Hi Guys,

I have a 2003 JDM Sti and the rear diff has a lot of (as I would describe it) pinion slap. When on and off the throttle at low speeds it clunks quite bad.

It has been like this for a couple of years now and not got any worse, but it is at the stage where I just want to take it apart and reset the backlash so that it feels better.

When doing this I was wondering if upgrading the LSD was a good upgrade? What do people recommend? Tighten the plates or change out for aftermarket?

The car is only used a small amount every year for some spirited summer weekend driving and as it is I like how when accelerating out of a bend the car squats and you can feel the rear slightly step out, then it straightens itself, all very nicely and controllably. So as is I am happy with how the rear end behaves.

When resetting the backlash also where is the best place to provide the correct parts for a JDM? I'll need seals and shims, maybe change the bearings while in there?

Anybody who has any advise it would be greatly appreciated (or done it before with a few tips, welcomed).

Thanks for your help.
Chew

 

Here's some info https://forums.nasioc.com/forums/sho....php?t=2726130

Depending on how worn your clutch and spring plates are you might need to get the full clutch rebuild kit, easy to find in Japan but I guess someone in UK sells it too. But you should measure the preload of the LSD to see if it really needs a rebuild. The R180 I got with my 6-speed was very worn out though and basically had no preload at all.

I haven't touched the backlash, changed the size of the side shims, as that's something I don't feel comfortable doing.

 

Thanks mate, appreciate that.

I am happy enough to check the backlash and change the shims as required, I have never done a car one but have done numerous tractor ones and they look to be almost exactly the same (except size, obv).

When the car is lifted and the rear wheels held with the handbrake there is a lot of movement in the pinion/driveshaft so I'm sure its what is needed.

I'll check the preload on the LSD and see if it needs doing while in there.

 

You are sure that you have plated rear diff?Because jdm sti 2003 has suretrac,spec c has plated.I have suretrac on my edm sti 2004 and when accelerate on a bend my car behaves the same as yours.The clunk you hear is probably from worn diff bushings and outrigger bushings.If you have dccd transmission you have plated rear,if you have viscous center diff you have suretrac.

 

It’s hard find accurate information but I’m fairly sure I have a r180 with plated lsd in the 2003 jdm sti - 6mt dccd - same as the spec c - the Suretracs are in the non dccd models.

i have looked at the diff and out rigger bushes and they are good.

Its not the lsd part I think the problem is in though as I can feel the play on the driveshaft with the rear wheels locked. Just wondered if there is a good upgrade while I’m in there.

 

Beatrush has a rear diff brace,and sti too with product code ST413104S020.This,with diff outrigger insert bushings may cure your problem