Help design a better tire carrier hinge.

[AJsArmor]

We've been using the spindle/bearing setup for years, but with more people wanting to throw larger tires on the back...along with a gas can mount, hi-lift mount...

Not feeling real cozy about that setup, would much rather see something in double shear if possible. My first thought was to weld in solid chunk of cold rolled steel, 1.25-1.5", drill and tap the top for a support. Use a delrin sleeve with thrust bearings top and bottom for longevity.

Problem is there's just not a lot of space on top of a bumper for much. It'd be a lot easier to put the hinge on the face, but then it gets into a matter of looks and most people don't want it there.

Key points to a hinge design...

Needs to stupid strong.

Needs to be fairly simple to keep costs low.

 

[5-90]

Double shear? Lemme throw this at ya (no pix, but I hope you'll get the idea.)

Either short tabs on the bumper face, or an angled head on the "swing arm" to allow it to rest in between the bumper plates in a pocket (for a semi-flush appearance.) Drill for clearance for, say, a 5/8" or 3/4" bolt, and make sure you can access the nut and the bolt head.

You should be able to find a bearing that will handle passing the bolt through the centre - a slight loose fit to about a .0005" interference fit, I think - and a sleeve could be used for a spacer. Tapered rollers can be had fairly small, so you can eliminate the use of the thrust bearing by using opposed tapered rollers, and the endplay can be accounted for in install preload for the bolt and nut, once you have figured the elastic deformation of the tabs (which is why I mentioned that the bolt should be so large!)

The swing arm proper can have lightly machine pockets to accept the outer race of the bearing - a similar fit for the inner race to the pin (.001" loose to .0005" tight,) with a slot cut across the counterbore to accept slide hammer jaws to allow for bearing replacement on the light press-fit. The new bearing can be frozen and dropped into the hole at that fit (since the OD of the bearing for a .625-.750" pin will be around 1.500" or so, I think. I'd have to check.) The counterbore should not be the full depth of the bearing - or spacers should be used - to allow pressure from the tabs to take up preload. This would create difficulty with sealing lubrication into the bearing, unless sealed assemblies with tapered rollers could be had.

Either a COTS bolt and nut could be used for the centre pin, or a piece could be machined rather quickly from bar stock (and perhaps, for ease of assembly in the shop, have a nut put on one end and pinned in place.)

Just first thoughts...

 

[squirrel80]

Protofab uses heims on their tire carrier. The cool thing is they can adjust if it sags at all.

http://www.protofab4x4.com/products.php?ID=00&ID2=32

 

[Ironmen77]

This works well.

 

[OverlandZJ]

I'm going to have a new swingaway made up soon, i'v been looking at spindles and i found this one. I think it's the largest available that i'v been able to find, rated at 3500#.

My plan is for tire and hopefully 3 fuel/water cans.

http://www.4x4labs.com/fabricationproducts.shtml

 

[aparke4]

i have a design i built once and sold a long time ago and i have not really seen anything like it - i have a sketch up rendered file too lemme see if i can find it

it is by far one of the strongest XJ bumpers i have seen

 

[AJsArmor]

I'm going to have a new swingaway made up soon, i'v been looking at spindles and i found this one. I think it's the largest available that i'v been able to find, rated at 3500#.

My plan is for tire and hopefully 3 fuel/water cans.

http://www.4x4labs.com/fabricationproducts.shtml

See that uses a trailer spindle as well and eventhough it's rated at 3500# I've seen a pic of a failure on that size as well. The smaller ones rated at 1000lbs should technically be more than enough. However there's something about the way the load is on it that stresses it or just some aren't manufactured very well that causes them to fail.

Originally I thought it came from welding them in too hot but I've built new axles for trailers, buzzed those spindles in hot and quick...never a problem.

I like Protofab's setup, just would like something simpler. Like what 5-90 is saying, I think what we can do though instead of having the hinge pin go into the bumper, is have it just past the bumper face. I can't explain it, let me draw something up and throw it out there.

 

[OverlandZJ]

I'v seen pics of the spindle you frenched in the rear flat surface, and was seriously considering copying. Are you seeing stress fatigue with that?

