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6 Lug conversion Question. 140 vs 139.7


Subarocket
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I've read up as much as I can find about the 6 lug conversions for my hubs on a 92 Loyale. I have never found anything on the minute difference in the 6 bolt pattern to the 4 bolt and any affect it has. The subaru is 4x140 and from my understanding the 6 bolt is 6 x 139.7. I have rims from a Nissan Pathfinder but am unsure of the year. I have knocked out the 2 opposing lugs and when I bolt the remaining 2 into the rim I can notice that it is not seated perfectly, which I would assume would lead to an unbalanced tire. My car will be doing plenty of highway miles, does this warrant any concerns?

Also, the centre bore of the rim is larger than the "axel seats" on the hub. I have never heard of anyone using hub centric spacers to fill this void. This seems extremely important to me as that interface is supposed to bear the weight. Does everyone use these spacers and I just missed it?

All the help is appreciated. I am not an experienced car guy and am learning as I go so please be nice!

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its never been a Issue on the cars Ive run, now Im running large unbalanced  mud tires (27-30 inches)

your looking at .3 mm difference  split between two studs so .15 mm per stud, now as you tighten

both lugnuts down evenly those 2 studs will tilt a tad to compensate, when I redrill hubs I use a jig

I had lazer cut  which acuratly drills the other 4 holes in there concentric proper spot , no Ive never used spacers to compensate inner rim bore

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Your eyes picked up a .3mm difference? You're good!

I wasnt even aware of the difference initially when i did the conversion to my hubs, so I didnt look for it. Good thing too, it probably would've driven me nuts!

My $.02...As long as the holes are drilled properly, you will not notice any difference in how it rides.

Mine is smooth as butter, no matter how fast i take it. ("Fast" being a relative term, with my ea 1.8)

And though it used to be hubcentric...changing it to lugcentric makes no difference; one's as good as the other.

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Unless you mill them, your worry of a "minute" difference is moot. Asking someone in your country if there are engineering tests is probably going to be a valuable venture for you.

If you are simply just not searching, start.

Google is amazing.

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Thanks for the quick replies guys. Also keep in mind that I acknowledge I am taking a car from stock to home made aftermarket so there will be some sacrifices but I am more just checking to see tolerances and what thought processes go into these fairly routine mods.

As for centre bore and hub centricity, everything I come across really emphasizes that lugs are not meant to take weight. Lugs are only engineered for lateral forces apparently. With the majority of the lugs not factory drilled it makes question being lug centric even more.

http://tires.about.com/od/understanding_wheels/a/hub-centric-vs-lug-centric-wheels.htm

It also seems easy enough to find spacers. Are Pugs made with the same centre bore?

 

I'm surprised not everyone has noticed the .3mm difference. To evenly split that difference between two studs seems difficult to me as the slightest torque difference would cause it to shift into the sweet spot of one lug. This then makes me curious as to the true centre when drilling for the other studs. Axel spacers could help with that. 

Scott, does your jig centre you for a 1/16" pilot hole or does the jig completely stop the bigger bit from wandering?

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I have run a six lug conversion for several thousand miles and others have as well.  On my hubs the centering ring on the rear and tabs on the front are not present meaning the only way to center the wheel is the lugs themselves.  As long as the conversion is done correctly I do not foresee you having any issues.

 

12070_10200761694515738_1067491289_n.jpg

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Also, the centre bore of the rim is larger than the "axel seats" on the hub. I have never heard of anyone using hub centric spacers to fill this void. This seems extremely important to me as that interface is supposed to bear the weight. Does everyone use these spacers and I just missed it?

 

All the help is appreciated. I am not an experienced car guy and am learning as I go so please be nice!

 

 

 

 Believe it or not but the center ring on the Hub IS NOT LOAD BEARING.That ring is to center the wheels when they are being mounted by tire monkeys.There is a certain amount of slack in the lugs and the holes so if you just slap on a wheel and tighten it down without any pattern or care like a tire monkey would do the wheel might not be centered on the hub.If however you go slow and tighten the lugs in a star pattern then the lug nuts will center the wheel.The load bearing part of the hub is the FRICTION between the wheel and the hub from the CLAMPING FORCE of the lugs.If the center ring was load bearing the wheel would have to be pressed on the hub because any clearance at all would make the wheel not centered.

 

On 6 and 8 lug wheels hub centric locating rings are simply not needed as evidenced by the millions of vehicles with no locating rings of any kind.If you want further proof,most hub centric rings are NYLON and there is no way a couple mm's of nylon will support the vehicle weight.

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Scott and Uberoo, thanks for the replies. It's nice to just hear that people have thought about this stuff and the reasons for doing it the way they do it. 

Uberoo, what you say makes sense, it is just funny that it is the complete opposite of the information in the link I posted earlier (which is similar to other bits of info I have found).

When drilling the rear drums, is there any reason to weld the unused lug holes closed? Dust, salt, water? It seems to be a fairly sealed unit before and now there are 2 holes in it.

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When drilling the rear drums, is there any reason to weld the unused lug holes closed? Dust, salt, water? It seems to be a fairly sealed unit before and now there are 2 holes in it.

Some people weld the holes closed on the front and the rear, but i just cut the unused studs off, flush with the face of the hub.

Edited by spazomatic
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Monstaru, I am not clear on what I would be asking about engineering tests for? Canada is packed full of a plethora of different engineering tests and facilities that do them. My google list would be large. 

 

 

To pass tech for your vehicle licensing.

if you don't have that , then why are you worried?

The overall point is, your thinking to much.

cheers

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Subarus are among the easiest vehicles to work on, so pick up a wrench and have at it.In the off chance you fubar something everyone here will be glad to help you get back on track.Subarus are giant lego sets so don't be afraid to mix and match parts.IE the hatch in my sig was 81, with the front suspension from an 89 gl,the transmission from an 85 gl,the engine from a 91 legacy,and the rear axles from another legacy.The newer subarus are still just as much of a lego set because the engines readily swap over,same with the suspension ie outback struts on an impreza...

 

So like I said just grab a wrench and have some fun,and show us what ideas are in your head..What you come up might just be the next big thing in subarus,fingers crossed for long travel suspension :)

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Also keep in mind that I acknowledge I am taking a car from stock to home made aftermarket so there will be some sacrifices but I am more just checking to see tolerances and what thought processes go into these fairly routine mods.

 

I will be happy to address this.

 

Being as I was the first to do the 6 lug conversion. A lot of thought, contemplation, and measuring went into this. I researched wheel offset and widths. I verified lug size and length. I verified compatibility of the lug nut angles as well. If the wholes are drilled straight and true to the correct diameter and the correct wheel stud and nut are used. It is better and stronger than the originals.

 

Monstaru is correct that unless you have extensive vehicle inspect in your providence than you may be over thinking it. But, he only says this because he knows that it was heavily researched before it was first done!

 

Enjoy,

 

Ken

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Ken and Uberoo, thanks again for the great replies. I have turned more wrenches on my Loyale (and 2 parts cars) than any other car I've had but I can't say that it always ends up going well. Regardless, I have learned a ton. I am in the process of buying a rust free 92 loyale (unheard of in these parts) to replace my rust bucket one. I've got a lift kit and am in the process of 6 lug conversion. Lots of ideas for this one since it will be possible and worthwhile to work on because of the lack of rust. It will be used for skiing, biking and carpentry so I hope to do many interesting mods to make it functional, utilitarian and a bit of a camper.
 

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