brianZortiz Posted May 22, 2011 Share Posted May 22, 2011 I got a call from Hoopers Rear End exchange in Sun Valley, CA about my differential, stating that the pinion gear welded its self to the bearing. Its a CLSD from the z31 and he said that it would be better if I find another differential to swap over the CLSD unit. Alexander said he can swap over to any r200 for $150, not bad in my opinion. I can get my hands on a 3.9 Open from a 280zx 5 speed 81-83 for $75 bucks. The main Question is: will the differential be as strong as the original 3.7 LSD if put on the 3.9 open? This setup will be ideal for my close ratio 83 tranny. If converted to 3.9 CLSD will it be the same thing as a JDM R31 3.9 LSD? Thanks -Brian Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted May 22, 2011 Share Posted May 22, 2011 The main Question is: will the differential be as strong as the original 3.7 LSD if put on the 3.9 open? Thanks -Brian Yes. Quote Link to comment Share on other sites More sharing options...
brianZortiz Posted May 22, 2011 Author Share Posted May 22, 2011 Thank you, sir! Quote Link to comment Share on other sites More sharing options...
Mack Posted June 3, 2011 Share Posted June 3, 2011 I think the bolts holding the clsd unit to the ring gear are bigger on the z31 unit. so, if you bolt it to the 280zx unit you will have to get a slweeve to go around the bolt to make up for the smaller diameter of the 280zx ring gear bolts. a bolt in option for a a 3.9 R200 is to get one out of an infiniti M30. It uses the same bigger diameter bolts as the later 300zx rear diffs with the clsd. This is the setup I am running in my 280zx and IIRCthe only modification I had to do was a bit of grinding on a casting on the underside of the M30 diff. took me 5 mins aith an angle grinder and it was a bolt in after that. Quote Link to comment Share on other sites More sharing options...
brianZortiz Posted June 3, 2011 Author Share Posted June 3, 2011 Thanks Mack, I will give the Differential Shop a call to see if they have a way through this. I already acquired the 280zx 3.9. I didn't know about the infinity m30 but it's always great to learn about different swap possibilities and alternatives. Quote Link to comment Share on other sites More sharing options...
nismo_zxt Posted June 3, 2011 Share Posted June 3, 2011 (edited) The r200 from the 280zx use the 10mm bolt to retain the gear ring. Same as the Z31 '84 - '85. The z31 '86 to '89 all use 12mm bolt for any ratio 3.545/3.7/3.9 They all use the same case. Like Mack said you will need sleeve If you took the pinion and gear from the 280zx and take the CLSD from the z31, Your bolt/ring will be 10mm thru 12mm CLSD hole. You will need sleeve the CLSD for 10mm bolt. About the R31 JDM 3.9 you may have better choice to be the same. Model Year's Bolt Ratio z31 86 NA 12mm 3.7 Open z31 86 T 12mm 3.545 Open z31 87 NA 12mm 3.7 Open z31 87 T 12mm 3.545 Open & 3.7 CLSD z31 88 NA 12mm 3.9 Open z31 88 T 12mm 3.7 CLSD z31 88 SS 12mm 3.7 VLSD z31 89 NA 12mm 3.9 Open z31 89 T 12mm 3.7 CLSD Edited June 3, 2011 by nismo_zxt Quote Link to comment Share on other sites More sharing options...
brianZortiz Posted June 13, 2011 Author Share Posted June 13, 2011 Wow. Thanks nismo_zxt. I will try to find a z31 differential in either 3.7 or 3.9. This upcoming weekend it's 50 percent off. This is very useful to source a specific year/ratio z31 diff. -brian Quote Link to comment Share on other sites More sharing options...
mario_82_ZXT Posted June 13, 2011 Share Posted June 13, 2011 You can buy the sleaves at McMaster-Carr, the part number is given in one of thte OBX diff threads. Quote Link to comment Share on other sites More sharing options...