For a double shear setup maybe using this setup tapped to accept a bolt on top?

http://www.4x4xplor.com/images/LoD-Xpedition/DSC00503.jpg

I like the way this was designed.

http://www.pirate4x4.com/forum/attachment.php?attachmentid=258347&stc=1&d=1155348445

That thread has been brought back as well. Looks like Zach is looking for an alternative to the 1K spindles.

 

[shelbyluvv]

What about using a spindle and hub from a Chevy car? You would have to machine the rotor off the hub but, that can't be to hard with a lathe.

They are designed to hold up to the abuse of having a heavy car put on them constantly.

I thought about doing it when I built my carrier a few years ago.

 

[AJsArmor]

I'v seen pics of the spindle you frenched in the rear flat surface, and was seriously considering copying. Are you seeing stress fatigue with that?

For a double shear setup maybe using this setup tapped to accept a bolt on top?

http://www.4x4xplor.com/images/LoD-Xpedition/DSC00503.jpg

I like the way this was designed.

http://www.pirate4x4.com/forum/attachment.php?attachmentid=258347&stc=1&d=1155348445

That thread has been brought back as well. Looks like Zach is looking for an alternative to the 1K spindles.

In all honesty we had one snap off. In 9 years and hundreds of bumpers, we've never had any problems. This bumper wasn't even a year old. I'll throw up some pics to show you but it looks like it was possibly a bad part. It may never happen again, I don't want to find out. I think it's fine for the basic tire carriers, since we've got some out there that have a lot of wear and tear on them without a problem.

What about using a spindle and hub from a Chevy car? You would have to machine the rotor off the hub but, that can't be to hard with a lathe.

They are designed to hold up to the abuse of having a heavy car put on them constantly.

I thought about doing it when I built my carrier a few years ago.

It's a good idea that has been done with other spindles. Really cool when using a 4wd spindle and hub you can lock the position open. But just not practical for production use.

 

[AJsArmor]

Here's the pic. The ones I've seen from homebuilt bumpers snapped off lower, right where you'd expect to have a HAZ at. This one snapped off quite a bit higher and you can see how it's not crystallized all the way across. It's even rusted in that area indicating that was like that for awhile. The clean break is an obvious stress break, that small portion couldn't handle the load.

We're very careful about the installation of these, pre and post heating, reinforcement of the entire area. We don't just put them in and burn them.

 

[srimes]

what size spindle was that?

 

[garr]

How about not relying on the Hinge as the sole support & add some kind of extra support that connects to the rear hatch, Sort of like the type used on the old Ford Bronco OEM tire carrier.
A steel plate that mounts to the rear hatch that the carrier slides in & latches.
This should take some of the loading off of the hinge making for a much sturdier design.
It is always better to not put all your eggs in the same basket!!

 

[srimes]

How about not relying on the Hinge as the sole support & add some kind of extra support that connects to the rear hatch, Sort of like the type used on the old Ford Bronco OEM tire carrier.
A steel plate that mounts to the rear hatch that the carrier slides in & latches.
This should take some of the loading off of the hinge making for a much sturdier design.
It is always better to not put all your eggs in the same basket!!

I don't know about the hatch, but building off this idea maybe going off rear quarter panel armor? Not everyone runs armor there, but if you have the plate there already one could hinge off of that with plenty of spacing.

 

[slcpunk74]

If I were super worried about using a spindle I would use a 3500# spindle wedled at the bottom like above but also have a top part that would bolt to the face of the bumper and be tied into the spindle via the spindle nut. I think a 3500# spindle in double shear would break a weld long before it would snap.

I am a trailer mech and I dont see many spindle failures especially on 3500#. I think the trailer spindle is a good idea, but there has to be a better(cheaper) way.

 

[AJsArmor]

After some trial and error, here's what we came up with. Still uses tapered roller bearings but no stinkin' spindles. The difference in strength is literally night and day, I wish I would have used this setup years ago and never looked back. Tweaking a little bit on the design yet and will incorporate a lock open feature as well. Still sourcing some better looking hardware. ALSO...will be available as a DIY kit. :eyes:

 

[OverlandZJ]

Looks good. PM coming..

 

[asp]

ALSO...will be available as a DIY kit.

you have my attention....

 

[jeep pox]

ya so when does this kit come?

 

[wheelinscott]

ya im way interested in the diy myself, let us know when its available.

thx