A Spare Tire That Fits Under the Load Floor

[bandit81]

@vexingv I just checked my wheel (I did not drill it yet) and you are right, I got a brand new one from ecstuning.com and the holes are already larger than 9/16". I am going to try a 14mm bolt in it and see what kind of clearance it has. It may be that @kjechel 's situation - by first using the conical nuts it stretched the metal holes, then when using a flat washer it compressed the metal causing the holes to dig into the stud threads. It may be fine as-is. TO THE GARAGE!!!

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[bandit81]

Okay interesting. I will post a picture tonight but the inside of the holes the metal is super thin. I hit the back side of the holes with my step drill bit first, then from the front (outer wheel) side I smoothed any rough edges with a couple taps with the step bit, basically using it to debut the hole. It's not quite 5/8" this way, but it removes the thin edge of the metal in the holes from deforming into our wheel studs. I suspect if you use a conical once and press the metal inward, then a washer nut 2nd time you would then push this thinner metal inward then easily knock it off with the 9/16" step bit.

 

[vexingv]

I had to go back and reread this thread from the begining. I must have missed it before, but @Compromise had this same situation in post 64, but incrementally torqued in post 71.

Another user asked about drilling 5/8ths from the get go, but I'm not sure what the outcome or if that path was taken.

I guess being lazy is not going to work!

Thanks for checking @bandit81

 

[vexingv]

Thanks for a great write up and some great advice.

I understand your iterative, tighten, deform, check, re-drill process.

If I were being just a bit lazy, would you believe that it’s simplest to just open up the holes to 5/8” and be done?

Did you ever get around to this project? Did you initially drill using the 5/8th step from the start? If so, how did it work out for you?

 

[eric123406109]

Did you ever get around to this project? Did you initially drill using the 5/8th step from the start? If so, how did it work out for you?

Funny you ask. Just today, I received both the wheel and tire and have had them mounted. All of the materials have come in from Amazon.

Despite my initial desire to be lazy, I think I'm going to follow OP's recommended approach. It's clear he's a careful engineer and has thought this through. (I'm a slightly less careful engineer, and respect good practice when I see it).

The time effort/investment in the iterative process is not a lot, and may pay dividends by not removing more material than absolutely necessary.

 

[bandit81]

Oh in case anyone is wondering, the hole is 15mm which is slightly larger than 9/16" (14.30 mm). 5/8" is 15.88mm. The most ideal size to drill the hole out to is 5/8" if you do not compress/disform the holes. I did one hole to 5/8" and it still leaves plenty of mounting surface.

We most likely need a disclaimer, do this at your own risk, spare wheel speed maximum is 50 mph, make sure to use a torque wrench, doing this method is at the risk of the owner, etc..

For me this is the "emergency" emergency wheel. I am getting another set of wheels and tires for winter and will use one of those wheels in a pinch before I use this one. Not being stuck stranded somewhere is why we're going through this hassle in the first place.

 

[vexingv]

Oh in case anyone is wondering, the hole is 15mm which is slightly larger than 9/16" (14.30 mm). 5/8" is 15.88mm. The most ideal size to drill the hole out to is 5/8" if you do not compress/disform the holes. I did one hole to 5/8" and it still leaves plenty of mounting surface.

We most likely need a disclaimer, do this at your own risk, spare wheel speed maximum is 50 mph, make sure to use a torque wrench, doing this method is at the risk of the owner, etc..

For me this is the "emergency" emergency wheel. I am getting another set of wheels and tires for winter and will use one of those wheels in a pinch before I use this one. Not being stuck stranded somewhere is why we're going through this hassle in the first place.

It's still hot so I haven't gotten around to trying anything yet...

So you drilled one hole to 5/8 (virgin hole --not having been previously mounted/torqued it?)? Did it deform at all when you torqued it on the hub with the flat flange nut? Was it still easy to remove the wheel off the hub/studs?

Maybe an obvious answer, but when it is said to lubricate the stud, I assume the base of the stud or the hub surface itself and not the threads on the studs, right? (Torque would be totally inaccurate if the stud threads and nuts become lubricated).

Clearly this wheel is only for emergency, short purposes as most temporary spares are.

 

[kjechel]

Maybe an obvious answer, but when it is said to lubricate the stud, I assume the base of the stud or the hub surface itself and not the threads on the studs, right? (Torque would be totally inaccurate if the stud threads and nuts become lubricated).

Anti-seize is applied to threads, to prevent galling and also inhibits corrosion. It's good practice to apply it (sparingly) to wheel studs so the nuts will come off easily even after being left on for long periods of time. Reduce torque values by 20 to 30% compared to dry torque specs.

Here's a video on How & When To Use Anti-Seize

 

[vexingv]

Anti-seize is applied to threads, to prevent galling and also inhibits corrosion. It's good practice to apply it (sparingly) to wheel studs so the nuts will come off easily even after being left on for long periods of time. Reduce torque values by 20 to 30% compared to dry torque specs.

