Adding preload - plated R180
 

Hi perth-wrx,

I have an 02STI with an upgraded MY06STI plated R180 rear diff and recently added Cusco Tarmac Gear centre diff.
My rear diff seems to lock both wheels under hard acceleration but I'd like the lock to occur a little sooner (higher breakaway torque).
We have a steep driveway which kicks the inside rear wheel in the air and unless we get a runup, the inside wheel will infinitely spin!:confused:
I had the diff apart not even 6 months ago & the friction discs & plates are within spec'.
Anyone know how I could shim the diff enough to give me a little more preload without it becoming like a welded diff?

Cheers.

Daz. Ex Dianella westie (I escaped to Melbourne!:icon_butt)

yeah, you can add shims to a Plated diff. Not too sure how thick you'd wanna go though.

You can also flip the cone plate around.

R160 Plated Diffs come with 4 cone plates (2 per side) total where as R180s only have 2 (1 per side). But the R180s run larger diameter friction plates so it balances out.
So if you wanted to you could remove the outer friction plates and replace them with cone plates.

Thanks for the response, mate.
Considering the R180 was designed for 3 plates & 2 discs each side, would removing a friction plate not compromise the clamping force of the diff'?
I know the Skyrine guys (R200's) add what looks to be a simple washer at the end of each diff case but unsure if I can do this or if I need to laser cut a friction plate looking shim?

Anyone done any R&D with this?

tried thicker oil?

I use what I beleive is the best available fluid on the market?
[url]http://www.tds.castrol.com.au/pdf%5C3872_safxa_b1769_04.pdf[/url]

This could work?!

[url]http://cgi.ebay.com.au/PEGLEG-LSD-warning-sticker-for-VK-VN-EB-ED-EA-Pintara_W0QQitemZ180443765455QQcmdZViewItemQQptZAU_Car_Parts_Accessories?hash=item2a03495acf[/url]

I use Redline Heavyweight shock proof myself in my Plated R180. Even with the DCCD open I have no issue climbing up a steep kerb.

What model DCCD gearbox?
The pre MY06 with the totally open centre?

yeah. Its a my05 DCCD box with the 35:65 DCCD center. Same open torque split as your Cusco Tarmac.

My car does (did) this exact same thing with a plated R180 and DCCD fully open. I could get it to move by applying some lock to the centre diff.

I was under the impression that this is a trait of mechanical LSD's that use torque sensing as opposed to speed, lift a wheel and it will just spin?