4 5/8 bolt pattern? what? help?

2 years ago when this thread started the bolt pattern checkers were only $4.00.

 

Drop biscuits.

 

OK I now know that this is a 2 year old thread and that folks are still argueing about bolt circles some with little understanding of what a bolt circle is.

Tha said and in Re of paperdogs comment here. A lot of late model cars actually us a metric bolt circle. That would be late model American cars.

Let us ***ume for arguements sake that one decides to use an '80s model S-10 rear because they are narrow.

if you throw a 5 on 4.75 GM steel wheel on it you will notice that the lugs seem to drag a little. No biggy it is just something a little off at the factory, you snug your lug nuts down and go on with life. Now the same rear end with a cast wheel either aluminum or magnesium that takes a shank style lug nut. The wheel goes right on no problem, the problem comes when you go to put the lugs on. It canot be done unless you take a rat tail file to the jug holes and move them toward the center about 3/32 of an inch. Actually it would be better to use a bridgeport and an end mill but for backyards sake we are using a rat tail file.

When we are swapping in late model stuff to our traditional rods we need to bear in mind that a lot of late model stuff is metric. Perhaps that is another good reason to use old obsolete parts instead of the latest street rodder trend.

 

Nothing really needed to be said after this post. It is exactly what I see. Had the holes been half inch your ruler in effect would have "slid" to the right and the half mark would have been centered over the second hole showing 5 on 4/5.

 

Almost everything pre-21st-century from Detroit was inch-dimensioned unless it was foreign-sourced or foreign-designed. Ford is 5x4.5 (or 5x4.25/5x108 in a couple applications), GM 5x4.75, etc.

Most late GM cars are 5x115, the Cadillac Catera (Opel Omega MV6) is 5x110, many GM FWD products were 5x100.

One key consideration is that even when the bolt pattern is inch-dimensioned you will often find metric STUDS which can be slightly different in diameter (e.g. 12mm vs 7/16 in your S-10 situation, etc.) and the shape of the lug-nut taper can also differ. You'll need lug nuts with the appropriate thread for the stud and appropriate straight or ball taper for the wheel.

In some products that are foreign-sourced or foreign-design you have a slightly different situation - for instance, the Australian Holdens sold as Pontiacs (G8, GTO) are actually 5x120mm (as are 5-lug BMWs) though in practice 5x120mm and 5x4.75 (5x120.65) are routinely interchanged.

Wheel centerbores can differ all over the place, BMW's used a couple different centerbore sizes seemingly dependent on which vendor provided the hubs/bearings for that particular model, centering adapters are easy if you've got a lathe, sometimes you need to bore out the wheel a bit though...

 

well i thought of a little filing to get the shank lugs seated but figure i would be creating a imbalance .. along with bias tires and innnertubes it was way too many possible problems .. i have since this episode found a metric bolt circle tool thingie and yes the metric size is very close to the 4.5 circle .... i suppose the aftermarket spoke wheel had multiple applicatins but i never found where they where really gonna work

 

Bad example, 80s S10 is 4.75", but has metric studs. GM specs say it is 120.65 mm bolt circle.

Better example, 2000 Pontiac Bonneville is 115mm or 4.527". 2000 Misubishi is 4.5" or 114.3 mm.

 

4¾" = 120.65mm exactly.

BMW bolt circle is 5 x 120mm. I don't know anything else that uses that pattern. It's therefore 0.325mm (.013") off a Chevy bolt pattern. That's file territory, I'd say.

4½"/115mm is pretty much the same difference. GM's is the odd size here, though. 4½" or 114.3mm is one of the most common pcds out there, be it four- or five-stud.

 

Thank you SIR, I'm glad you and some of the other folks understood. Have a great day, TR

 

This is a good example of why I dont post more on this board. To many people telling people what they think.

FoMoCoPower the comment you made about Charlie chops was out of line. Charlie chops was actually correct with his statement.

5 on 4 3/4

First number stands for how many lugz. 5

Second number stands for the diameter of a complete circle that intersects the center of all lugz 4 3/4 diameter

Markyac No limit sells a mustang II rotor that has two (2) bolt patterns 5 on 4 3/4 And 5 on 4 1/2
So why would you state something that is not true. Your misleading your fellow hotroders.

I know this board is a lot of fun but let's try a little harder to post correct information.