AW4 grinding??

I have a 96xj 4.0 242T-case d30 front, D35 rear. I was at a stop light, when I started to go, a grinding noise from somewhere in front of me, then stopped. It was in sync with RPMs. Nothing happened for the next 5 miles, when I got to my house. Checked the fluid, just had it changed, but had odd color to it, though still red. Is there anything else it could be and what/how should I check?

Two questions to ask first. Did they add the right fluid? Should be using Dex III.

Also check for antifreeze/coolant in the T fluid? Describe the odd color please!

Also check the front of the engine, fans, pulleys, fan clutch, water pump and idler bearings, power steering for grinding noise.

Could it be brake noise?

It had a light brown tinge to it, the bill i received had the correct fluid listed.

I cant reproduce the noise, and also I think its just me, but the brakes feel stiffer.