traction additive for stock D30?

i recently changed my rear differential fluid (stock 8.25), as always i did my research
and replaced it with royal purple full snthetic which already has aa traction additive in it.
now i wanted to do my front diff (stock D30) wich takes a different kind of gear oil wich i
couldnt find in royal purple, so i have the castrol gear oil now, but do i need to add
anything to it?

You should not. The only reason to add anything to an OEM axle is because it has a "Limited Slip Differential" - which works by means of clutch packs. The additive is a "friction modifier" so that the clutches can still grab each other - not using the additive will cause the clutches to glaze and chatter (and want replacing.)

As far as I know, the only axles to come with LSD from the factory were the D35, D44, and 8.25" - in limited quantities, and in the rear only. If you have LSD in your rear axle, there should be a tag retained by one of the axle cover screws (because people should damn well put that thing back!) and the presence of clutches could also, possibly, be visually verified...

5-90

and what might this "tag" say on it?

there was a limited slip d30 that used friction plates , hydro-lok mabey?.
but this only came as o.e.m on low pinion wj's , 01-02 ?
this can be made to fit in a high pinion xj d30 but requires custom length shafts and clearancing the housing for the hydraulic pump .
we did this on my buddys xj at work , gotta love warranty parts .

The "tag" would say something like

"USE LIMITED SLIP DIFF LUBE ONLY"

Or something to that effect. That's quoting from the tag that was on on of my 89's...

5-90

very well, carry on

need4speedjp said:

i recently changed my rear differential fluid (stock 8.25), as always i did my research
and replaced it with royal purple full snthetic which already has aa traction additive in it.
now i wanted to do my front diff (stock D30) wich takes a different kind of gear oil wich icouldnt find in royal purple, so i have the castrol gear oil now, but do i need to add
anything to it?

Click to expand...

You can use the Royal Purple in the D30

need4speedjp said:

now i wanted to do my front diff (stock D30) wich takes a different kind of gear oil wich i
couldnt find in royal purple

Click to expand...

explain in more detail what gear lube and weight you are using/need and why? both axles should use the same lube with the exception if you are following mfg specs for a towing application and using synthetic 85w140..