Forums/Z31P/z31-performance-upgrade-forums driveline-aa/Diff. Ring Gear Tightening Torque
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frostvectron: (2013-01-13 02:24:11)
I am flipping through the FSM (1986) in the propeller shaft & differential carrier (Page PD-31).
It has two different torque values for the nonturbo and turbo cars for the ring gear bolts.
Nonturbo (VG30E) : 51-58 Ft-lbs
Turbo (VG30ET) : 98-112 Ft-lbs
I was under the impression that the ring gear and bolts were all interchangeable for long-nose R200s. With the same components, why are the torque values so different? It makes sense that the turbo (higher HP) cars need to be tighter, but if the bolts can take 98-112 Ft-lbs, why not just have all the R200s tighten to that spec?
Careless: (2013-01-13 17:56:09)
at the time of printing, perhaps the non turbo used 10mm bolts and the turbo used 12mm bolts.
frostvectron: (2013-01-13 22:04:26)
Does that mean that they actually use the same bolts now? *first time taking apart R200*
Which torque spec should I use?
Gregmatic: (2013-01-15 03:44:39)
I personally would use the higher of the two. AS Careless said, 84/85's had 10mm ring gear bolts which may have limited their toque values.
NissanEgg: (2013-01-15 05:07:16)
If it is a 10mm bolt, use the lower of the 2.
If it is a 12mm bolt, use the higher of the 2.
Using the higer spec on the 10mm bolt is just asking to break the bolt, or strip the threads. That would be disaster in a high torque load like a diff.
frostvectron: (2013-01-15 06:15:37)
Got it. Thanks!
One last thing since I've got the experts' attention. The FSM says to use a threadlocking compound for the ring gear bolts and the mating surface between the ring gear and the diff. Any ideas which strength threadlocker to use? I was guessing the locktite blue (medium strength).
Augustus Maximus: (2013-01-17 08:50:18)
[archived image: VLSD1.jpg]
80lbs with red loctite when I did the VLSD swap.
vegasZ31T: (2013-01-18 03:19:20)
You might try the differential service manual
http://www.xenonz31.com/files/Z31%20R20 … ted%20Slip).pdf
frostvectron: (2013-01-18 03:31:47)
That is the same document that I am asking a question about. We are referencing the same thing.
G-E: (2013-01-18 17:18:10)
http://www.cncexpo.com/MetricBoltTorque.aspx
Metric has specified torque ranges for all bolt sizes, the above posts are correct stating the M10's should have the lower figure.. the confusion is not all years/models seem to have consistent ring gear/bolt types
vegasZ31T: (2013-01-18 18:19:53)
Sorry, you said the 86 FSM. This is a bit different.
Anyhow best of luck.
frostvectron: (2013-01-18 19:09:32)
Ah, you are correct. These two are NOT the same document but very similar. They are the same until page 30.
The document you posted has one additional section for the Limited slip Differential. I am guessing that the page you posted is taken from the propeller shaft and differential carrier section of a 87-89 FSM since it covers the LSD part too.
However, both documents show the two differing torque values (PD31 in the 86FSM and PD39 in the document you posted).
I will measure the bolts and go from there. Thanks everyone!
vegasZ31T: (2013-01-18 21:23:43)
You might also check out the other material on the "Reference" page on http://www.xenonz31.com.
frostvectron: (2013-01-24 23:45:32)
Alright guys,
I have a new problem but it is related so I will post it up here.
The ring gear bolts are completely stuck from a used LSD I bought. It's from a 240sx, so I have to remove the ring gear so I can use my own ring gear.
I tried both a huge breaker bar and an impact gun. Didn't budge… any ideas?? I am currently dripping acetone on the bolts in an effort to dissolve any loctite there (and hoping that's the reason why they aren't coming off).
85NA2T: (2013-01-25 14:31:45)
Try some heat? And just to make sure,you do know they are RIGHT hand thread,correct?
NissanEgg: (2013-01-25 15:35:45)
As in lefty tighty, righty loosey?
frostvectron: (2013-01-25 16:12:40)
They are left hand threaded (clockwise to loosen)?? That is news to me… the FSM for the 240sx didn't mention that at all. [archived image: confused.png]
The ring gear from the z31 is typical right hand threaded (counter-clockwise to loosen).
DeleriousZ: (2013-01-25 16:57:11)
I had a bitch of a time getting the ring gear bolts out on my LSD (88 clutch type) when I was rebuilding it. I busted 3 sockets because my impact sockets wouldn't fit. Eventually they came out with tons of heat and lots of impacting!
frostvectron: (2013-01-25 16:58:03)
How much heat is safe to use on the diff? Propane torch?
The z31 ring gear came out fine… the 240sx one is crazy stuck (damn 240sx guys).
85NA2T: (2013-01-25 17:10:28)
Sorry i ment RIGHT hand thread as in left loosey righty tighty.Just making sure because some domestic stuff (yes i know this isnt a domestic) use left hand thread ring gear bolts.Edited prior post
Careless: (2013-01-25 17:58:05)
i couldnt even mount the diff carrier into anything stable enough to break the fastening hold, so that's why I never opened the fucking thing. they're on there pretty good. thaaaaaaaaaanks nissan.
DeleriousZ: (2013-01-25 18:08:44)
I ended up doing a one armed bear hug over the differential as it sat on a wooden shelf, and hitting the bolts with an impact gun in the other hand lol.
frostvectron: (2013-01-25 18:46:53)
85NA2T, Thanks for clarifying!
Yes, holding the stupid thing is hard because the case is round. I am clamping it into a huge bench vice with a lot of force but even then it doesn't feel super stable. Holding the open diff was way easier because the rectangular shape.
DZ, I tried an impact gun on it while it was clamped in a vice and held by a friend for extra measures.... didn't budge. Crapppppp.
frostvectron: (2013-01-26 02:45:57)
Got it! Gentle use of a propane torch and a 5 ft. long bar for leverage!!
Some nasty smelling chemical poo in the threads.
Careless: (2013-01-26 04:27:46)
i wouldn't attempt that myself for fear of spinning a large ring gear too close to my body while hugging it like a carrier bearing. lol you brave breaux. id rather go fight a black bear.