Spare tire swingaway for Greg Davis bumper?

[Blue]

Originally Posted by Jeff Blake

Thanks robert! Looks great, thanks for taking the time to mock that up. It's on the wrong side though,

I haven't seen a spindle with bushings as opposed to bearings. I'll keep looking around. The one I linked above has 2.25" OD on the sleeve, and I'm pretty sure it can fit with a minor cutout in the body panel.

But do you really want to hack up your truck? Or hack it up more?

[robertf]

The IPOR spindle is 2” od and uses bushings

[Jeff Blake]

Originally Posted by Blue

But do you really want to hack up your truck? Or hack it up more?

I don't mind. I need to do something about those missing plastic corner pieces anyway (other than getting plastic corner pieces). I've already done plenty of cutting... mantec snorkel, quarter panels, air fitting cutouts, roof holes, firewall is swiss cheese with all the wires...

I don't think 2" vs 2.25" OD is going to make the different either. I'll need ~9-10" of clearance above the hole for the spindle in order to fit the carrier.

Originally Posted by robertf

The IPOR spindle is 2? od and uses bushings

I talked with the guys at A-Z Fab today, and they were pretty adamant about bearings. They used to do bushings, but the failure rate was really high.

A-Z isn't concerned with the tire load being on the opposite side. He says weight is not the issue, it's stabilizing the carrier from any movement. He recommends a heavy duty plastic pad to go on the latch side, where the arm will rest on when closed. He also said it's important to have something to prevent forward to back movement, (i.e. stopping the car fast)

For those reasons, I liked the concept of 4xinnovations hinge http://www.4xinnovations.com/Swing-O...bly_p_109.html
As it has lock-pins for closed, 90 degree, and 130 degree open. But I don't like how it mounts to the face of the bumper, so it's out.

A-Z suggested 2x2x 1/8" wall steel for the carrier.

[fishEH]

I haven't had any issues with mine.

[robertf]

Originally Posted by Jeff Blake

I talked with the guys at A-Z Fab today, and they were pretty adamant about bearings. They used to do bushings, but the failure rate was really high.

A-Z isn't concerned with the tire load being on the opposite side. He says weight is not the issue, it's stabilizing the carrier from any movement. He recommends a heavy duty plastic pad to go on the latch side, where the arm will rest on when closed. He also said it's important to have something to prevent forward to back movement, (i.e. stopping the car fast)

For those reasons, I liked the concept of 4xinnovations hinge http://www.4xinnovations.com/Swing-O...bly_p_109.html
As it has lock-pins for closed, 90 degree, and 130 degree open. But I don't like how it mounts to the face of the bumper, so it's out.

A-Z suggested 2x2x 1/8" wall steel for the carrier.

I'm pretty adamant about not using bearings. Did they say what material or size bushings were failing? I don't believe a bronze bushing in the 1.25 and up shaft diameter is failing when holding up a 200lb tire 4' away

2x2 x 1/8" is probably fine. I went with 3 x 1.5, its slightly heavier but the deflection when open is around half. The extra half inch width adds no strength, only the vertical dimension is significant in this application.

They are right about stabilizing it. Thats one of the reasons I use the roller. When closed it deflects the beam upwards to pre load it, and the heim linkage is adjusted to compress the rubber bumper on the back to pre load it that way.

edit: Looked at their website. I see they have the spindle in double shear, thats how they are getting away with a spindle diameter small enough to trash bushings and not bend. theres no room for that on the top of the bumper

[Jeff Blake]

I think they were using bronze.. or was it brass? One of the B's.

My tire weighs in at 80lbs... what are you running, a tractor??

Anyway I haven't made much progress on this lately due to work.

I am still leaning towards the A-Z spindle, as its widely used, and I don't think 2.25" diameter will be an issue.

Next step is to order the hardware and drop by the welder to have a chat. Chuck ( https://www.yelp.com/biz_photos/d-an...C7fsZNKg6y0Slw ) has a cool outdoor shop by the beach and did the welding for the GD bumper. I want to have the parts in hand so he can better figure out what he wants to do.

I tried to source some 14x1.5 studs for the mount off Mcmaster, but no luck. But then I remembered I have two new wheel hubs sitting around, so I think I'll install one of those and use the old wheel hub for the mount... one less task for the welder.

For the clamp, I think I'll use a toggle clamp like fishEH.

Delrin pad for the carrier to rest on in the locked position

[fishEH]

Have your fabricator weld the tire mount at the same angle as the rear door. Not only will it look tight but it will move some of the tire weight back over the center of the carrier.

[Blue]

Do you think it makes a significant difference to mount the spare backwards (with the inside of the rim facing out) like Mercedes does on the G-wagon? It certainly makes sense because the weight of the rim's face is held further inboard. What's a Rover alloy rim weigh? About 30 or 40 lbs?

[fishEH]

Originally Posted by Blue

Do you think it makes a significant difference to mount the spare backwards (with the inside of the rim facing out) like Mercedes does on the G-wagon? It certainly makes sense because the weight of the rim's face is held further inboard. What's a Rover alloy rim weigh? About 30 or 40 lbs?

That doesn't make any sense.

[Jeff Blake]

Originally Posted by fishEH

Have your fabricator weld the tire mount at the same angle as the rear door. Not only will it look tight but it will move some of the tire weight back over the center of the carrier.

Good idea, thanks

Alright did a better mockup. This tube is 8" long, 2.25" diameter. The actual outer hinge tube is 4" long, but I figured I'll need twice the vertical clearance to install it.

It's awfully tight... it *might* work if the 1.5" diameter spindle is welded to the inside face of the bumper, so that the outer tube is offset towards the face, as in the picture.

Or... do a little body trimming...

Or...?

