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Knurl Dia. of Lug Stud Questions

CDA 455 II

CDA 455 II

ANFAQUE2
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I'm looking to replace the lug studs in my '87 Ford Sterling 10.25 dually axle.


Rockauto lists lug studs with knurl dia of 0.622".

Amazon lists lug studs with knurl dia of 0.677".


Is this a big dia difference/deal big?

Or will one just fit tighter than the other?

Or will one fit and the other won't?

DOES IT MATTER / WILL EITHER KNURL DIA WORK?


For reference:

lug studs.jpg
 
Yes it matters.

If the hubs had .622 in them factory .677 is way way too tight.

I gave my hubs .003 - .005 press and I predrilled the hubs and rotors the correct hole diameter for those knurls even went beyond and used a spiral reamer to get the holes perfect.
 
Are they the same part number?

i buy a ton of parts from amazon but don’t rely on them for specifications or “part fitment “ simply plug in a part number from rock auto to see how it’s priced compared to RA/autozone/ eBay etc.
 
PAE said:
Yes it matters.

If the hubs had .622 in them factory .677 is way way too tight.

I gave my hubs .003 - .005 press and I predrilled the hubs and rotors the correct hole diameter for those knurls even went beyond and used a spiral reamer to get the holes perfect.
Click to expand...


So I should trust Rockauto's specs?
 
https://tech.arp-bolts.com/wheel-stud-fit.php

ARP Wheel Stud Knurl Fit

Wheel Stud Hole Sizes and Proper Interference Fit for the Knurl


Our OEM replacement wheel studs are designed to press-fit into the original hole in the OEM hub (preferably with a hydraulic press, as using a nut can create problems).

If you are using one of our kits in another application, the hole should be checked to ensure it falls within the correct tolerance to allow for the proper amount of interference, so that the stud won’t spin in the hole. For steel and cast iron hubs, the hole should be 0.006-0.016˝ smaller than the Knurl Diameter. For aluminum hubs, the hole should be 0.010-0.016˝ smaller than the Knurl Diameter. As a courtesy, we have provided the closest standard drill size that will provide a hole in that range.

If the hole is larger than the tolerance listed for the material, then the studs should not be used with that hub. The interfernce fit will not be tight enough and the stud could spin in the hole.

If you need to drill out the holes in your hub, the holes must be kept perpendicular to the face of the hub. If you do not have a fixture that clamps to the hub to guide the drill straight, use a setup similar to the one in the image at below. (A hand drill will not produce satisfactory results.)

All ARP wheel studs have an underhead radius. Each hole must be chamfered 0.025˝ to clear the underhead radius and prevent stud failure.

wheel-stud-drill-hub-clear.jpg
© 2020 Automotive Racing Products, Inc., All rights reserved.
 
Twankie said:
Are they the same part number?

i buy a ton of parts from amazon but don’t rely on them for specifications or “part fitment “ simply plug in a part number from rock auto to see how it’s priced compared to RA/autozone/ eBay etc.
Click to expand...
Negative


Two different brand names
Rockauto: PTC #97224

Amazon: Dorman #610-303


Would Rockauto part#/specs be accurate/reliable?
 
PAE said:
Hell no, use a measuring instrument to know what the knurl OD is.

IMO rock auto is hack, bottom feeder when it comes to quality auto parts.

But I have Dom Periogn taste and Budweiser budget.
Click to expand...


Ok; nOOB question:
Can I go to a Ford dealer's truck-parts department and get what I need?
 
IMO that would be the best or maybe 2nd to the correct ARP stud.

CDA 455 II said:
Ok; nOOB question:
Can I go to a Ford dealer's truck-parts department and get what I need?
Click to expand...
 
Knock one of the existing studs out and measure it..........................and measure the hole since you just knocked a stud out.
 
gt1guy said:
Knock one of the existing studs out and measure it..........................and measure the hole since you just knocked a stud out.
Click to expand...

That was the first thing I thought of. :o


But the threads are so shot I'm concerned that if I remove the lug nuts again I wouldn't be able to get them back on.

That may end up happening anyway.....
 
Dorman catalog can get you specs and the Dorman replacement part number- https://www.dormanproducts.com/flipb...e-hardware.pdf

I followed the ARP recommendations posted earlier when changing studs on front axle hubs and was good with ~0.010" press fit. They were tight, but pressed in fine with no cracking. If jsut replacing, the studs, check the catalog or hit up the dealer.
 
YJBrian said:
Dorman catalog can get you specs and the Dorman replacement part number- https://www.dormanproducts.com/flipb...e-hardware.pdf

I followed the ARP recommendations posted earlier when changing studs on front axle hubs and was good with ~0.010" press fit. They were tight, but pressed in fine with no cracking. If jsut replacing, the studs, check the catalog or hit up the dealer.
Click to expand...


Because I'm poor / don't own a press / don't want to break down the hub assembly; I'm going to use a stud installer method.


Unless that's an absolute no-no. :confused:
 
Its not like you havent been exposed to the word on that issue.

You are looking for absolution before the fact.

The blurb I posted from ARP said how its to be done, while I think they are a little over the top on their interference fit spec (read too tight) they say to use a press and to relieve the studs radius as well.

You have your INSTRUCTIONS so go do it and dont be a cheap bastard if you dont own a press,

pay someone to do it correctly so you dont kill a busload of nuns.


CDA 455 II said:
Because I'm poor / don't own a press / don't want to break down the hub assembly; I'm going to use a stud installer method.


Unless that's an absolute no-no. :confused:
Click to expand...
 
IMO, 0.010 is a bit tight. The minor should be metal to metal, then the knurl can be 0.002 to 0.005.
 
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