4x140 to 6x5.5" conversion questions

[froej25]

I tried to search for this info, to no avail. Maybe the article I read about the conversion (http://www.vintagesubaruparts.com/6lug.htm ) is erroneous somehow, if it hasn't been attempted here. Input is appreciated on this; brakes and wheels are kinda an important part of a vehicle (my dry humor), and I want to be sure this is done properly and safely.

So, my brother's BRAT needs new wheels / tires. We snagged the suspension off of the XT when we pulled the turbo motor, so we have everything we need for disc brakes. Rather than try to scrounge up something off of a Peugeot (Phew-got? Phew-go? Whatev'), or find the parts I need from an XT6 (already got the other ones), I'd rather go with the 4x140 mm to 6x5.5 inch conversion. I understand its possible- drill four new holes in the hub, leave two in place, add new studs- which is simple enough. It looks like from the pictures in the FSM that Subaru was even nice enough to attach the brake rotor separately, not utilizing the same holes that the studs go through to retain the rotor (saving me the headache of trying to figure out where to scrounge up rotors with the proper thickness, offset, and diameter to work with 6 lug wheels).

 

Now, the question is, where to find the right wheels? Unfortunately, the main candidates I would look for- S-10 / Sonoma and full-size GM cars- utilize a 5-lug wheel. So, looking at the options, is there any thought on which of these would be best; utilizing the following criteria:

 

6x5.5" bolt pattern

14 or 15 inch diameter

5-7 inch width

Correct offset (this will be the tricky one I think)

 

Model Year Diameter

Isuzu Amigo 89-00 15 x 6

Isuzu Pickup 80-96 14 x 6

Isuzu Rodeo 91+ 15 x 7

Isuzu Trooper 92-96 16 x 7

Isuzu Trooper II 84-91 15 x 6

GM big SUV 4wd 71-91 15 x 7

GM big SUV 4wd 92+ 15 x 7

GM big SUV 2wd 00+ 15 x 6(7)

GM ½ ton 4wd 67-87 15 x 7

GM ½ ton 4wd 88-98 16 x 7

GM ½ ton 2/4wd 99+ 16 x 7

GM ¾ ton 2/4wd 67+? 16 x 7

Dodge D-50 & Ram 50 2wd 79-93 14 x 6

Dodge D-50 & Ram 50 2wd diesel 83-93 15 x 6

Dodge Raider 4wd 86-89 15 x 6

Ford Courier 77-84 14 x 6

Jeep Full-size 74-92 15 x 6

Mazda B-series 77-93 14 x 6

Mazda B-series 77-93 15 x 6

Mitsu. Montero 83+ 15 x 6

Mitsu. Pickup 83-96 14 x 6

Mitsu. Pickup 83-94 15 x 6

Nissan Frontier 98+ 15 x 6

Nissan Pathfinder 87-96 15 x 6

Nissan Pickup 73-86 14 x 6

Nissan Pickup 87-96 15 x 6

Toyota Pickup 4wd 80-95 15 x 7

Toyota 4Runner 80-95 15 x 7

Toyota Pickup 4wd 86-95 15 x 6

Toyota Landcruiser 69-92 15 x 6

Toyota Tacoma 4wd 95-97 15 x 7

 

I'm inclined to think the LUV / Isuzu Pickup, Dodge D-50 / Ram-50 / Mitsubishi pickup, or Nissan pickup would be best, with their 14 x 6 size (compared to stock BRAT 13 x 5). I think 15s are too big for the BRAT; its not going to be lifted, and the tires would be too low profile with 15s or larger. The LUV will be rare to find, and the wheels are ugly, so the Mitsubishi / Nissan / D-50 will probably be the way to go; a lot more selection, and more recent vehicles. Hopefully the offset is close.

 

Stock tire size is 195/75-14 (for the Mitsubishi), Tirerack recommends 205/75-14 as an up-size. Stock BRAT tires are 185/70-13; roughly 23.2" diameter. A 195/60-14 is a hair over 23.2", but sounds awfully low-profile; a 195/65-14 ends up being a bit under 24", which shouldn't throw off the speedometer too much (maybe going ~65 mph @ indicated 60 mph), and shouldn't have any clearance issues (I don't think anyway). One of the biggest benefits of going to the 14s is tire selection; there are 6 options in the 185/70-13 size on tirerack, opposed to 22 options in the 195/60-14 size and 13 options in the 195/65-14 size.

 

So, any thoughts from people who've been there? Or anyone else that wants to throw in their 2 cents? And in a final safety note- is anyone aware of hub failure because of the extra material being removed? It would seem the wheel itself would help reinforce the structure by clamping it together, but if necessary we could probably fabricate a sort of backing plate and utilize extra long studs, effectively sandwiching the hub between the wheel and the backing plate. Not sure about balance, but I suspect it will be ok.

[86BRATMAN]

Theres really no science to it, at least mot in the easy manner. Knock out two opposing studs. Bolt up a six lug wheel onto the two remaining studs, and center mark the other four. Use a drill press and drill the four new holes. Grind some of the metal on back to let the new studs sink in just a bit. Install the new studs(weld them on for added safety if you like), bolt the hubs back on and install wheels.

