Dr Jeckyll

[zukitek]

I know this is from Zilvia (def not the most amazing place for intellectual knowledge), but there's several people I know of in person that have done this.

http://zilvia.net/f/s-chassis/200226-shimming-r200-j30-vlsd.html

These are apparently the different sized shims you can get from Nissan (allegedly each costs about $6.00):
38424-40F60 =0.80mm
38424-40F67 =1.01mm
38424-40F75 =1.25mm
38424-40F83 =1.49mm

Even drift guys say the 0.80mm is plenty, as it locks very hard. So there's something to look into. For the cost of a tube of RTV, and a $6.00 shim, you could have a nice LSD.

Well it depends on whether they are doing this to an open diff or a viscous . I have a whole drawer full of diff specific shims in differant thicknesses from past diff and ring and pinion I have built. The VLSD housing splits in 2 halves and the viscous unit sits inside and has a gear that engages all 4 of the spider gears. The viscous unit itself is not readily disassembleable but I can tighten the clearance shim that adjusts the load of the viscous gear against the spiders and if I do it tight enough it will actually bind the spiders up which should make it behave as a welded diff in a straight line but allow the wheels to turn independantly when turning . It could either work or it could build up heat excessively and cause it to gall but I have a couple of them laying in the garage so its not like im losing anything. Ill see how it goes .

[nicktcr]

Well it depends on whether they are doing this to an open diff or a viscous . I have a whole drawer full of diff specific shims in differant thicknesses from past diff and ring and pinion I have built. The VLSD housing splits in 2 halves and the viscous unit sits inside and has a gear that engages all 4 of the spider gears. The viscous unit itself is not readily disassembleable but I can tighten the clearance shim that adjusts the load of the viscous gear against the spiders and if I do it tight enough it will actually bind the spiders up which should make it behave as a welded diff in a straight line but allow the wheels to turn independantly when turning . It could either work or it could build up heat excessively and cause it to gall but I have a couple of them laying in the garage so its not like im losing anything. Ill see how it goes .

I only briefly skimmed through that tutorial, but I thought I saw them actually disassembling the VLSD unit and swapping shims. I've never actually disassembled the inside of a diff. Only pulled the guts out and melted them to do unspeakable car things later.

I only passed it along as I stumbled upon it and remembered you mentioning needing a quick fix.

[zukitek]

I read the thread and that is exactly what they are doing . They are shimming it tight enough to bind the spiders . I may give it a try but probably wont . It would be more effective to weld it and wouldnt have the potential to damage the thing . Still leaning towards the helical the heaviest though.

[TouringBubble]

Preloading the spiders is exactly what I've seen done for the VW trans as well.