OBX Helical LSD
#161
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Had my diff put in today. I didn't have any of the issues that Dustin had, but I did have a new (small) one. The ring gear bolt holes on the diff needed to be reamed out a bit to actually fit the shoulder on the bolts.
Other than that, the runout was fine and the diff measured up fine with a few adjustments.
Putting it back in tomorrow.
Other than that, the runout was fine and the diff measured up fine with a few adjustments.
Putting it back in tomorrow.
#163
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Well I'm happy to report that after an hour and a half of beating on this thing doing donuts, drifting, 4k launches (Rotrex'd and it's about 4PSI at 4K) and lots and lots of twisty roads it is doing great. It locks very well and much better than my old Maruha and I might even say my old old T1 Torsen. I'll be taking it to a hillclimb this weekend and will report back after then as well.
#164
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Join Date: Jan 2007
Location: Los Angeles, CA
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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...
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...
#165
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Well I'm happy to report that after an hour and a half of beating on this thing doing donuts, drifting, 4k launches (Rotrex'd and it's about 4PSI at 4K) and lots and lots of twisty roads it is doing great. It locks very well and much better than my old Maruha and I might even say my old old T1 Torsen. I'll be taking it to a hillclimb this weekend and will report back after then as well.
#169
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So I took my diff apart, deburred everything (gears installed correctly, had 12.9 grade bolts, but the belleville washers were complete junk) and bolted it back together with loctite 242 to 35 ft-lb.
Inspecting it on a crankshaft balancer, I found that the ring gear flange is out 0.007" in concentricity and about 0.005" on the ring gear mounting surface (with respect to the thrust bearing surfaces.) FML![facepalm](https://www.miataturbo.net/images/smilies/facepalm.gif)
I'm considering just installing it and messing with the ring gear orientation to see if i can get the backlash in spec. Any insight there?
Inspecting it on a crankshaft balancer, I found that the ring gear flange is out 0.007" in concentricity and about 0.005" on the ring gear mounting surface (with respect to the thrust bearing surfaces.) FML
![facepalm](https://www.miataturbo.net/images/smilies/facepalm.gif)
I'm considering just installing it and messing with the ring gear orientation to see if i can get the backlash in spec. Any insight there?
#177
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Well mine has another autox under it's belt now with a bunch of launches and it's still holding up great. I had to get rid of a flat spot on my tires from a moron friend locking my front tires up in the stop box. Swapped fronts to backs and it laid two nice fat long strips from a 5-6k launch banging off the limited. I think if it were to break it would have already. I'll be adding some more power soon right now I'm around 230whp.
#178
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Given the OEM TorSen on my '99 seems fubar'd, (reverted to an open diff over its 92k miles) I've read this with interest.
Only issue (other than living on the 'wrong' side of the pond - but they'll ship here), is that I have a 6 speed box. All the eBay ad's state it's for a 5 speed...
Anyone fitted one to a 6 speeder?
Only issue (other than living on the 'wrong' side of the pond - but they'll ship here), is that I have a 6 speed box. All the eBay ad's state it's for a 5 speed...
Anyone fitted one to a 6 speeder?
#179
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Join Date: Jun 2006
Location: Warrington/Birmingham
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If it broke, the diff wouldn't work anymore period.
Gearbox is irellevant btw. The LSD fits in the differential, not the box.
#180
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Given the OEM TorSen on my '99 seems fubar'd, (reverted to an open diff over its 92k miles) I've read this with interest.
Only issue (other than living on the 'wrong' side of the pond - but they'll ship here), is that I have a 6 speed box. All the eBay ad's state it's for a 5 speed...
Anyone fitted one to a 6 speeder?
Only issue (other than living on the 'wrong' side of the pond - but they'll ship here), is that I have a 6 speed box. All the eBay ad's state it's for a 5 speed...
Anyone fitted one to a 6 speeder?
To make my useless post now somewhat productive: nobody ever commented on the behavior of the diff vs. the stocker. EX: the rx7 diff is stronger but drives like ****.