installing 14 mm wheel studs in vw brake drums

manxvair · Post by **manxvair** » Fri Oct 29, 2010 7:30 pm

I'm planning on installing 14mm press in wheel studs on my front 5 lug ball joint drums.
(1) does anybody know what size drill to drill out the current 12mm holes?
(2) is there anything that needs o be done to the inside of the drum for the stud to clear the brake hardware?
Thanks in advance for any helpful tips

jsturtlebuggy · Post by **jsturtlebuggy** » Fri Oct 29, 2010 8:16 pm

If using the SwayAway one that say SAW or the KarTek one's they use a 9/16" drill bit.

The EMPI, BugPack, and nonames ones use a oddball size bit. It not commonly available in a hardware store. I found out they are larger diameter and cracked a drum years ago trying to press one in.

If you have acess to a mill you can spot face the drum on the inside where the head of the stud sets. Other wise you will most likely need to grind/sand down the head of the stud to clear the brake shoes. You can also grind/sand the edge of the shoes for clearance.

I prefer to use a press to install the studs, but they can be pounded in. Just make sure to support the drum in the area around where the stud is coming through. A socket or piece of tubing or pipe. Even block of wood will work. No support and drum could break while putting stud in.

towd-dude · Post by **towd-dude** » Fri Oct 29, 2010 8:49 pm

When I put studs in my VW drums it was necessary to grind off some of the stud head because I had a raised area near the stud holes. This was only necessary on the front drums the rears had no problem. I used a 9/16 bit with EMPI studs. They went in tight but I used loctite anyway. I have also punched them in with 5lb hammer. Doing it that way takes 2 beers per drum... But well worth it when your changing a tire on the trail, especially a big rear one....
Bob

MyBlueBuggy · Post by **MyBlueBuggy** » Sat Oct 30, 2010 3:34 am

I cannot remember what size drill I used to clear out the threads of the 12mm lugs in my front (four lug) drums. It may have been a 1/2" bit. I do know that to drill out the holes to the final size I used a 9/16" bit then finished the hole using a 37/64" bit. I found it at my local ACE Hardware. It's not much bigger than the 9/16" but it's the size you need to do the job correctly.

I used a drill press to make sure the holes were straight and true. I also used a hydraulic press to gently push the new studs in. Using a hammer can lead to too much stress in an unwanted area of the drum and lead to a potential break. I did not have to clearance anything of the drum either.

The only problem I had was after I had finished the job I discovered the studs were a bit shorter than I really wanted. They work, but I will replace them in the future.

BuggyBob · Post by **BuggyBob** » Sun Oct 31, 2010 4:33 pm

I used a 9/16" to drill out the threads then a 5/8" and only drilled 1/3into the hole from the inside of the drum. I set the studs in and mounted an old rim on the drum and sucked the studs in using an electric impact driver. Checked for clearances and grinded where needed.

towd-dude · Post by **towd-dude** » Mon Nov 01, 2010 11:10 pm

Bob,
Good idea using an impact to pull the stude in but why the 5/8, seems to lessen the material for the stud to hang on too....?
Bob

Tom-Kathleen · Post by **Tom-Kathleen** » Mon Nov 01, 2010 11:58 pm

It takes 2 things to make studs work. I have machined blank rotors for studs in the past.

#1 is an interference fit. I shoot for .010-.015 and make the hole fit the size of the splines on the studs, minus .010-.015. I have been able to draw studs in using lug nuts in the past, as long as the threads are lubricated.

#2 is a flat and "square" surface for the head of the stud to sit on. If this surface is not square to the hole and the wheel mounting surface, the stud will not sit perpendicular to the hole and you won't be able to get the wheels on.

Tom

manxvair · Post by **manxvair** » Thu Nov 04, 2010 12:30 am

Ok so the 37/64" drill bit was the right call, the 9/16" still left it real difficult to get the stud in. I had to grind down the head of the stud some but it still wasn't enough to clear the spring retainer cups. I am now having a buddy from work with a lathe take the head of the studs down so they are all equal, he then will turn down the inside face of the drum to help.
Thanks again for all the tips.

MyBlueBuggy · Post by **MyBlueBuggy** » Thu Nov 04, 2010 3:10 pm

I'm curious to see if any one who has 4 lug drums has had to grind the heads of the studs. I did not and I wonder if the issue is only with the 5 lug.

manxvair · Post by **manxvair** » Thu Nov 04, 2010 4:18 pm

No it isn't an issue on the 4 lug configuration. On the 5 lug setup the lug holes go over the brake shoes/retainers/adjusters/wheel cylinders this is where the clearance issue is. This issue also exists if the lug bolt is to long going thru the drum. On the 4 lug the holes aren't located over all this hardware.