nismo_zxt Posted June 14, 2011 Share Posted June 14, 2011 It's been a pleasure! I had to get her information for my project and if this can help someone else, is even better. BTW, here's the complete list of the 84 to 89 spec. Z31/300ZX Z31 '84 NA 10mm 3.7 Open R200 Z31 '84 T 10mm 3.545 Open R200 Z31 '85 NA 10mm 3.7 Open (Before 09/85) R200 Z31 '85 T 10mm 3.545 Open (Before 09/85) R200 Z31 '85 NA 12mm 3.7 Open (After 09/85) R200 Z31 '85 T 12mm 3.545 Open (After 09/85) R200 Z31 '86 NA 12mm 3.7 Open R200 Z31 '86 T 12mm 3.545 Open R200 Z31 '87 NA 12mm 3.7 Open R200 Z31 '87 T 12mm 3.545 Open & 3.7 CLSD R200 Z31 '88 NA 12mm 3.9 Open R200 Z31 '88 T 12mm 3.7 CLSD R200 Z31 '88 SS 12mm 3.7 VLSD R200 Z31 '89 NA 12mm 3.9 Open R200 Z31 '89 T 12mm 3.7 CLSD R200 Quote Link to comment Share on other sites More sharing options...
brianZortiz Posted June 17, 2011 Author Share Posted June 17, 2011 @Mario_82_ZXT. Thanks! @nismo_zxt I went to junkyard today and found a NA open r200. I opened cover and it sure was a 3.9. Now on to the Diff shop to put CLSD. Thanks again! Quote Link to comment Share on other sites More sharing options...
New 2 z Posted June 18, 2011 Share Posted June 18, 2011 (edited) the ring gear and pinion NEED to be bought in sets or you will grenade your diff. when they leave the factory their already broken in and meshed to each other. the open diff R200s are giant pieces of ****. i finally did mine in on the 1/4 mile when i was running a evo. the pinion that holds the spider gears in place broke in 2 places and my top spider gear got loose and found it's way in-between the case and the open diff and locked up my rear end and then my pass wheel diff gear decided to strip all its gears out while all of this happened. not one piece of it was salvageable, it was a total loss. i saw the same kind of fatigue on a customers diff, it didnt get near what mine did but it was on it's way. the spider pinion was cracked in half. the spider gears were already having issues turning. i have a VLSD and it looks so much stronger then the open diff. I'm only making 230 AT THE MOST! my customer was making 240hp (these are at the wheel figures.) the clutch lsd's for the Z31 are alright but it's a ***** finding a rebuild kit which is why i went VLSD. it ran me 150 at the most. remember when ever you assemble a diff to ALWAYS use diff paste and shim your diff properly for long live and proper drive-ability. use blue lock-tight on the ring gear bolts for extra security and peace of mind. also nismo ZXT you are wrong the 87 turbo DID NOT have 3.54 gears the ring gear bolts are NOT 10MM they are 12 from 84 - 85 and 14 on up Edited June 18, 2011 by New 2 z Quote Link to comment Share on other sites More sharing options...
NewZed Posted June 18, 2011 Share Posted June 18, 2011 Here's the page from the 1987 FSM, it says the 1987 Turbo cars had 3.54 gears. I've heard that there are some errors in the FSMs. Can you tell where you got your information from? Quote Link to comment Share on other sites More sharing options...
