Machined hub specs?

[1Low620]

I keep searching but am coming up with the same ghetto video of sock dude boring out titan wheels to fit 521/620's, and then replies of " just machine your hubs " My Q is, how much needs to be machined down? I have a machine shop I utilize at work and my guy there said he'd do them for free rather than boring out the wheels. That, and I'd rather do the hubs if I ever decide to trade out the 18" titans.

 

Again, I don't plan on boring the wheels out, just need some sort of reference for the turned down hubs.

 

Thanks!

[datzenmike]

Wouldn't you just measure the hole in the center of the rim and just turn your hub down to just a hair under that?

[1Low620]

Wouldn't you just measure the hole in the center of the rim and just turn your hub down to just a hair under that?

That's what I was thinking but wasn't sure if there was a sweet spot so to speak that someone has come across.

[datzenmike]

Some hubs center the wheel with a snug fit onto the hub... the lugs only hold it on. If this is the case with the 620, once turned the stock rims won't fit that way again. Maybe someone knows more about this.

[Rjawm]

Even if the 620 does, which I highly doubt, you could always use these to make up the difference.

 

http://www.justforwheels.com/hub-centric-rings.jsp

 

Hub centric wheels are a much more modern development.  Most pre 90's vehicles still used lug centric wheels.

 

 

Most people say to take it out of the rim because a rim is more forgiving of the removed material.  And it's a procedure that can even be acomplished with a Dremel in some cases. 

 

A hub if machined too much can be extremely dangerous.  Too much material removed can lead to failure due to the thinning of the material around stress areas.

 

 

Keep in mind, this is coming from someone that had a fellow Ratsun member, Mklotz, turn down the bearing race areas of some Toyota hubs to do a 5 lug swap, just trying to give you perspective, lol

[Eagle_Adam]

Last time I modded hubs I just used a grinder to do it while they were on the truck

[Charlie69]

PM Mike Klotz He turns newer hubs to fit wheels on the older trucks.

[mklotz70]

I've got a mid-year 720 hub on the bench.  The center nubs are 3.5" in diameter.  That should clear any of the stock steel wheels.  If you are using conical lug nuts, I don't think you need the hub centric rings.  If you're running rims that use lug nuts with shoulders on them, yes.

Edited May 25, 2020 by mklotz70

[1Low620]

Last time I modded hubs I just used a grinder to do it while they were on the truck

 

That was going to be my first step till my machinist offered to do them for free, figured it would be quicker too. Basically what I have gathered is just machine the ears,nubs, whatever people call them to match the flat surface of the rest of the hub? if that's the case, sounds simple enough. I just didn't want to give him any bad info and have to ship more hubs in.

 

3-5 years ago, there were a few off the beaten path wrecking yards in this area that had several 620's, went out yard hop'n today and wouldn't you know it, most were bought off the yards complete or finally sent to the crusher :sick:

[1Low620]

Eagle_Adam, how much did you trim down? I've read the FAQ page, looks like that rotor was machined all the way and then some. I don't plan on converting to discs, well any time soon that is, so I just want a definitive mark for what will work and be safe

Last time I modded hubs I just used a grinder to do it while they were on the truck

 

Here is with the hub on, did you just grind down enough and make it flush with the drum?

 

 

Or did you take any meat out of these two areas?

 

and

 

I'd rather not ruin a good working set of rotors on trial and error, and everything I keep reading seems like everyone with the info has done this for trucks with disc conversions. Just want to make sure its the same for both drum/disc.

 

Thanks guys!

[heretic]

On my 78' 620, I turned my D21 hubs down to the point that the center was small enough to just fit inside a modern wheel & stayed lug nut centric.

 

 

 

 

I would think that on your front drums you would only need to turn down the little "nubs" flush to the outside drum face as long as the center section (where the wheel bearings rest) is small enough in diameter at the base or face of the drum to fit inside your wheels. 

 

 

  

[1Low620]

Yeah the center portion on mine is small enough to fit inside the standard Titan bore, only thing that is interfering is the nubs..... Keep in mind this is all stock 73 620 suspension and the Titans are NOT bored out as of yet. I bet if I bored them out an 1/8th of an inch they would clear easily or just machine down the nubs to match the lip of the drums.

 

Back to scratching my head and think about what route to take here.

 

Thanks for the pics.

[heretic]

being that its the nubs, I would do what Eagle_Adam said & knock them down with a grinder & call it good. 

[1Low620]

being that its the nubs, I would do what Eagle_Adam said & knock them down with a grinder & call it good. 

Ran around today and actually found a few parts trucks that I can snag replacement parts from if needed, so with that being said when I got home, I decided to trim down the nubs. I got a 2nd set of eyes just to look over things before I took the grinder to them and it does appear the bearing housing was rubbing just enough jam them up, so I gently went around that and made enough room to fit.

 

 

and

 

 

 

buttoned everything up and the wheels spin nice and true ( well to the human eye ) should be good to go, now I just need to find a 4th tire, have them mounted and balanced, want to replace the stock bulged acorn nuts with some of the newer bulged lugs but we'll see, I have read you can use them but I don't wanna get too cheap here.

[heretic]

great job, looks good man.!!!