Biggest deflated spare tire in stock location? (1 Viewer)

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I have an OEM spare with a worn 285/70R17 BFG KO2 on it and it fit, fully inflated, in the stock position with no issues. It doesn't quite go up to all the stops, but its close enough!

Do you have your hitch installed, and does it touch against the panhard bar?

Anyone have any luck with a used deflated 285/75 in the stock spare area?
I want that size, and I’m willing to remove the hitch temporarily, and carry an inflator to fit it. Until a rear swing arm can be procured.
 
I have an OEM spare with a worn 285/70R17 BFG KO2 on it and it fit, fully inflated, in the stock position with no issues. It doesn't quite go up to all the stops, but its close enough!
are you running a hitch? thats the issue Im having
 
So I've got 33x12.5x17 tires, and I'm wanting to get a spare that'll be suitable in the stock location. I'm considering buying a cheap (non-AT) 285/70/17, so it should have a lower profile to an AT, less sidewall knobs etc, and maybe be easier to fit in stock location. I also have Curt aftermarket hitch.

The 33x12.5 K02 I have has an overall diameter of 32.5"

Something like a Yokohama Geolander has a diameter of 32.8" - only like $180 from Tirerack.

I think the difference should be ok? And perhaps should fit
 
So I've got 33x12.5x17 tires, and I'm wanting to get a spare that'll be suitable in the stock location. I'm considering buying a cheap (non-AT) 285/70/17, so it should have a lower profile to an AT, less sidewall knobs etc, and maybe be easier to fit in stock location. I also have Curt aftermarket hitch.

The 33x12.5 K02 I have has an overall diameter of 32.5"

Something like a Yokohama Geolander has a diameter of 32.8" - only like $180 from Tirerack.

I think the difference should be ok? And perhaps should fit
Here's a 33x10.5 with most of the tread worn off. I believe these are 32.6" when new. They start out at 19mm of tread and this one has maybe ~6mm remaining. I have the full stock hitch and a 2" lift in the rear with the spare pushed as far back as possible. I don't think a fresh tire would fit for me.

20210327_142149_HDR.jpg


20210327_142201_HDR.jpg
 
Reviving this thread and adding some additional pictures as I recently spent some time trying to shoehorn my full size spare up underneath. I included lots of detail since the information I was able to find on this forum and facebook groups was mostly anecdotal.

Hardware Details
  • Vehicle: 2007 GX470 with full frame mounted hitch (mounted at the rear cross member and on each side frame rail)
  • Tire: BFG K02, 285/70/17 with ~15k miles (I do 5 wheel rotations every 3-5k miles)
    • Diameter at 30psi = 32.6875 (32 11/16)
    • Diameter at 10psi = 32.5625 (32 9/16)
  • Wheel: Method MR701 17x8.5 0mm offset
  • Suspension: Eibach protruck lift 2.0 (~2 inch), stock rear control arms
Installation Trials
  1. I first tried to install the spare at ~30 psi, and it interfered with both the panhard bar and the rear hitch. I likely could have wedge the tire up higher, but don't have a desire for the tire to be installed with a hard interference on the panhard bar.
  2. Next, I aired the tire down to ~10 psi and was able to lift the tire most of the way up into the spare tire well. There was minimal clearance in the FWD and AFT direction (1/8" or so). However, this was at static ride height so the clearance will be reduced under bump as the axle swings through the control arm arc. The tire didn't make full contact against the upper frame stops as designed due to the larger diameter which allows the tire to tilt side to side slightly. The tire appears to bottom out early on the FWD frame stop and doesn't contact the side stops. I doubt this would cause any problems on road or even slow speed offroad, but I'd prefer to secure the tire better for the washboard roads we see here in California.
Next steps for me
  • I plan to remove the frame mounted hitch which should buy more rear clearance before the tire hits the rear cross member and reduce the chance of contacting the panhard bar under bump. I'll likely get the "slim" hitch that only mounts to the rear cross member. From what I can tell in pictures this should still give more room than the full size hitch.
  • I will try airing down to 5psi to see how much more the diameter reduces. I keep an air compressor in the vehicle at all times and I'm fine with having to air back up if I ever get a flat.
  • I'm also thinking of getting some medium or high durometer rubber to install between the tire and frame stops on the left or right hand sides to take up the slop I saw. I'd like to have three points of contact for the tire and right now I'm only seeing two contact points.
30psi Installation Pictures
Rear hitch contact at 30psi
Rear_contact_30psi.jpg


Front pandhard contact at 30psi
Front_contact_30psi.jpg


10psi Installation Pictures
Installed view at 10psi
Installed_10psi.jpg


Rear fitment at 10psi
Rear_fit_10psi.jpg


Pandard fitment at 10psi
Front_fit_10psi.jpg
 
Adding a few more images that got cutoff the last post....

