What is the best point to jack up a Cobra Trailer ?

[[email protected]]

I changed a wheel in my Cobra trailer with the glider inside. I located the Jack just under the corner between the bottom and side wall, next to the fender.
Looked flimsy, but held fine, no bending of wall or edge.
Was I lucky or is this the right place to do it ?
Dan

[[email protected]]

Terrible point to jack from. Puts stress on the floor, sidewall and suspension. Jack should always be placed under the axle itself. Plus you don't have to lift more than a few inches to get the tire off the ground. Jacking up the "box" requires you to lift it high enough for the suspension to extend fully. Don't do it again!

[Bob Kuykendall]

On Wednesday, November 7, 2018 at 9:13:20 AM UTC-8, wrote:
> ...Jack should always be placed under the axle itself...

The typical Cobra has a trailing-arm suspension that doesn't really have an "axle" to put a jack under, not like a car at least. The next best thing is the steel crossmember that contains the torsion springs. But even then, you have to raise it enough to extend the suspension.

--Bob K.

[Steve Leonard[_2_]]

On Wednesday, November 7, 2018 at 10:36:19 AM UTC-6, wrote:
> I changed a wheel in my Cobra trailer with the glider inside. I located the Jack just under the corner between the bottom and side wall, next to the fender.
> Looked flimsy, but held fine, no bending of wall or edge.
> Was I lucky or is this the right place to do it ?
> Dan

You did fine. On the cross member, as Bob K suggests, can end up as an awkward lift if the tongue weight is low. That point could actually be ahead of the CG, so being tied down at the front becomes important. If the side extrusion wasn't stressed for handling the axle loads, the axle wouldn't be secured to it. And you know where the axle is attached. Just don't slip over onto the floor board section, as that is pretty thin aluminum on foam, and it will compress and fail if you put a jack on it to pick up one side of the trailer. Best stick close to the outside edge of that "corner", as the tabs that the floor sticks into are about an inch and a half or so long.. And you don't want to lift by them. You want to push straight up into the sidewall. Just like the axle attach does.

Steve Leonard

[[email protected]]

After reading Steve's response, I have to say that he is right and I was wrong. However, I do suggest that the jack should be placed under one of the crossmembers behind the fender, as Cobra often has the axle positioned slightly forward of the actual mid-point of the trailer box. On my (old) Cobra, the position is quite a bit forward of the middle. If there are no crossmembers on the newer Cobra models, I would suggest using a 12 inch 2x4 between the jack and the trailer body to spread the load somewhat. And don't forget to loosen the lug nuts before jacking the wheel off the ground.

[[email protected]]

Good stuff.

Off topic slightly, my old Komet trailer--steel tubing with aluminum skin and wood floor--had a doubler tube welded in alongside the lower longeron where the axle attached on each side. That weld between the doubler and the longeron eventually failed, allowing the axle mount on that side to push up, bulging the wood floor enough that the wing dolly wheel wobbled each time we brought out the wing. We initially thought it was just the wood floor warping after some years but discovered by crawling under the trailer and inspecting that the damage was more severe. Straightforward to fix: remove glider plus portions of the sidewall skin and floor, then drive it over to a welding shop to add reinforcement.

My Cobra has extruded side panels and an aluminum/foam floor. IIRC, the axle attaches via a short section of angle that acts as a doubler. Depending on the clearance, I've used a jack under that doubler and also under the pivot of the axle swing arm itself. I, too, use a short length of 2x4 to spread out the load if I'm jacking directly under the side panel where there's no crossmember.

It's important to note that if the trailer tongue is not fixed to the ball of the tow vehicle, jacking up one wheel can make the whole trailer somewhat unstable, even more so if the front dolly wheel--which is supporting the tongue--is partially extended and can swivel/roll. That's especially true if you're working on the brakes and therefore don't have the parking/emergency brake engaged. This is all hypothetical, of course; I've never had any close encounters with disaster. :)

Chip Bearden

[[email protected]]

Am Mittwoch, 7. November 2018 17:36:19 UTC+1 schrieb :
> I changed a wheel in my Cobra trailer with the glider inside. I located the Jack just under the corner between the bottom and side wall, next to the fender.
> Looked flimsy, but held fine, no bending of wall or edge.
> Was I lucky or is this the right place to do it ?
> Dan

You should try this:

https://www.cobratrailer.com/catalog/product_info.php?cPath=21&products_id=46&language=en&osCsid=kvav50lmt3kd97er1u9l1gedv2

That´s the perfect solution.

Regards
Bernd

[Nick Kennedy[_3_]]

I think you should do a practice run on your trailer, changing the wheel, at home before heading out on the open road. On the side of the interstate, with traffic whizzing by a 80 mph is no place to find out your jack doesn't work and your lug wrench is the wrong size.
Or your spare doesn't fit anymore due to a axle change.