Here's a video on How & When To Use Anti-Seize

So just to clarify, those torque values you mentioned earlier at which you test fitted the nuts, those values are with anti-seized applied on the studs? Or should one further reduce the torque (or conversely, increase the torque if it is a dry application with no anti-seize)?

 

[bandit81]

I thought the anti seize was for the hub centric rings only.

I would NOT add anti-seize to wheel studs, doing so changed the torque. When a lube is used on bolts/studs, the better way to measure torque is with a stretch gauge. If you anti seize your studs plan on using brake clean to clean it off before putting regular wheels back on.

@kjechel did you say you have an engineering background?

My intent was to NOT get the wheel stuck to the studs by removing material before bolting the wheel to the car. If we follow this procedure of using a 14mm conical nut first on a wheel designed for a 12mm conical nut, we first will distort the hole at the top portion (changing the strong pressed round shape into a bend). I have no intention of repeating what was tried here using a 14mm conical nut on this wheel. When applying a flat washer, we will distort the hole again. By first not hitting the hole with a conical nut we hopefully minimized the redirection of the metal in the hole. The hole starts at 15mm and after the first 2 steps it becomes tight against a 14mm stud. As long as we remove some material where this happens we should be good. 5/8" may be too much but it does not appear to be from my drilling yesterday.

I can draw sketches of what happened to the metal, but using a conical bolt first would distort the hole to point the edge material inward. Either way, this wheel was designed for 12mm conical nuts, it was not designed for 14mm conical nuts or flat washers, using either or both will manipulate the holes. I am 100% confident there are wheel engineers who would read this and be very disappointed by our "hackary".

 

[thui001]

I got the Dorman 611246 lug nuts, they are perfect for this situation.

Each lug nut is 2 piece, the washer has ribbed spots along the face that goes against the wheel which will act as a "lock washer". The nut pivots against the washer.

Parts list

• Dorman 611246 lug nuts (from a 2006 F-250 Super Duty), quantity: 5
• Wheel BMW 36116758778 (17x4), has a center bore of 72.6mm.
• Spare Tire 115/95R17 (Continental sContact 115/95R17 recommended)
• Hub centering ring 64.1mm to 72.6mm (pick aluminum instead of plastic)

Tools

• Step drill bit - for widening holes on the wheel to 9/16

Instructions

1. Buy the parts listed above
2. Modify the wheel's the lug nut holes to 9/16" diameter (do this before mounting a tire to it, that way you do not have to get the wheel re-balanced)
3. Test mount wheel on your car to verify fit with hub centric rings and lug nuts
4. Take wheel and tire to get mounted and balanced (plan on buying a valve stem at the tire center you pick)
5. Final test mount wheel with tire mounted to car. No need to test drive but you could.

Note: When tightening lug nuts for steel wheels, torque to 84 ft lbs (mentioned in this thread) or 85 ft lbs for simplicity. Steel does not compress like aluminum which is why the torque amount is different. According to Tire Rack 14x1.5M should be between 85-90 ft lbs unless stated otherwise by factory. Factory Type-S wheels should be torqued to 94 ft lbs for reference. Torque wrenches can be off by +/- 3%, don't over think this like I am now writing this.

Note 2: Normal wheels do not need the hub centric rings, but it is still good practice to use them so you are 100% sure the wheel is centered on the hub/axle. In this situation you MUST USE A HUB CENTRIC RING as the lug nuts will not center the wheel.

for the lug nuts, i am able to find Doorman 611246.1; by any chance do you know if they are compatible. Thank you.

 

[bandit81]

for the lug nuts, i am able to find Doorman 611246.1; by any chance do you know if they are compatible. Thank you.

I am pretty sure it's the same part except the .1 may mean that you are getting a quantity of 1. I got mine from Rockauto, much cheaper than if you go to AutoZone. You want them to support M14 x 1.5 thread.

Also when searching, dorman part numbers are 6 digits with a dash between digit 3 and 4, 611-246. When searching I always try their format, as well as with a space in quotes "611 246" and one all together 611246 (Rockauto style). The worst part numbers are from folks like Power Stop, Raybestos, and Centric - really hard to search for them.

 

[bandit81]

The .1 means one pack, otherwise you have to buy a pack of 10 it appears. If you look at my photo it has the .1 at the end of the part number, it's hard to see sorry.

 

[thui001]

I am pretty sure it's the same part except the .1 may mean that you are getting a quantity of 1. I got mine from Rockauto, much cheaper than if you go to AutoZone. You want them to support M14 x 1.5 thread.

Also when searching, dorman part numbers are 6 digits with a dash between digit 3 and 4, 611-246. When searching I always try their format, as well as with a space in quotes "611 246" and one all together 611246 (Rockauto style). The worst part numbers are from folks like Power Stop, Raybestos, and Centric - really hard to search for them.

Thank you so very much ….

The .1 means one pack, otherwise you have to buy a pack of 10 it appears. If you look at my photo it has the .1 at the end of the part number, it's hard to see sorry.

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