Hemi Posted September 16, 2009 Share Posted September 16, 2009 right thought id give a bit of a writeup on r200 shortnose and longnoses . feel free to add any info that you KNOW is true so we can have a place to get good info from etc . right here is a shortnose r200 out of a..dunno but its 4:11 ratio and has a viscous center in it the longnose r200 is a 3.9:1 ratio out of ..fuck knows r30-31 skyline, datsun 280z or maybe a c31 laurel right when the rear covers are taken off here is what is inside , the shortnose is on the left , note that the housing looks alot bigger , it probably is but they are the same diameter. here we have both covers side by side , note that the shortnose has different spaced rear mount studs shortnose is 125mm center to center whereas the longnose is 85mm center to center next we have both carriers with crownwheels on side by side both are the same height 166mm end bearing to bearing if you look closly you will also see that the crownwheels are of different thickness shortnose:27.6mm longnose:29.7mm heres a top view of the carrier you can see that the shortnose crownwheel is wider then the longnose item 32.6 vs 29.7 mm heres the two carriers side by side the lsd unit is slightly higher then the open one , this concerned me because a higher platform + thick crownwheel = waaay outta whack ..however when the longnose crownwheel was put on the lsd unit its came up at 85mm ..perfect after this i decicded to pull apart the carrier to show ppl what inside etc . this is the viscous unit itself the large gear mates up to two smaller spiders gear and by using the shear strength of a silicone liquid (similar to what you find in fans) provides a lsd type action while not as positive as a clutchpack will outlast a clutchpack lsd by far . this is the underside of the viscous unit , not much interesting here but you can see two holes ont he backside , this is for draining and filling the unit ... the unit is fully sealed so there is no need to run an lsd type oil in this diff ...it will not make 5 5ths of fuckall of a difference . right here one side of the carrier case i took this picture to show you the shim that is here ... now some people belive that you can 'shim up' a viscouse lsd by adding washers here ...WRONG ...this shim sets the spidergear - viscous unit gap ... by adding washer here all you are doing it pushing the viscous unit out loading up the spider gears the lsd action of a viscous unit is decided by the viscosity of the silicone fluid not these shims . last but not least just a pic to show you the difference between a 2 and 4 pinion diff .first is the 2 pinion . these are alright but have a terrible habit of breaking the roll pin the holds the pinion rod in . once broken the rod makes its way loose tearing the carrier apart and taking everything with it . this is a 4pinion setup ..note how all spider gears are held by one hub ... these are far stronger and fail far less compared to the 2 pinion type .You will also notce the lsd spiders are alot smaller ... but there is one more of them in theory and the lsd action of the unit helps take the stress off them by lowering difference in shaft speeds . hope this helps some people . Right now heres what ive found : the cover bolts are different . shortnose = 12mm long = 10mm the crownwheel to carrier bolts are different shortnose=13mm longnose=10mm this means you need 3mm bushes to go into the shortnose carrier to mount it into a longnose housing . this is as far as i got tonight seeing as i dont have my own personal engineer on hand . random specs: shortnose longnose cover mount bolt spacing 125mm 85mm crownwheel thickness 27.6mm 35mm crownwheel width 32.4mm 29.7mm carrier hieght 166mm 166mm crownwheel bolts 13mm 10mm (both shortnose and longnose crownwheel bolts are the same length) Quote Link to comment Share on other sites More sharing options...
kyteler Posted September 16, 2009 Share Posted September 16, 2009 C31 Turbo Laurel. I told you that, you numpty. Sweet write up though man, keen to keep an eye on this for my other R200 in my spare 110 rear-subframe. Quote Link to comment Share on other sites More sharing options...
RUNAMUCK Posted September 17, 2009 Share Posted September 17, 2009 I make the adapter bushes to put the longnose crownwheeel, onto the later viscous center. The viscous centers used both 12, and 13mm crownwheel bolts. If anyone needs a set of bushes, Pm me. Quote Link to comment Share on other sites More sharing options...
Hemi Posted September 17, 2009 Author Share Posted September 17, 2009 i dropped my crownwheel and carrier off to my mate to make some .. mainly cos he is closer . Quote Link to comment Share on other sites More sharing options...
RUNAMUCK Posted September 18, 2009 Share Posted September 18, 2009 fair enough. I ussually set a set of 11 (One spare cos they are very easy to lose) for $30. They are piss easy to make, but bloody time consuming. Quote Link to comment Share on other sites More sharing options...
zips1 Posted April 11, 2012 Share Posted April 11, 2012 so all ill need to make this conversion work is the spacers ? dont need to modify half shafts ? seems to simple !! Quote Link to comment Share on other sites More sharing options...
RUNAMUCK Posted April 11, 2012 Share Posted April 11, 2012 What car do you have Zips? The other thing which has been ommitted from this sweet sweet how-to, is that one of the input shafts needs to have the longer input, which includes the smaller splined section at the end to engage into the viscous cartridge. If you already have CV halfshafts, then no problem. If you're still rocking dirty old UJ's, then it's a bit more fucking around. Quote Link to comment Share on other sites More sharing options...
86trueno Posted April 12, 2012 Share Posted April 12, 2012 anybody have the part number for the boots for the CV shafts? just done this conversion for my 1600 and have shortened cv axels but the boots are abit old so im looking at replacing them Quote Link to comment Share on other sites More sharing options...
DJZ Posted April 12, 2012 Share Posted April 12, 2012 Take the joint + shaft down to Repco or where ever and match one up. Quote Link to comment Share on other sites More sharing options...
Hemi Posted April 12, 2012 Author Share Posted April 12, 2012 What car do you have Zips?The other thing which has been ommitted from this sweet sweet how-to, is that one of the input shafts needs to have the longer input, which includes the smaller splined section at the end to engage into the viscous cartridge. If you already have CV halfshafts, then no problem. If you're still rocking dirty old UJ's, then it's a bit more fucking around. wait wut??. naw man the output shafts on this are the same length and size do0d. the r180 lsd does however have those different output shafts well thats my experiance anyhow Quote Link to comment Share on other sites More sharing options...
RUNAMUCK Posted April 12, 2012 Share Posted April 12, 2012 I'm talking bout the bit on the end with the smaller spline. ONe input goes all the way through the center into the viscous cartidge. If he has CV shafts, then it's no hass to butcher the inner one apart, and swap it for the two peice later model (R32 etc) and fit the 3x2 (etc) inner input flanges. Without the extra spline, the diff will just be open. In a car that rocks UJ's the viscous caridge drive part needs to be welded, or otherwise attached to the input. Quote Link to comment Share on other sites More sharing options...
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