[[email protected]]

On Friday, November 9, 2018 at 1:48:12 PM UTC-5, Nick Kennedy wrote:
> I think you should do a practice run on your trailer, changing the wheel, at home before heading out on the open road. On the side of the interstate, with traffic whizzing by a 80 mph is no place to find out your jack doesn't work and your lug wrench is the wrong size.
> Or your spare doesn't fit anymore due to a axle change.

Good advice. And remember that a jack that slips neatly under the trailer when the wheel is on the hub may not fit at all if the tire is flat or essentially missing (experience with both).

Chip Bearden

[Tim Taylor]

I added stabilization jacks on my trailer about at 3/4 of the length. The advantage is that they can be used to lift a wheel off the ground to change the tire. No need for a different jack.

[Nick Kennedy[_3_]]

Good one there Chip
Should make sure the jack is going to fit under there with a flat/ no tire left
One of my friends was killed on the interstate changing a flat back in the early 80's
Dangerous place to be.

[2G]

On Friday, November 9, 2018 at 12:51:57 PM UTC-8, Nick Kennedy wrote:
> Good one there Chip
> Should make sure the jack is going to fit under there with a flat/ no tire left
> One of my friends was killed on the interstate changing a flat back in the early 80's
> Dangerous place to be.

Was he killed by another car or truck, or was he pinned under the vehicle?

Changing driver's side flats is very risky business - been there, done that.. Pull over as much as you can off the road, or consider driving to a safe spot with the flat. If not possible, unhitch and position the tow vehicle into a position behind the trailer to protect you, like what police do when they stop a car (they are wider than the glider trailer). Obviously, turn emergency flashers on.

Tom

[Matt Herron Jr.]

On Friday, November 9, 2018 at 12:51:57 PM UTC-8, Nick Kennedy wrote:
> Good one there Chip
> Should make sure the jack is going to fit under there with a flat/ no tire left
> One of my friends was killed on the interstate changing a flat back in the early 80's
> Dangerous place to be.

I had a close call. The story goes like this;

On the way to a safari I spotted some fellow glider pilots on the side of the highway. They had a flat trailer tire on the right hand side, and were pulled off to the shoulder. I helped position the jack under the axle while another guy jacked it up to make contact. As this was my first time changing a trailer tire, I didn't think to check the hitch situation. They had already taken the trailer off the hitch and it was sitting on the front caster wheel.

I was on my back, just in front of the right trailer wheel, and as the jack started to take the weight of the trailer, the slope of the shoulder and the CG of the trailer started to rotate the trailer clockwise about 20 degrees as the trailer fell off the now tilted jack. The back end of the trailer rotated into the freeway...

Thankfully there were no cars in that lane at that moment. You can imagine what might have happened if there were. Next time the hitch stays on the ball.

[Charlie M. (UH & 002 owner/pilot)]

Always look for 3 points of contact, lessens issues.
Granted, I have been bit by that, currently working on a trailer that is iffy since one contact is a swiveling tongue wheel.

When in doubt, find SOMETHING to spread the load.
Be really careful on many newer Corvettes. Get it wrong, big bucks to fix correctly.
No, I didn't get hit, but I knew going in.

[Nick Kennedy[_3_]]

2G
That friend that was killed was hit by a car driven by 3 teenage girls. He had a left side flat and was working on it when they hit him about 6 feet to the right of the white line.

[[email protected]]

> They had already taken the trailer off the hitch and it was sitting on the front caster wheel.

NEVER jack up a trailer if the front dolly wheel can roll/caster. If you're going to jack up the trailer while it's off the vehicle's tow hitch, at least straighten the dolly wheel (parallel with the main tires) and then lower it all the way until it locks out the castering feature (most Al-Ko gear I've seen allows this). Then chock/block the main wheel that will remain on the ground. If you plan to jack up both wheels at the same time, however, put the trailer on the vehicle's tow hitch first.

Chip Bearden

[danlj]

On Sunday, November 11, 2018 at 10:03:10 PM UTC-6, Nick Kennedy wrote:
> 2G
> That friend that was killed was hit by a car driven by 3 teenage girls. He had a left side flat and was working on it when they hit him about 6 feet to the right of the white line.

Whilst traveling last spring to the Region 7 contest, I had a flat. A highway patrol soon parked on the shoulder behind me. She said nothing, did nothing -- but her flashing lights inspired drivers to use the left lane. Best. Thing.
DJ

[[email protected]]

There is a bracket for AL-KO trailers that Cobra uses. This is for a caravan. Should work.https://www.youtube.com/watch?v=bux1kg7wxCg

[AS]

On Wednesday, November 14, 2018 at 2:13:07 PM UTC-5, wrote:
> There is a bracket for AL-KO trailers that Cobra uses. This is for a caravan. Should work.https://www.youtube.com/watch?v=bux1kg7wxCg

Interesting! Looks sturdy but I guess one would need a special jack which 'slots' into the bottom of that bracket. I wonder if a standard jack could be used on the upper horizontal part of the bracket.
I will check the frame on my Cobra trailer this weekend.
Uli
'AS'

[2G]

On Sunday, November 11, 2018 at 8:03:10 PM UTC-8, Nick Kennedy wrote:
> 2G
> That friend that was killed was hit by a car driven by 3 teenage girls. He had a left side flat and was working on it when they hit him about 6 feet to the right of the white line.

