Mopar Muscle Association UK

Ever since we got the 63 Polara, we've had a funny vibration/feeling/noise coming from the rear end when pulling away after braking, and when reversing, both more noticeable when turning a corner. It's as if you're dragging square wheels behind you. We could have sworn it was the brakes sticking, or at least brake related, esp as it's always after being on the brakes.
Another item on the list to get fixed was the wobbly pass side rear wheel, which we know isn't the wheel/tyre, so we booked it into Souther Axle Services in Watford, fearing the worst. Turns out the flange that the wheel bolts onto is 0.08" (2mm) out of square with the shaft! New 1/2 shaft please.
Now to the point. While talking about new half-shafts etc, we mentioned the 'square wheel' problem. Paul, the proprietor used his finger, his nose and experience to deduce that the axle didn't have any limited slip additive. He said that many 'Yank' owners with lsd's (in our case Sure Grip) had the same problem if not using the additive. As we said to him, we've never had the problem with our Satellite nor even heard of it. One dose of Mopar additive later, problem near-as-dam-it fixed.
Since then I read a Mopar Muscle article where they recommend using GM limited slip differential additive with Sure grips, so it must be right that something's needed.
Anyone else heard of that / used the additive?
Rob

We had a thread on here all about this a little while ago. All LSD units need an additive or an oil specially made for LSD units. We have a Brent Oils place on the riverside up here and I have always used their version which they make for tractors mainly. It costs ?10 for 5 litres of gear oil with the additive in which I think is pretty good considering what the MP or GM additive costs.

That was my thead...... I left it to the last minute to get some! I used the Mopar addative. Seems OK. But works out dearer than Daves stuff.

Thanks guys. Did look for previous threads but must have missed it.
Might have guessed we'd be the only ones not heard of the additive, except maybe the guy that put it together in the US. Supposed to be some kind of expert in these sort of things, but gradually finding out otherwise!
The little bottle of Mopar additive that Paul Letchford (Southern Axle Services, recommend him to anyone!) had is about ?6 from Jeep dealers.

Thats the one!