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Suspension, Brakes, Drivetrain discuss the wondrous effects of boost and your miata...
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OBX Helical LSD

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Old Apr 30, 2011 | 06:43 PM
  #121  
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How much would you be charging for a reworked unit and would you be checking (and fixing if needed) everything true?
Old Apr 30, 2011 | 08:04 PM
  #122  
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I'd like to try this baby out before I sexplode my torsen.

The plan is for me to do all this reliability stuff (or pay a fellow member to do it if the price is right hint hint) and then crayon I mean cryotreat and polish all the goodies at Liberty's Gears like I did with my r&p.
Old Apr 30, 2011 | 08:11 PM
  #123  
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[QUOTE=dustinb;721286] Holy ****, the OBX diff.....Sweet monkey jesus I've never laid rubber down like that. There was a party going on in the rear end.
[QUOTE]



I'm sorta drunk.
Old Apr 30, 2011 | 08:23 PM
  #124  
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I have never physically touched one of these OBX units yet, so I have no idea what it will take. I'd probably charge about 100 bucks I'm thinking, unless it took like a **** ton of time.

My service would simply be a total tear down, replace the washers with the recommended preload, and going through the whole case and deburring and either dremel+ polish or glass bead as needed. I have a cabinet for media blasting, its pretty simple stuff.

I just have to see if its worth my time and if I have time to do it. I've got some experience doing projects like this, but they sometimes turn into time vampires. This seems super straight forward.

Keep in mind, i work **** tons of hours, and don't need money, but I sure as hell needa hobby... I live in my RV, and I work about 90-120hrs a week 7-days a week for about 2 months at a time...
Old Apr 30, 2011 | 08:54 PM
  #125  
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My diff is sitting at a package holding place in WA. Going to head down on Monday to grab it.

Also found this for those of you who want to install it yourself. Looks like the Miata diff is VERY easy to adjust. NO SHIMS!!


With pictures...

http://www.miata.net/garage/diff_rr.html
Old May 1, 2011 | 02:00 PM
  #126  
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So DustinB any more insight? Happy with it? Have you had a chance to do some launches yet? How about a mid-speed corner, driving for grip like you were on a track?
Old May 1, 2011 | 06:05 PM
  #127  
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Yes please do some 7000RPM 12psi sidestepping clutch dumps asap please and report back. thax
Old May 1, 2011 | 09:58 PM
  #128  
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Lol sorry guys, I've been out of town with my wife and not in the miata. I'll get some solid driving done tomorrow. Maybe make a video of a few launches.
Old May 2, 2011 | 04:15 PM
  #129  
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FML, so HARD to get these bolts out. There is no where to grab onto the housing to get any torque on it. I need air.
Old May 2, 2011 | 04:33 PM
  #130  
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Did you put the diff in a vice? There are spots on the diff to put it in a vice that will not damage the case.
Old May 2, 2011 | 04:45 PM
  #131  
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Originally Posted by falcon
FML, so HARD to get these bolts out. There is no where to grab onto the housing to get any torque on it. I need air.
I took mine out with my big torque wrench. I also put it in a vice but wrapped it in cloth.
Old May 2, 2011 | 04:45 PM
  #132  
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It would help if I had one...

I'm just going to get my air gun.
Old May 2, 2011 | 04:54 PM
  #133  
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So I just measured the place Dustin had an issue with. I measured at each bolt hole all around the diameter. It fluctuated from mostly .398 to .396 on a few of them. I guess .002 is fine?

This is how I measured. Would this be sufficient? Is this how a machine shop would measure it?

Old May 2, 2011 | 07:35 PM
  #134  
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A machine shop would use a surface plate and a dial indicator to see how "true" the the mating face of the ring gear is.
Old May 2, 2011 | 07:52 PM
  #135  
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It's not so much the thickness, but the runout on the surface.
Old May 2, 2011 | 07:56 PM
  #136  
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I would still bring it to a machine shop. That's just checking that the thickness is the same all the way around.
Old May 2, 2011 | 08:30 PM
  #137  
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So here's a little in-car action. Not sure if it helps anything.
Old May 2, 2011 | 08:33 PM
  #138  
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You need to lay it flat like you have it, and spin it with a dial indicator on the machined surface. The little needle will move back and forth. On the low side, set the dial indicator to 0. Then go to the high side. This needs to be less than .002 I think, or whatever was mentioned above.
Old May 2, 2011 | 08:47 PM
  #139  
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Right past Western Speedway I see..


Thanks Curly but I think I'm just going to bring it to a shop to be sure.
Old May 2, 2011 | 08:50 PM
  #140  
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Originally Posted by falcon
Right past Western Speedway I see..


Thanks Curly but I think I'm just going to bring it to a shop to be sure.
Hahah, yup. Some guy came racing out in his minivan and told me to find another parking lot.



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