[Jeff Blake]

A-Z is recommending "You may need to slice the front face of the bumper and have the spindle half in and half out. We have done that before with good results."

Seems like a smart move.

[Blue]

Originally Posted by fishEH

That doesn't make any sense.

It does if the mounting plate is pulled closer inboard.

[fishEH]

Originally Posted by Blue

It does if the mounting plate is pulled closer inboard.

That seems like a major PITA, especially with an alloy wheel and the lug nuts.

[Blue]

Seems pretty cool, would love to have my spare mounted face-in almost directly on the door rather than cantilevered out on the mount.

On the other hand, people buy reverse mounts so they can have the matching dub facing outwards. LOL

http://911motorsports.net/Mercedes-G...W463_p_39.html

[robertf]

Originally Posted by Jeff Blake

A-Z is recommending "You may need to slice the front face of the bumper and have the spindle half in and half out. We have done that before with good results."

Seems like a smart move.

Sounds like what I suggested 3 weeks ago

[robertf]

Originally Posted by Blue

Seems pretty cool, would love to have my spare mounted face-in almost directly on the door rather than cantilevered out on the mount.

On the other hand, people buy reverse mounts so they can have the matching dub facing outwards. LOL

http://911motorsports.net/Mercedes-G...W463_p_39.html

Im running offset aftermarket wheels so there is no benefit to flipping the wheel. Id imagine most people running a wheel tire combo heavy enough to damage the door hinges are also running offset wheels

[fishEH]

Looks like the rubber is about as far off the door as with the stock carrier.

Originally Posted by Blue

Seems pretty cool, would love to have my spare mounted face-in almost directly on the door rather than cantilevered out on the mount.

On the other hand, people buy reverse mounts so they can have the matching dub facing outwards. LOL

http://911motorsports.net/Mercedes-G...W463_p_39.html

[Blue]

The point is that the heavier face of the rim is closer in if it's mounted (what we would call) backwards. It wouldn't make a difference if the face of the rim was exactly in the center of the rim in cross section but it is not.

[robertf]

Originally Posted by Blue

The point is that the heavier face of the rim is closer in if it's mounted (what we would call) backwards. It wouldn't make a difference if the face of the rim was exactly in the center of the rim in cross section but it is not.

The difference is about the same as having 1 additional beer in the cooler directly above the rear axle

[fishEH]

Originally Posted by robertf

The difference is about the same as having 1 additional beer in the cooler directly above the rear axle

Exactly. Its an over complicated solution to a non-existent problem.

[Jeff Blake]

Small update here

Parts are all ordered. Going for a pretty simple and traditional setup:

Spindle from AZ fabrication
Spring pin (for locking the carrier open - welded to spindle sleeve) https://www.mcmaster.com/#91712a119/=1c24bxt
Toggle clamp (had to get the 1000lbs version, as the u-bolt on the 2000lb version are too long) https://www.mcmaster.com/#5135a42/=1c24cah
Steel disc (will weld to the bumper, and the spring pin will lock into this) - https://www.mcmaster.com/#7786t62/=1c24cmb
Old wheel hub to use for the wheel mount (installed a new wheel hub today).. need to press the bearing assembly off, leaving just the plate

The best, and simplest latch design for the GD bumper I think is going to be a "corner bracket / hollow gusset", which serves multiple purposes: elevated area for the carrier to rest on, taking weight off the spindle, rear bumper to stop forward movement, and a right angle toggle clamp mounted on the carrier, with the hook on the outside of the corner bracket.

Here's a terrible drawing. The reason for the rectangular mount is so a table will fit on the backside nicely. Considering the wheel hub will be 4-6" away from this, do you think there will be any supports needed?
Once the spindle arrives I'll take the hardware to a local welder

[JohnHZ3]

I have been planning on doing this for a few years and finally got around to it thanks in part to this thread. The rear door was already damaged prior to my ownership and was difficult to close. The tire is 315/75R16 which is obviously way too heavy to be mounted to the door. I looked into all the parts offered for sale but decided none were exactly what I wanted. I liked the bushings of the Iron Pig spindle and the dual shear bracket of the Comp 4x4 version. I also liked the idea of a sleeve welded into the bumper rather than welding the spindle in place. This will allow for easy replacement or removal of the spindle in the unlikely event in gets damaged.

After measuring numerous times I drilled through the top and bottom of the bumper using a 2" hole saw. Then using an angle grinder with a cutoff wheel I connected the two circular cuts. A piece of 2" OD 1-1/2" ID tubing was tack welded as squarely as possible into the cutout. The hinge pin is 1-1/2" diameter steel. The carrier pivot is 2-1/4" OD 1-3/4" ID tubing with bronze bushings inserted (which were removed and replaced with new ones after welding). The frame is constructed of 3" x 1-1/2" (1/8 wall) tubing and 1-1/2" x 1-1/2" (1/8 wall) tubing. I added a dual-shear bracket to the pivot point to increase the rigidity. I modified and reused the mounting bracket which had been installed on the door for the rim mounting. After welding and mounting the carrier frame, I was disappointed by the amount of flex/bounce with the tire installed. All the flex was in the bumper itself and not the carrier or hinge. I ended up making an additional bracket, which mounts in the stock location on the door, to anchor the carrier to the door. It also doubles as the antennae mount. All the weight is still on the bumper. Everywhere a structural bolt mounts to the bumper I installed a rivet nut insert for added strength and grade 8 hardware was used. I am pleased with the appearance and strength. Having to loosen 3 screw-in handles is a bit cumbersome to open the carrier but ultimately I decided it was more important to have it securely attached.

[JohnHZ3]

More pictures

[jymmiejamz]

Nice work. It would be really cool if it were attached to the rear door like on a NAS D90 soft top tire carrier.

[K-rover]

That looks really good!