Rust Inside Diff - Advice Needed!

[samos69]

Hi All,

A while back I bought a 2 way nismo LSD for my R32. It's sat in my garage with the backing plate on and wrapped in shipping plastic on a pallet. Unfortunately my garage is very damp and any bare metal does rust rather quickly. I finally got around to pulling the backing plate and found there is some rust on the diff

As far as I can tell it's only on a couple of bolts on the crownwheel (?) and the two caps that hold the diff in the housing, all the important bits had a coating of oil and seem fine. My question is do I pull these parts out and give them a wirebrush then reinstall? Or do I need to pull apart an old open diff I have that is full of oil and will have no-rusted parts (are the caps interchangable?) Do I ignore it and just fill it up with oil then go racing?

Here's a pic, the rust is very crumbly and would come off easily.

Also, how clean do I need to get the backing plate of old gasket goo? Completely clean, or just all major lumps taken off? And how much do I use to seal it?

Any advice is much appreciated, I'm no expert on these matters!

Cheers

Sam

[The Dan]

Step 1: Buy 2L of LSX-90

Step 2: Drive around for 100km or until the oil is at least hot

Step 3: Drain oil, wipe drain plug with magnet and fill it up with your favourite blend

Diff's are extremely forgiving, if it was a conrod bolt with rust I would be saying pull it apart.

[RB25 SKYLINE]

id be giving it a light sand with some 400 grit wet n dry then do as daniel said

[samos69]

Thanks for the replies, good to know it's not too bad. I'll have a crack at it today...

[turboedsloth]

If you wanted to get really anal you could remove the caps one at a time and bead blast them. You can't interchange caps from other diffs as they are matched to the diff housing like a girdle is in an engine.

As for the glue, scrap as much off as you can and give both surfaces a rub with an oil stone which will make it nice an clean,

[samos69]

After a scuff up there didn't seem to be any debris that could come loose so I just went ahead and sealed it up. The backing plate has a metal gasket on it which I've never seen before... just put some high temp RTV over it and torqued it up. Will fill it with oil in the morning and see if it leaks!