Brake Cleaner to Clean Inside the Differential?

I'm getting ready to change my rear differential (D35) oil ... going to put in Redline 75W-90 GL5 Synthetic.

I'm wondering if I should clean the gears and bearings inside the diff? I've heard of people using WD-40 or Brake Cleaner.

I think WD-40 sounds like a bad idea, because a small amount of it will stay in the diff case and "dilute" the good gear oil.

Is Brake Cleaner ok? I'm worried it might leave some kind of invisible residue behind that might break down the gear oil.

Or ... should I just drain, wipe out the obvious crud at the bottom of the case and reassemble?

Any other advice?

Brake cleaners fine, it don't leave residue at all.

Brake Cleaner doesn't leave reside at all, TRUE.

But, its a powerful solvent that could mix with remaining dirt and oil in the differential and leave some sort of bad concotion of bad oil and dirt left behind to dilute the new oil.

If you have the entire differential apart and can make sure you can wipe all the old dirt/oil off, than yea, brake cleaner should be no problem. If your going to spray brake cleaner into an assembly, and have it mix with oil and dirt and only part of that oil and dirt is going to drip out, with the rest remaining behind, WELL I'M NOT SURE, BUT I DON'T LIKE THE IMAGE THAT CONJURES UP.

If I was going to use a fluid to clean the interior, it would be something I knew was compatible with the oil. I don't know if WD-40 is, but I'm sure its more compatible with Diff Fluid, than Brake Cleaner is. A squirt bottle of diff fluid and toothbrush might clean that diff real well.

I'd clean the differential as best I could with rags and then just fill with the new oil. If you think the differential is dirty enough, change the oil more often, fresh oil will clean out the dirt.

i cleaned out my front diff with like 3 cans of brake cleaner when i changed my axle seals and no harm done.

Brake cleaner is perfectly fine to use I have used many times on gear oil changes. Plus it's fast dissolving, just spray it on the floor and watch. If you do spray it and dirt falls it was already in the diff. to begin with. Spray it generously and get all the crud out of the bottom with a few rags. Just make sure you clean the bottom out real well.

Spray it out with air when all done cleaning it.