LSD clutch plates

[alync205]

I took apart my LSD yesterday to see how bad the clutch plates were and here is what they were like.









The pressure rings are well scored.I was wondering is there anything I could do with them? as it probably would'nt be good putting in new plates with them the way they are.Would I be able to get them machined down a bit and then use a shim or something maybe?
Can you buy new pressure rings on their own?

[N00b]

^^^
"Gareth" is your man.
He's fluent in LSD wizardry.

[gareth]

Cheers N00b

well, err, they're in a mess aren't they!!!

you can get new clutch plates (with the spline in the middle) and outer drive plates (with the four 'ears') from driveandtraction.co.uk though i outstocked him last week.

The thrust plates (the big 'uns) are not available though but can be saved. They're too hard to machine without great difficulty so will need to be surface ground. an extremely precise machining operation that bares no resemblance to an angle grinder!

Either ask around the local machine shops for 'surface grinding' or pop them in the post to me and i'll do them. maybe some 30° ramps while i'm at it too
PM me if you're interested

[N00b]

Cheers N00b

Not so fast, I'm working on commission

[alync205]

Thanks for the reply Gareth.
I will have to see if anyone around can machine the thrust plates for me.Would I have to fit a shim then to take up the gap?
If I can't get anyone around to do them I will send them to you.Would the 30° ramps make much of a difference?

Thanks
Anthony

[carannc]

If it were me i would get the housing machined to take extra plates and get the ramp angle to 30, you then have a motorsport diff , in effect. Those plates look like they either have had the wrong diff oil in or been used on a track and been getting mega inside wheel spin which is a killer for plate lsds

[gareth]

it will probably only take 0.1mm or less to clean them back up. the thrust plates are a lot harder than the metal backing on the clutch plates so most of the damage will actually be metal deposited from the worn clutch plates onto the thrust plates.

the preload on the diff is formed by a system of conical springs which 'squash' by about 5mm or thereabouts. if you remove 0.2mm from this, it will make very little difference to the initial lock and once under power the diff locks itself up harder anyway, negating this effect.

of course you could upgrade to 4 clutch plates but this will make for a fairly aggressive initial and ultimate lock for a road car and for normal use, isn't necessary.

the 30° ramps will give you the same low level of lock under light loads (normal driving) but lock up a lot harder under power.

my own diff was in a very similar state and i rebuilt it with fresh faces on the thrust plates, two clutch plates (as standard) and 30° ramps and it's brill