JMortensen Posted January 28, 2009 Share Posted January 28, 2009 Hey, whaddya know!!! Link to comment Share on other sites More sharing options...
cygnusx1 Posted January 28, 2009 Share Posted January 28, 2009 OBX Mystery clunks and washer disintegration possibly solved! Time and miles will tell. Maybe I should call OBX and tell them. LOL. Look another person figured the same thing out here: http://forums.clubrsx.com/showthread.php?t=520556 Link to comment Share on other sites More sharing options...
75&78Z Posted January 28, 2009 Share Posted January 28, 2009 I’ve been following this thread with great interest as I received my OBX (from Tuna Tom) late October. Upon disassembly I noted all the previously mentioned issues, Poor quality washers, burrs, dirt, etc. The bolts however were grade 12.9. Also mine arrived with the gears properly arranged, so if you do plan on using an OBX don’t just flip the gears assuming they are wrong. I’m guessing it comes down to lack of attention to detail during assembly at the OBX factory. This next part is in regards to the machining tolerances of the OBX. My plan was to reuse the original ring and pinion in my R200. To help ease the set up of the ring to pinion, prior to pulling the open diff I checked the ring and pinion lash. It was between .006”and .0065”, (near the middle of the factory spec). After pulling the open diff and removing the ring gear I measured from the ring gear mounting surface on the diff to the two faces on the diff where the carrier bearing races seat. I then measured the same areas on the OBX and compared the numbers. The left (drivers side) was within .0005” (half a thousandth) however the passenger side dimension of the OBX was .012” smaller than the original open diff. Rather than try and order a new spacer ring from Nissan I cut an additional spacer from .012” steel shim stock and installed it along with the two original right side spacers. After reassembly the ring to pinion lash was now between .0055” and .006”. This may not be the best way to do it but it worked for me. Also I’m not sure if Nissan offers a spacer as large as I needed as the FSM showed spacer sizes ranging to a maximum of .007” larger than the spacer in my diff. I hope this helps. Link to comment Share on other sites More sharing options...
JMortensen Posted January 28, 2009 Share Posted January 28, 2009 Shims are shims and you don't need to use Nissan shims to get the diff set correctly. Cutting your own works fine. I would think that someone needing shims might go to a gear shop and find something close. MikeC has suggested that a 12 bolt chevy diff has shims that are pretty close in size, so that might be a first place to look, but most shops will have a big pegboard wall with different size and thickness shims, so it shouldn't be too hard to find something that works. Link to comment Share on other sites More sharing options...
cygnusx1 Posted January 29, 2009 Share Posted January 29, 2009 I notified OBX about this issue through their website and linked them to this thread. Link to comment Share on other sites More sharing options...
junglist Posted January 29, 2009 Share Posted January 29, 2009 This thread is great info. I'm going to probably have to order an OBX now. Link to comment Share on other sites More sharing options...
Daeron Posted January 30, 2009 Share Posted January 30, 2009 Chalk up another one for China!! (as long as we go back and make sure the QC is up to snuff, LOL) Link to comment Share on other sites More sharing options...
z-ya Posted January 30, 2009 Share Posted January 30, 2009 I did not rearrange the gears in mine. All I did was change the washers. I don't remember the exact configuration. Mine had the same 12.9 grade bolts, and was also quite dirty right out of the plastic bag and box. I did my best to clean it when I installed the new washers. I changed the gear oil once in it so far, and it came out looking nasty (dark). I will be taking it apart soon as I have a leaky pinion seal. I didn't replace the pinion seal when I put the LSD in (it was a junkyard R200). I'll post my findings. In operation the limited slip action is quite good. I would say that it slips less than a Nissan CLSD, but not much. You can easily predict it's behavior during wheel spin. As far as noise, it make a fair amount of gear noise but no clunking. Using a solid or urethane differential mounts will amplify this I'm sure. I have a Ron Tyler/urethane mount in this car. Maybe different gear oil weights can quiet it down more. Pete Link to comment Share on other sites More sharing options...
JMortensen Posted January 30, 2009 Share Posted January 30, 2009 In the one of the torsen pages I linked to there is a bit about using LSD additive for noise reduction. Link to comment Share on other sites More sharing options...
cygnusx1 Posted January 30, 2009 Share Posted January 30, 2009 It looks like my OBX unit is going to be a drop-in with the factory shims that came out. I need to double check but so far I get about 0.005"-0.007" backlash on the ring gear. I also set the belville washers with about 10ft/lbs of initial break-away torque (preload). I just didn't feel comfortable setting zero preload for fear of gear rattles, or too much preload for fear of excessive wear, so I took a conservative approach. We will see how it works hopefully in a month or so. Snow melts. Link to comment Share on other sites More sharing options...