 

Here's a write-up by one board member, Phizinza.

http://www.offroadingsubarus.com/6stud_conversion.html

 

Here's another helpful bit, a real size diagram of the different lug patterns in use on our cars, including the 6x5.5"

http://www.ultimatesubaru.org/photos/showphoto.php?photo=7861&si=lug&perpage=24

[monstaru]

don't overrthink it.it's only engineering.

[Phizinza]

Ford Courier 77-84 14 x 6

Nissan Pickup 73-86 14 x 6

I know these two should have the right offset..

I have a set of custom mags for the Courier on my car (15x6, though same offset) and a set of the Nissan 14x6's with some M/T's. I use both on my Brat.

Perfect offset if you don't want your tires sticking out..

 

You want 23mm positive offset I'm pretty sure for a 6" wide rim. That should work just perfectly.

[froej25]

Ah, thank you Phizinza, that's good to know that those two will work. Do you happen to know what size tires are on both sets of wheels? Are the tires on the 15s really low profile for light off-pavement use, mainly gravel roads? We don't need short stiff highways that are going to force the suspension to soak up every bump and impact, Michigan roads are bad enough already without magnifying the effect. When you say M/T, is that Mud-Terrain?

 

And no, I certainly don't want the tires to stick out, I doubt my brother does either. Too much strain on the hubs, for one thing, and its better to have a tire that tucks into the fender, not eats it.

 

I think the Nissan is going to be the way to go; I've only ever seen a Ford Courier once in my life, I'm sure the ones sold in Michigan succumbed to rust long ago. Hopefully there are still a few older Nissans; I'll still try to figure out if the D-50 / Mighty Max wheels will work, there will be a lot more of those available in Michigan because of Chrysler workers.

[Reveeen]

I've only ever seen a Ford Courier once in my life

 

Ford Courier = Mazda

 

You aren't missing much.

 

D-50 / Mighty Max = Mitsubishi

 

There are also some white spoke type trailer type rims available in 6x5.5" bolt pattern, various sizes and offsets, I'm using a 6.5X16 on my Subaru with a lift.

 

The hubs have plenty of "meat" for drilling, and should be ok as far as not going through an ordeal, or worry. These are not heavy vehicles.

[Phizinza]

The 14" wheels run 27x8.5R14 Kumho Mud Terrains. Well they measure 26.4x7.75, but you get the picture.

The 15" mags run a 215/60R15 (25.5" OD) directional street tyre. I don't think you'd be able to run these on a stock ride without bashing the wheel well a little in the rear of the front guards. Maybe some 205/55R15's would fit in nicely? Although that's getting a bit low profile for what you need by the sounds of it.

The reason I picked 215/60R15's was because it was the maximum width I could have on a 6" wide rim and I wanted some beefy tire wall to show. I likes me tire wall nice and beefy

[froej25]

Ok, here's what I come up with regarding tire sizes:

 

Tire size_______ Sidewall height___ Overall height

185/70-13______ 5.1"____________ 23.2"

195/65-14______ 5"______________ 24"

195/60-14______ 4.6"____________ 23.2"

215/60-15______ 5.1"____________ 25.2"

27x8.5-14______ 6.2"____________ 26.4"

225/55-17______ 4.9"____________ 26.7"

 

Of course, this is really only an estimate, the overall height and diameter aren't always the same, varies from manufacturer to manufacturer and tire to tire, but it should be close. The 185/70-13 is the stock size; I still have to figure out from my brother exactly what he wants to use the BRAT for, but I think its going to be about 90% paved, 10% gravel, so the emphasis will be on street performance. The 195/60-14 is the leading candidate, the loss of sidewall height isn't that bad, and the overall height is very similar. Obviously, the suspension is dramatically different, but the 255/55-17s on my Outback have pretty good performance characteristics, and are similar in sidewall height. The 215s and 27s are too tall for this application, and I think the 195/65s are going to be too tall as well, but would be good for more off-road oriented work. That's what I'm thinking at this point anyway.

 

Are the wheels for trailers adequate for this application? I'm sure they're strong enough vertically (some of them anyway), but what about lateral loads on the front wheels from turning? I'd rather use the truck wheels; if we can find them anyway. I'll keep the trailer wheels in mind, but it'll be a last resort; it looks like you can pick up Nissan wheels for about $15 each, even figuring the cost of getting them powder coated they shouldn't be too bad. Thanks for the input...

[Reveeen]

Are the wheels for trailers adequate for this application?

 

Each and every situation has to be looked at on it's own merit. I am using trailer wheels rated for 1 ton (2000 lbs) each, with a total vehicle weight of 1030kg (2200 lbs), I *think* i am within the limits of safety.

 

Personally I like Toyota wheels, but none were available, and white spoke wheels match my white car.

[Phizinza]

When looking at it, most of the 2WD jap trucks have the right offset you are after.

But there is no guarantee with this stuff. Old cars get different parts all the time.