How long is ok to drive without friction modifier in a trac lock equipped diff

[lazybummm]

I have a 98 XJ with a Chrysler 8.25 with a trac lock lsd. I had my mechanic change the front and rear diff oils today, and I didn't remember to check for whether it had a LSD nor did my mechanic.

Anyway I heard some weird noises coming from the rear end, so I jacked up the car tonight and spun the rear wheels and found out that it does have a LSD(both wheels spinning in the same direction), and I'm sure my mechanic didn't put any in. I will go and buy some friction modifier tomorrow morning and put it in.

I drove probably like 150 miles today without any modifier, the weird sounds happens with some turns and not others, that or it was just louder in some turns so I could hear it.

Is there anything i should be concerned out? should I try to siphon some fluid out to add in the additive or not worry about it?

Also if the LSD burns out, the car still drives fine right? just completely open?

Thanks!

 

[JJacobs]

That's right, the part that makes it a limited slip is basically just a set of clutch packs behind each diff side gear. The spiders are the same as a normal open diff. In straight ahead travel the side gear clutches are just sitting there with no relative motion- you'd have to circle a parking lot for an hour to really hurt anything, if even then. Just put some modifier in and do figure 8's for a minute to get it circulated between the clutches and the noise should go away.