Forward most vertical tire seat. It looks like the OE tire would contact the flat section and be locked in with the tire geometry. The contact point with the 285/70/17 tire is on a convex surface so you don't get much side to side rotational control.
Front_Vertical_Seat_10psi_2.jpg


Left hand side contact point. I believe the tire should bottom out on this cross member, so I'm thinking of shimming the gap with some high durometer rubber.
LHS_Vertical_Seat_10psi.jpg
 
Maybe a dumb question or idea but no fold away hitch mounted tires carriers for .... just to use on expeditions or for offroad proposes only

People who don't push their vehicles limits off-road think that they look cool. They're actually pretty stupid if you care about departure angle, you lose a lot of clearance. When I see a lifted vehicle with a hitch mount tire carrier, the first thing I think is "Wow that person has no idea what they are doing."

Swing-out bumpers provide both a place for the tire and increased clearance, generally. In reality, any swing out is going to be super annoying on the GX if you like accessing the rear compartment frequently. I've had dual swing out bumpers.. would not buy one again especially at the outrageous prices they cost now.

I opted for the rear door tire carrier from Bison Gear and an R4T bumper. Great clearance with the bumper. Yes, my rear door is starting to come apart from the tire carrier after about a year. I drive it hard, and fast off-road. No, I don't care... I can buy half a dozen junkyard rear doors for the price of a dual swing out bumper and I don't have the annoyance of opening 2 swing outs before opening the rear door.
 
I took another pass at getting my 285/70/17 BFG K02 stuffed up underneath. I deflated the tire down to 5psi and removed the frame mounted hitch. I'm not sure that either of these really had a significant affect, but the tire does seem to sit a little tighter up against the frame interfaces.

I also took a closer look and determined there is one contact point in the front and two in the rear. Even with the oversized tire you make decent contact with each of these, so I'm going to run the tire underneath for a while around town and see if anything shakes loose.

I would say this is the max diameter you can get underneath without making hard interference with the track bar.

These are the three contact points.
Underneath WO Hitch.jpg


The 285 hangs about as low as the frame mounted hitch would sit. I'm deciding if I should put the frame hitch back on or get the rear cross member "slim" hitch since I don't intend on actually towing anything.
Rear view at 5psi_2.jpg
 
I took another pass at getting my 285/70/17 BFG K02 stuffed up underneath. I deflated the tire down to 5psi and removed the frame mounted hitch. I'm not sure that either of these really had a significant affect, but the tire does seem to sit a little tighter up against the frame interfaces.

I also took a closer look and determined there is one contact point in the front and two in the rear. Even with the oversized tire you make decent contact with each of these, so I'm going to run the tire underneath for a while around town and see if anything shakes loose.

I would say this is the max diameter you can get underneath without making hard interference with the track bar.

These are the three contact points.
View attachment 3824770

The 285 hangs about as low as the frame mounted hitch would sit. I'm deciding if I should put the frame hitch back on or get the rear cross member "slim" hitch since I don't intend on actually towing anything.
View attachment 3824780
I run a never-used spare BFG KM3 255/75R17 (32.1” tall by 10”
Wide) tire in the spare location and it fits fully inflated on a FJC steelie wheel.

My current 285/70R17 tires are about half worn and probably measure about 32.5” tall by 11.5” wide, so the difference in height to the fully threaded KM3 is insignificant and could be adjusted by how much you deflate the main tires

Anyways, just throwing it out there that you can run skinny tall tire in the factory spare location and it tucks in there pretty good.

Once I go to 285/75R17s (33.86” by 11.26”) tires (aka 34s) then I’ll be going to a frame mounted tire swingout carrier to carry a matching 34
 

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