A sobering exercise is to google "man killed changing tire" - it happens all too often.

Tom

[[email protected]]

I, too, had a flat on the trailer driver side. I 70, just starting rain, on a curve and just over a hill top. I called and waited for the Illinois State police to show up. It took a while and dusk was settling in. Nothing like having those flashing lights to slow things down. No way I was going to try it without him there. It was a quick change and he didn't even want my name when it was all over.

[AS]

On Wednesday, November 14, 2018 at 9:14:26 PM UTC-5, AS wrote:
> On Wednesday, November 14, 2018 at 2:13:07 PM UTC-5, wrote:
> > There is a bracket for AL-KO trailers that Cobra uses. This is for a caravan. Should work.https://www.youtube.com/watch?v=bux1kg7wxCg
>
> Interesting! Looks sturdy but I guess one would need a special jack which 'slots' into the bottom of that bracket. I wonder if a standard jack could be used on the upper horizontal part of the bracket.
> I will check the frame on my Cobra trailer this weekend.
> Uli
> 'AS'

Ok - went out to the airport today after almost week of solid rain in the Carolinas to check on the trailer and the frame underneath. There is nothing like the frame shown in the video under my trailer. Maybe it is because I have a double-axle trailer? Anyhow, I guess I will have to place the jack right under the axle tube should I have a flat. However, since I have a TPM-system, that chance is greatly reduced to a sudden, total blow-out. :-)
Uli
'AS'

[RR]

If you have a double axle traler, you dont need to mess with Jacks at all. I have a double axle airstream, and some "leveling blocks". I just make a ramp with the blocks and drive or back the trailer up the ramp on the good wheel an you are good to go. I still carry a jack just in case, but have never needed it.

[Tango Whisky]

Le lundi 19 novembre 2018 13:23:20 UTC+1, RR a écritÂ*:
> If you have a double axle traler, you dont need to mess with Jacks at all.. I have a double axle airstream, and some "leveling blocks". I just make a ramp with the blocks and drive or back the trailer up the ramp on the good wheel an you are good to go. I still carry a jack just in case, but have never needed it.

I too have a twin axle trailer. Changing the front wheels is plain simple - just raise the hitch with the front dolly wheel...
Doesn't work with the rear wheels, though. But then, no need for road side work as the trailer will run well on the 3 remaining wheels to the next shop. Last year I towed mine on 3 wheels on the highway for about 30 km, and the deflated tire didn't heat up at all.

[Jonathan St. Cloud]

On Monday, November 19, 2018 at 6:39:51 AM UTC-8, Tango Whisky wrote:
> Le lundi 19 novembre 2018 13:23:20 UTC+1, RR a écritÂ*:
> > If you have a double axle traler, you dont need to mess with Jacks at all. I have a double axle airstream, and some "leveling blocks". I just make a ramp with the blocks and drive or back the trailer up the ramp on the good wheel an you are good to go. I still carry a jack just in case, but have never needed it.
>
> I too have a twin axle trailer. Changing the front wheels is plain simple - just raise the hitch with the front dolly wheel...
> Doesn't work with the rear wheels, though. But then, no need for road side work as the trailer will run well on the 3 remaining wheels to the next shop. Last year I towed mine on 3 wheels on the highway for about 30 km, and the deflated tire didn't heat up at all.

Can you believe people ask me why I have a double axle trailer for an 18 meter bird.

[2G]

On Monday, November 19, 2018 at 6:39:51 AM UTC-8, Tango Whisky wrote:
> Le lundi 19 novembre 2018 13:23:20 UTC+1, RR a écritÂ*:
> > If you have a double axle traler, you dont need to mess with Jacks at all. I have a double axle airstream, and some "leveling blocks". I just make a ramp with the blocks and drive or back the trailer up the ramp on the good wheel an you are good to go. I still carry a jack just in case, but have never needed it.
>
> I too have a twin axle trailer. Changing the front wheels is plain simple - just raise the hitch with the front dolly wheel...
> Doesn't work with the rear wheels, though. But then, no need for road side work as the trailer will run well on the 3 remaining wheels to the next shop. Last year I towed mine on 3 wheels on the highway for about 30 km, and the deflated tire didn't heat up at all.

You really only need a 4x4 block to drive the good tire on - that lifts the flat tire so it can be changed. Works for either tire.

Tom