nismo_zxt Posted June 19, 2011 Share Posted June 19, 2011 (edited) I think you should dig little more before starting the confusion! I get my info from Nissan dealer. About the 3.545 gear, my info came for FSM manual and confirmed my the Dealer. Same has Newzed listed above. The part number for the 3.545 ring and pinion set installed in the '87 Z31 Turbo is the :38100-13s01 From where did you found the info about the bolt? The 10mm bolt (named) may be smaller or larger than 10 mm exactly but they are listed and named has 10mm nissan dealer number is 38120-N3100 And for the 12mm, same thing (named 12 mm). Nissan number is 38120-12s00 Search and you will see. All the Z31 R200 before production date, 1985.09, used the 10 mm bolt (38120-N3100) And this date, is the moment that they stop the production of the '85 Z31 to start the '86 production. AND 14mm !?!?! The bigger R200 ring bolt I saw 13mm and they are installed on the short r200 in the s14, s15, r32, r33, ... cars. So the parts number for the 13 mm (named) ring bolt are : 38102-rs500 Also some of the nismo, cusco, tomei LSD use those 13 mm. Like my CUSCO RS one. And if you ask... the hole in the LSD is 13.26mm for an bolt at 12.67mm EXACTLY. Also, give the sources that we can verify and confirm what your say or to confirm my mistake. I may be wrong, but as far as I remember, all the parts that I found via this list was accurate. Cheer Edited June 19, 2011 by nismo_zxt Quote Link to comment Share on other sites More sharing options...
New 2 z Posted June 19, 2011 Share Posted June 19, 2011 (edited) I think you should dig little more before starting the confusion! I get my info from Nissan dealer. About the 3.545 gear, my info came for FSM manual and confirmed my the Dealer. Same has Newzed listed above. The part number for the 3.545 ring and pinion set installed in the '87 Z31 Turbo is the :38100-13s01 From where did you found the info about the bolt? The 10mm bolt (named) may be smaller or larger than 10 mm exactly but they are listed and named has 10mm nissan dealer number is 38120-N3100 And for the 12mm, same thing (named 12 mm). Nissan number is 38120-12s00 Search and you will see. All the Z31 R200 before production date, 1985.09, was the 10 mm bolt (38120-N3100) And this date, is exactly the moment that they stop the production of the '85 Z31 to start the '86 production. AND 14mm !?!?! The bigger R200 ring bolt I saw 13mm and they are installed on the short r200 in the s14, s15, r32, r33, ... cars. So the parts number for the 13 mm (named) ring bolt are : 38102-rs500 Also some of the nismo, cusco, tomei LSD use those 13 mm. Like my CUSCO RS one. And if you ask... the hole in the LSD is 13.26mm for an bolt at 12.67mm EXACTLY. the j30 diff i used (same as Z32 etc) was a 14mm bolt it was from a 94 - 96 model. the ring gear bolt i took from my diff that blew up was 14mm as well and the bolt i have from my customers diff was 12mm I can get pictures along with socket sizes and measurements if you guys would like? also are you guys measuring by the head or by the thread size? additionally; http://az-zbum.com/information.differential.shtml http://www.xenonz31.com/reference.html Edited June 19, 2011 by New 2 z Quote Link to comment Share on other sites More sharing options...
nismo_zxt Posted June 19, 2011 Share Posted June 19, 2011 (edited) Always by the thread size. When is see a both at 1/2-13 the thread is around .500" in DIA. I know those site. I started my search with those. Nice for reference, but I dig little more and found the the '87 Turbo has different spec seen the 3.7 CLSD diff. arrive on the 04/87 (in USA) All the '87 turbo model made before this date has the 3.545 open. Both site said '87T CLSD has 3.7 gear. And they said they are availble in the 04/87. But what was in the '87 before the 04/87? So I found the FSM and ask the dealer to confirm this. Me and the dealer guy have found that the numbers for the '86 Turbo setup was installed in the 1st version of the '87, before the CLSD arrive. BTW, here in Canada, the '87 Turbo with 3.7 CLSD arrive in the '88 Turbo version. So the '87 has the 3.545 open diff all the year. I just mesuring the 13 mm bolt I got. The head flat-to-flat is 16.89mm And like you said I highly sugess to install the Ring and pinion has a commun sets. So if you talking about the 14mm ring bolt on the Z32 or J30 differential, they are the short R200 diff. And the pinion from the short one with not fit for sure in the longnose R200. Edited June 19, 2011 by nismo_zxt Quote Link to comment Share on other sites More sharing options...
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