Why doen't Modern carry OBX LSD's anymore?

TN.Frank · Post by **TN.Frank** » Mon Dec 17, 2007 3:46 pm

I noticed on MP's web site that they've only got the Phantom Grip and the Quafi LSD diffs available, why did they drop the OBX or have they just not added it to the new site yet? That was the one I wanted to go with since it's just over $500 which is over half what the Quafi is.

Post by **racer12306** » Mon Dec 17, 2007 3:52 pm

I'm sure there are other places to get the OBX diff.

I believe there are a few little things that need to be done to it in order for it to be reliable. I think this is covered over at neons.org in the driveline section.

03blackrt · Post by **03blackrt** » Mon Dec 17, 2007 4:19 pm

http://turbosunleashed.com/shop/product ... cts_id=306

TN.Frank · Post by **TN.Frank** » Mon Dec 17, 2007 4:38 pm

Yep, I did a google and found out that you need to replace the washer and bolts to make it work right. Also, you need to honne out where the axles go so they'll fit right. Still, I'd rather save a boat load of cash and do some work on the diff my self then spend $1300 or so on a Quafie diff. Now if money wasn't a problem I'd go with Quafie but then I'd probably go with something other then a Neon too, LOL.

gilly02le · Post by **gilly02le** » Mon Dec 17, 2007 6:37 pm

the obx offers a lifetime warranty too, thats pretty nice.

TN.Frank · Post by **TN.Frank** » Mon Dec 17, 2007 6:46 pm

Even almost stock my car spins the one tire quite a bit if I try to get into it from a dead stop. I really need an LSD diff and I'd like to add 3.94's too as long as I'm getting it taken apart to add the LSD. That should help with 1/8th mile times when I take it to the track in March. I hope I can find a job so I'll have the money to get everything done by then. They're going to close 3 plants here in Crossville so they'll be a lot of people out of work in the area.

INVUJerry · Post by **INVUJerry** » Mon Dec 17, 2007 7:30 pm

OBX's barely work most of the time. I'd either go phantom grip or Quaife.

esteinmaier · Post by **esteinmaier** » Mon Dec 17, 2007 9:29 pm

I'm gonna have to go ahead and disagree with you, Jerry. The failure points of the OBX have been identified, and there are definitive replacement parts that make it theoretically just as good as a quaife. In that link above, you can add $75 to the order to have them prep it for you so you can just adjust the preload and drop it in.

TN.Frank · Post by **TN.Frank** » Tue Dec 18, 2007 8:07 am

And that brings up my next question. How hard is it to set up a diff in a FWD car? I know in RWD diffs you've got to shim up the pinion and adjust the ring gear/carrier but from the way a FWD transaxle looks there's really no way to adjust the pinion, so all you need to do is adjust the ring gear/carrier to the proper mesh with the pinion and that's about it or am I missing something?

turbodudey · Post by **turbodudey** » Tue Dec 18, 2007 1:13 pm

Not even that. There isn't any adjustment between the output shaft and the ring gear. You just drop the new diff in and go.

The one thing that does need adjustment is the diff bearing preload. You just have to shim the bearing race to achieve the proper turning torque/ bearing preload.

TN.Frank · Post by **TN.Frank** » Tue Dec 18, 2007 1:32 pm

turbodudey wrote:Not even that. There isn't any adjustment between the output shaft and the ring gear. You just drop the new diff in and go.

The one thing that does need adjustment is the diff bearing preload. You just have to shim the bearing race to achieve the proper turning torque/ bearing preload.

Wow, that sounds way easier then with a RWD diff. where you've got to set the pinion depth and then put shims in each side of the carrier to set the preload on the ring gear to pinion.
So it's pretty much a drop in with shims being used on either side of the carrier to set a bit of preload. Well, heck, I'll probably install the diff my self then and save some cash. Is there like a shim pack you can buy or does it come with the diff to set the preload? Also, would it go into details in my Haynes book or is there some other book I could get to explain it in more detail?

turbodudey · Post by **turbodudey** » Tue Dec 18, 2007 1:43 pm

The Factory Service Manual is the best book to get. It covers everything you'll ever need.

A new diff will not come with shims. You can buy them individually for about $3-4 each. You'll also need new bearings, ring gear bolts, axle seals, speedo drive gear, and a few other things...

More info, part numbers, and a how-to:
http://dope.dhs.org/car_stuff/Tech_Arti ... ap_How-To/

TN.Frank · Post by **TN.Frank** » Tue Dec 18, 2007 2:25 pm

turbodudey wrote:The Factory Service Manual is the best book to get. It covers everything you'll ever need.

A new diff will not come with shims. You can buy them individually for about $3-4 each. You'll also need new bearings, ring gear bolts, axle seals, speedo drive gear, and a few other things...

More info, part numbers, and a how-to:
http://dope.dhs.org/car_stuff/Tech_Arti ... ap_How-To/

Excellent web site, lots of pics, that makes it easier for me then just words. Thanks.

What about gears for the diff. Do I have to go Mopar or does someone like Motive make a replacement set? I'd like 3.94's I guess since it's already got 3.55's and I know my truck ran better going from 3.55's to 4.10's.