JMortensen Posted January 30, 2009 Share Posted January 30, 2009 It looks like my OBX unit is going to be a drop-in with the factory shims that came out. I need to double check but so far I get about 0.005"-0.007" backlash on the ring gear. I also set the belville washers with about 10ft/lbs of initial break-away torque (preload). I just didn't feel comfortable setting zero preload for fear of gear rattles, or too much preload for fear of excessive wear, so I took a conservative approach. We will see how it works hopefully in a month or so. Snow melts. Did you check for slop as reported by 75&78Z? You don't want that slop in there, in fact you want the carrier to be hard to get into the housing because it's such a tight fit. Ideally it would be "have to smack it with a dead blow to get it in tight". Link to comment Share on other sites More sharing options...
z-ya Posted January 30, 2009 Share Posted January 30, 2009 With mine we had to order the correct shims from Nissan. They are cheap BTW. Without the correct shims there was too much slop, and the ring gear bolt heads just barely rubbed the pumpkin. Make sure the carrier rotates freely through a full rotation. With the stock shims mine rubbed on two of the ring gear bolt heads. Pete Link to comment Share on other sites More sharing options...
Zeero Posted January 30, 2009 Share Posted January 30, 2009 This is great news! I hope they hold up! I just purchased a new unit off of CL for $350. Once I get it installed I'll give my input about it as well. Link to comment Share on other sites More sharing options...
cygnusx1 Posted January 31, 2009 Share Posted January 31, 2009 I got unlucky in that the internal OBX gears were backwards but I got lucky in that the OBX measured within 0.001 to all the width and ring gear location to the original open center. Yes the OBX needed to be coaxed into place with a mallet. There are no bolt head interferences....yet! BTW here is the McMaster Part for 12mm to 10mm bushings for the ring gear bolt adaptors. 10 needed. 6679K14 http://www.mcmaster.com/nav/enter.asp?partnum=6679K14 On another note. I had my dad apply torque to the input shaft of the diff while I tried to turn the side shafts in opposite directions. It works. I could not break the breakaway torque with two long screwdrives wedged in the stub axle studs, when my dad applied input torque. Pretty cool. Link to comment Share on other sites More sharing options...
z-ya Posted January 31, 2009 Share Posted January 31, 2009 Cool. While I got mine apart I'll put in a set of those bushings. Pete Link to comment Share on other sites More sharing options...
z-ya Posted February 10, 2009 Share Posted February 10, 2009 I took my OBX apart tonight, and confirmed that the gears are arranged like this photo of a Quaife unit: Not the way cygnusx1 unit came: Please confirm that I am correct on this. The washers are in perfect shape. Little to no wear after one season of street driving, and a couple track days. I have my washers arranged like this: ))))((((. There is at least one washer of preload in this configuration. Pete Link to comment Share on other sites More sharing options...
cygnusx1 Posted February 10, 2009 Share Posted February 10, 2009 Pete great to hear. You are correct with your photos. The lower photo is how mine arrived wrong! How do the rest of the internals look as far as wear? Link to comment Share on other sites More sharing options...
NZeder Posted February 10, 2009 Share Posted February 10, 2009 Pete great to hear. You are correct with your photos. The lower photo is how mine arrived wrong! How do the rest of the internals look as far as wear? wow when I spotted the pics from Pete about his OBX and your talk about how yours was assembled incorrectly - it had me thinking if my unit was wrong too. Now given I was one of the first - if not the first to get one of these on Hybridz and give it ago - however my car is still off the road and all I have done is assemble the unit into the diff and paint it ready for the body to get back from the body shop...... Anyway I went back to the old threads see here http://forums.hybridz.org/showthread.php?t=107997&highlight=obx Back in 2006 - time just flys Anyway I found my pic of the unit I got and how it was assembled. You can see the difference vs the one from Pete. Link to comment Share on other sites More sharing options...
z-ya Posted February 10, 2009 Share Posted February 10, 2009 Dave, no sign of wear that I could see. Yup, mine was assembled like this out of the box: Link to comment Share on other sites More sharing options...
cygnusx1 Posted February 10, 2009 Share Posted February 10, 2009 I just want this to be clear !!!!WRONG!!!! Link to comment Share on other sites More sharing options...
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