DIFF HELP! I HAVE A PROBLEM

[yellowcell]

Okay heres the deal, I bought a JDM diff from a guy off of this forums, well i slapped it on and it was ALL TIME complete locking(making simple turns which are 90 degrees it locks). So i went ahead and thought it was a welded. Well now i just took the diff off and guess what? it has a Viscous in it... here is a picture. I tired turning the side pumpkins and it does not give. it is complete locking. It is loose about 1 mm. please help.

Is it a 2 way? or is it broken?

[kansaschity]

why didnt you drain it before you pulled it

[yellowcell]

why? i dont see wwhat that has to do with figuring out if it is a 2 way or not

[Neil]

I dont know what a viscous (most jdm S13's had a viscous, the same unit as in hicas US cars) diff-pack looks like but that sure looks a lot like my ATS clutch type lsd. I'm willing to bet it's either a japanese clutch LSD (hence 'JDM') or the dude you bought it from assumed it was a viscous taken out of a 180 or Silvia.

also as far as I know its not possible to tell visually weather its a 1 way, 1.5 way or 2 way. The way to tell is by driving it and see if it grabs as hard while turning + engine braking. If it grabs as hard, its a 2 way. If its significantly less hard, its probably a 1.5. If it's a 1 way, it won't grab at all while turning on trailing throttle.

A mechanical LSD will 'peg leg' (wind up, release... wind up, release..) slightly while making gentle turns under throttle. They'll grab and clunk and pop a lot during tight manuvering in a parking lot. If it's mechanical You will have a VERY hard time turning the output shafts in opposing directions by hand. That's why there's something called "breakaway torque", how much torque is needed before the output shafts can be rotated in opposing directions. That can be set somehow with the hole in the side of the clutch-pack basket as seen in your pic but im not about to suggest messing with that.

I dont know what you mean by 90° turns and "Simple"... the wheels are rotating very different speeds when making a turn like that, even if its a 90° turn that's drawn out 300 feet.

My Deftforce would grab like a ***** just driving normally, it was so sensitive it would lock up if I made so much as a lane change. After putting 2000 miles on it it's gotten a lot better daily driving (my 21mm rear sway bar helped control the understeer from it locking too tho), but as to be expected it still grinds/clunks/acts ****ty in tight spots and still locks exactly when i want it to.

also, where is the 1mm of play? does the input flange rotate 1mm before the outputs turn, or do the outputs turn 1mm away from each other before you can't turn them anymore? either way is perfectly healthy. My input flange turns about 5 or 6mm before the output shafts turn and it's been fine. When im on trailing throttle it sounds like a schoolbus transmission but it's always done that, even with the open diff. I could shim out the pinion gear but i'll only do that if it starts acting ****ty.

hope that helps a little. p.s. change that fluid! if it is what i think it is, get some kaaz 80-90w from 240sxmotoring.com. yr also gonna need a new gasket, i wouldn't reccomend using gobs of RTV to 'fix' this one... RTV usually has a high sulfur content and I dont know what'd happen if it contaminated the oil. get a new gasket from autozone and use a very thin bead of rtv and let it dry a few hours before putting more oil in it.

this post has been editited about a dozen times.
Modified by Neil at 9:48 PM 6/3/2006

[Ca_laurier]

you have an aftermarket lsd in there. here is a picture of a stock lsd: