Wheel PCD confusion please help?

[snakesaway]

Hi all,

I want to order some ET wheels AC-III 17 inch for my Evans running jag hubs front and rear. My 2 front wheels on the car have manufacturer labels saying they are 5/114.3mm PCD. One of the back wheels says 5/4.75. I have measured the PCD using the following method, http://www.etmags.com/pdf_download_d...rn_diagram.pdf, and I get 114.3mm. I looked at the chart on the worksheet and the PCD closest to this is 4.75" or 114.74mm .54 mm larger to my mind this would make quite a big difference overall. I am lead to believe by ET wheels that the standard Jag PCD in 114.74mm or 4.75". I can't find this information on the web any where. Every time I search for this info I get a PCD of 120.6 mm. So I am suitably confused as to what PCD I should be ordering.

Any help would greatly appreciated.

Andrew

[xb-60]

Originally Posted by snakesaway

Hi all,

.... I looked at the chart on the worksheet and the PCD closest to this is 4.75" or 114.74mm ....

Andrew,
4.75" is 120.65mm

Cheers,
Glen

[deano59]

jag and hq holden are the same but commodore is just a smidge bigger some people use them but they pull the studs out on a angle and can break them look for the pcd on commodore and see if thats the same as your back rims . i presume the back end is jag ?

[snakesaway]

Originally Posted by deano59

jag and hq holden are the same but commodore is just a smidge bigger some people use them but they pull the studs out on a angle and can break them look for the pcd on commodore and see if thats the same as your back rims . i presume the back end is jag ?

Thanks Deano that's interesting because I was told by a jag wrecker that the PCD is the same as Ford. Yes the back end is Jag and it measures the same as the front 114.3mm between 2 adjacent studs not 2 studs next too each other. I did adjacent stud as that is how et wheel said to measure in their doc on the website. I have seen some methods that measure between to studs next too each other and then multiply by 1.701 I think.

[leroy17]

Jag is the same as Chev (4.75), not ford. And as Dean said, Commodore is slightly different.

Re-drill Jag hubs to ford pattern, there is room on the back. But, its easier to get the right wheels in the first place.... trust me.

[Mrs flatchat]

HQ Holden , Chev, Jag 5 stud = 4.75"pcd (120.65)
Commodore , BMW 5 stud =120mm PCD
Ford , Toyota 5 stud = 4.5" PCD (114.3mm Pitch Circle Diameter)
Just to mention a few common ones

double post POS

[Mrs flatchat]

HQ Holden , Chev, Jag 5 stud 7/16"or 1/2" UNF or M 12x 1.5= 4.75"pcd (120.65)
Commodore , BMW 5 stud M 12 x 1.5 =120mm PCD
Ford , Toyota 5 stud 1/2" UNF = 4.5" PCD (114.3mm Pitch Circle Diameter)
Just to mention a few common ones

[Dominik]

Here is a nice site listing all PCDs:

Alloy Wheel Fitment

You can't use 120mm PCD wheels on 4.75". Unless you use knock off adapters who compensate for that with a smaller diameter pin drive. i.e 18 mm instead of 19 mm outside diameter.

[07cob]

Andrew

If it helps, the exact PCD can be calculated for a 5 stud wheel as follows:

1. Measure the distance between centres for two studs with one between them, as per the instructions in your link (you have already done this and got 114.3mm!)

2. PCD = your measurement x 1.0514622, or if you have one of those fancy scientific calculators or a slide rule, PCD = your measurement x sin72*

So your 114.3mm would be a PCD of 120.18mm or 4.73", which I would suggest, as you point out, is quite different to 4.75".

How did you make your measurement? Could there have been some small error? You would only need around 0.44mm error to account for the difference, if they are indeed 4.75mm PCD hubs. If they are actually 120mm PCD then you would only need 0.16mm error.

The only other thing I can think of is if you are using verniers, be sure that neither tyne sits inside one of the threads. Use the inside section of the callipers to cover more than one thread on each stud.

Good luck

Geof

[cycleguy55]

Here's measurement information from Tire Rack, including the following note: "When measuring a 5-lug wheel the measurement is only an estimate unless accurately measured using a bolt pattern gauge. A bolt pattern gauge is a specialty tool and is not widely available." https://www.tirerack.com/wheels/tech....jsp?techid=92

Here's another view on this: "If your wheel has a 5-bolt pattern, measure from the BACK of one bolt hole to the center of the second bolt hole as shown in the diagram. You can also measure from the CENTER of one bolt hole to the CENTER of the third hole using a multiplier of 1.05 to find your bolt circle."

There's an illustration of this at the following link: http://www.wildhorses4x4.com/product...terns/tech_faq

[boxhead]

If you have Jag, and not modified, then you have 4.75"

[Baz]

I'm thinking of changing my 17" Vintage Pin Drives over to 15", so my 17's could be on the market in the not too distance future. Send me a PM if your might be interested and I will give you all the details including the tyres fitted currently and the back spaces. The Sumitomos will go with the rims as I will be getting Avon CRZZ's on my 15's. The reason for the change is I'm looking for a higher profile in the side wall. The 17" rims are as new.

Baz

[Dominik]

If you have a laser or water jet cut company nearby, get PCD templates cut from sheet metal. Probably $100 well spend for the rest of your life :-) Make a few spares for your friends.

I regret not having done this years ago.

[Ad Guy]

I have Jag running gear.

Holden PCD is the closest but not the same as Jag.

Don't forget about the hub. I couldn't seat Holden wheels from my VS as the Jag hub was too big.

[deano59]

Originally Posted by Ad Guy

I have Jag running gear.

Holden PCD is the closest but not the same as Jag.

Don't forget about the hub. I couldn't seat Holden wheels from my VS as the Jag hub was too big.

i def ran hq rims on my jag based car the only thing needed doing was the centre hole needed boring out in the mag once that was done they bolted straight on .

jag and hq/chev have the same pcd vs rims are different pcd to early holdens

[boxhead]

There is a difference from HQ (Imperial) to Commodore (Metric) it is minimal, but it is a difference.
Last thing I would want to do is put extra strain on wheel studs at any speed, less so cornering speeds coming into turn 1 at Wakefield.

[snakesaway]

Hi all thanks for you input would seem that the wheels that were on the car were Holden/HQ PCD therefore not quite the right wheels.. So I have ordered the team 3 wheels with the correct JAG 4.75 PCD, so all should be fine now i just hope no long term damage to the wheel studs has been done. i guess only time will tell.

Merry Xmas

Andrew