Friction Modifier Questions...

[ns954]

My 2000 F-350 DRW Dana 80 axle had the infamous "chatter" when making tight turns.I changed my oil to synthetic Royal Purple 75W-90.It supposedly has limited slip additive already in it.Still had the chatter.So,i added a 7 ounce bottle of Trans-X Limited Slip Friction Modifier to the oil.My chatter seems to have cleared up.If the rear end oil is oversaturated with limited slip additive,would i know it?What would be the signs?Thanks everyone.

[Lord Tauk]

I used synthetic in something else that supposed to have the modifier in it, plus I added the trans-x too. I haven't had any issues in over a year.

I would have used the 140 weight and not the 90.

[ns954]

I started to use 75W-140.Then i ran across Ford TSB 04-16-4 dated 7/30/04 that recommended 75W-90 for the Dana 80.

[Lord Tauk]

Sounds cool