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Symptoms Of A Broken Diff?

Manuel Kasko
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GTSBoy Grand Master

GTSBoy

Posted
Posted (edited)

Depends which gears i guess.

The old holden v8 diffs must have big gears and room to do it, cos it worked well for ages,

its not suprising cos they are simple and big.

I know squat about LSDs, and he didnt tell me jack yet so.... monday, Dan i guess ill find out what he can do.

What are you talking about GTSBoy, shimming the gears or the clutches?

I like to know which ideas are crap so i dont get burned.

Anyway its definately rooted, sounds worse after an oil change.

I was specifically talking about "shimming" the viscous coupling in the standard VLSD. There are no clutches in a standard VLSD. There is only the viscous coupling. When people talk about "shimming" a VLSD, they are talking about putting in one or more extra of the spacer shims that are just put in there normally to adjust the slop out of the assembly. By jamming another in there they take out all the slop and load the outside of the viscous coupling against the inside of the centre, which has the effect of making it seem like they have tightened up the LSD part of the diff (which they have) but in a totally bodgy way that leads directly to wear and f**kedness.

You can of course (and indeed must) correctly set up the pinion to crownwheel by using the correct thickness crush spacer (or a carefully machined to correct thickness solid replacement for a crush spacer) when you set a diff up from scratch. This would normally be expected to take out all the slop and backlash in the CW&P....that's what it is intended to do. However........I had a good diff guy build my current diff from a number of bits. My original R32 housing, an S15 helical centre and the 4.11CW&P from an R34 VLSD. He set the CW&P spacer up beautifully. Nice solid machined spacer. Mesh is perfect. My diff/driveline makes the same sort of clunking noises you are all complaining about above. My tailshaft doesn't have a lot of slop, and my driveshafts do not have a lot of slop either. I can only assume that the helical centre I have has a lot of loose slop in the mess of gears in the middle, and that is where my noise hides. If I hadn't spent so much money putting what I have together (including swapping to 3x2 bolt driveshafts to match the S15 stub axles), I'd go out and get another one. So, I just live with it. I don't care. I just drive with it in mind and make my shifts and clutch actions appropriately if I don't want to hear it.

Edited by GTSBoy
WMDC35 Experienced

WMDC35

Posted
Posted (edited)

Hey guys,

Shimming tightens the LSD up and is nothing to do with the backlash, the diffs would need to be adjusted to take up the slack, if you dont know what you are doing just take the centre to a diff guru :)

If i was in Canberra i would help but 4hrs is a bit far for a quick look!

He is referring to a mechanical diff centre i would say, a lot of fun but they do clunk and carry on in carparks as they are basically locked anyway....

You should be able to check the diff bushes, subframe, tailshaft, gearbox and engine mounts etc man...... Its hard to picture what is happening from your description though......

this, the shim will only tighten the lsd action in the cheapest way, apart from welding it haha, the metallic ting sort of noise when put in reverse will be backlash which is just from wear, I'd prob just put up with it until diff upgrade time

Edited by WMDC35

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