I worked for 10 years for a company that made OEM and aftermarket brake parts. IMO, there's some vulnerability in the Al-Ko system that--when triggered--causes bad things to happen. As I detailed before, I've tried nearly everything this time. It locked up on the way back from TSA/Dallas last summer so I did a lot of maintenance/adjustment/replacement then and thought I had it fixed. And apparently I did--for a while. But on the way back from Columbus, OH last month (after the Stds. were postponed), I had to brake hard. I pulled over a few miles later and, sure enough, same problem. I just disconnected the brake system then to get home (I've had a lot of practice). More work after that. Last week on the way to and from Blairstown, the same problem. I'm running out of things to do.

There's a problem. I'm sure something is out of adjustment or alignment or something somewhere. And when that happens, disaster. As much as I love [most] German engineering, I shouldn't have to ship the trailer back to Germany to get it to work right!

Chip Bearden

Chip, if it started after Dallas perhaps a bullet from the "Who shot JB?" incident got lodged in the brakes.
Jim

On Friday, July 19, 2019 at 7:10:41 PM UTC-4, wrote:
I've trailered my 1992 Cobra back and forth myriad times from NJ to Hobbs, Uvalde, Nephi, Cordele, TSA, etc. Most of the time everything is fine. The hubs are barely warm and everything works right.

But once in a while, from when the trailer was a few years old, a hard stop (not a locking-the-wheels, screeching-tires panic stop but just when someone cuts in front and you have to brake suddenly), the surge brake locks up and won't release. And with no backup cam, I can't see it. I just know to pull over and check right away. And now I watch the TPMS: the temperature rise seems to give me a heads up that it's happening.

I'm a mechanical engineer originally. I've been doing brake work for almost 50 years on my vehicles. I worked for 10 years for a company that made OEM and aftermarket brake parts. IMO, there's some vulnerability in the Al-Ko system that--when triggered--causes bad things to happen. As I detailed before, I've tried nearly everything this time. It locked up on the way back from TSA/Dallas last summer so I did a lot of maintenance/adjustment/replacement then and thought I had it fixed. And apparently I did--for a while. But on the way back from Columbus, OH last month (after the Stds. were postponed), I had to brake hard. I pulled over a few miles later and, sure enough, same problem. I just disconnected the brake system then to get home (I've had a lot of practice). More work after that. Last week on the way to and from Blairstown, the same problem. I'm running out of things to do.

There's a problem. I'm sure something is out of adjustment or alignment or something somewhere. And when that happens, disaster. As much as I love [most] German engineering, I shouldn't have to ship the trailer back to Germany to get it to work right!

Chip Bearden

Chip,

don't get me wrong - that has nothing to do with waving the German engineering flag! I am a ME too and deal a lot with complex mechanical systems.
Your brake system is purely made up from levers, cams, pull-rods, bell-cranks and maybe a set of Bowden-Cables. Somewhere in that system is one element, which - when you brake hard - goes into a lock-up condition and won't release. It could be a cam that rotates too far or a pull rod, which gets hung up somehow. I found a few YouTube videos showing how to adjust an ALKO Auflaufbremse but they are all in German.
Have you contacted Spindelberger (or W&W) to get a schematic for your axle and brake set-up? I am sure they can provide you with a trouble shooting guide and an adjustment instruction. With some additional info, you can return the system to function properly - it's not rocket surgery!

Uli
'AS'

OK...general tire info from someone that does PT work in a tire shop.....

BTW....I did a real long reply to this thread.....whatever reason it evaporated.......

Tires....age is a killer.

On pretty much ANY tire is a mold date. Shop should NOT sell as new beyond 3 years from mold date.
Period.
At least in the US (likely other locations), should be a molded oval about 1"X1/2"...,,(metric.....figure it out....inches landed on the moon...nuff said.....yes, biased....).
There should be a 4 digit number......first 2 is week of the year .....0-52, last 2 is last 2 of year........
So.....a "4217" is......42'nd week of the year 2017.

"Thou shall not sell as new beyond 3 years from mold date".
Period. I believe US law.
Prime reason, from decades of dealing with tires,.....age....usually UV aging added to low pressure. Ramy does a lot of travel....so he is on the good side. He checks pressures, does miles, a perfect tire/I'm loses some pressure over time....not counting the "rule of thumb" that tire pressure changes about 1 PSI/*F change in temp. Metric guys.....figure it out...
Sitting on low/flat tires does NOT help.
Old tires lose their flexing, thus overheat and tread thrown.

Yes, US is usually longer trips at higher speeds.
No slight on other regions.

I see more blown tires from trailers sitting for years, likely low in pressure, then subjected to high highway speeds with aged tires.

Discuss......

I have a 1990 Cobra with non functioning brakes due to a blowout where I didn't catch it and drug the trailer quite a ways and tore up the drum assembly.
I've got to get a Dexter Axel on there with electric brakes. I think having functioning trailer brakes even at fairly low weights is very important.
A pickup pulled out in front of me this summer and I had a wild scary close call, having trailer brakes would have been very good. I was lucky I didn't T-Bone him and have a very nasty accident. Highway travel is dangerous.

"Highway travel is dangerous."


Nick- we didn't worry so much about dangerous situations when we were hang gliding with JZ and Zoardog. What changed? Lightning strike or something? ;-P~~~~

I pulled the drum off the wheel that was hot enough to steam water Both ends of the sealed bearing fell out along with most of the ball bearings! I believe the bearing was in the process of failing from overheated brakes after an hour of down hill towing......hwy80 west of Reno. W&W didn’t have the replacement and Cobra is on Holiday, but I was able to find it on line for $45/ea after giving ID 30mm, OD 60mm, H 37mm ( old bearing was. Armed AL-KO 581736).
This is the second time I have had very hot brakes after an extended downhill tow. I have fitted a simple brake lock-out that prevents the surge brake from surging! It consists of a piece of plastic pipe who’s ID matches the OD of the surge cylinder (2� pipe X3.75� for my Cobra), split it into two halves with a hacksaw and place them on the surge brake in the fully extended position. Secure them with two hose clamps and I’m good to go down the Sierras without hot brakes! E-mail me for photo.
JJ

PS, my blown tire was most probably age related, these new looking tires all have a born on date of 99!

I just changed the tongue damper on a 10/2007 Cobra.
Had been in procrastination mode. Perhaps others put that job off too?
Thanks for keeping the thread going as a reminder!
It took 90 minutes from chocking and jacking the trailer prior to removal until rolling it out with the new part installed.
This part I believe is critical in maintaining good braking behaviour.

There is an Al-Ko Workshop manual, covering axles, brakes, hitches and overrun devices. It also has lists of lubricants and accessories.

http://www.tabberiet.dk/T%40B-siden/...al%20AL-KO.pdf

The missing information for those with the square tongue:

Remove the jockey wheel.
After disconnecting the brake rod, remove the two bolts holding the drawbar onto the tongue.
Remove the drawbar.

Tools:
17mm open end for the brake rod. 19mm socket and open or box for the other bolts. Alignment tool for the new damper. Torque wrench.
Options:
Hammer, beer.
Jim

JS is spot on
I was taught if you can't fix it with a hammer its probably electrical.