I've drained my differential twice now, once after each summer season of driving since I've owned it. It's a 2002 with 60k miles on it, the car runs perfect in all respects. Each time I drained the differential I've gotten dark black paste on the drain plug, maybe a couple millimeters thick, give or take. The car is driven very easily. It's hard to tell if I'm getting alot of wear or if it is just sludge from the previous owner. I'm only putting about 5k miles on each run, one season's driving. I've used Amsoil severe gear fluid each season, I'm not sure what the previous owners used. I just sent off my sample used fluid for analysis, so we'll see if it is wear or just sludge.

I'm curious to know what others are finding when they drain their differential fluid, are you seeing much accumulation on the drain plug ?, I'm not seeing any big particles, only very dark paste attached to the magnetic plug, rubbing it between my fingers it feels just like grease, though it is very fine metal wear. My diff. feels fine, no odd noise or odd behaviour.

Thanks for any replies on this.

 

About the same as you if im interpreting it right. I have pictures somewhere of the drain plug after my changes and mileage noted. That was on Motul 300v 75/90. Mostly dark grey paste.

one season. roughly 14000km I believe.

 

Ah thanks for the pictures. Yeah mine looks like yours in terms of colour , thickness, and consistency, but the paste-like wear material covered the entire width of the drain bolt, so wider than what is shown in your photo. In your photo the material is only as wide as the magnet, mine covered the full width of the bolt, the recessed area was completely covered. Thanks for sharing that info.

 

I think you are just cleaning up sludge left behind from the previous owner. If you could have seen the OEM fill drain plug, you would have been shocked. You will always see at least a little paste on the plug though.

If you want to clean it up faster than you currently are, then add 2 ozs of Auto-Rx to the current fill. Drive it for 1000 miles. Drain it on jack stands. Fill it with non detergent SAE 20 or 30 engine oil or turbine oil. Run it on jack stands for 15 minutes in 1st gear idling (no load). Drain it and then fill it with Amsoil SVT again. You will have little to no paste on the drain plug ever again.

 

It's normal wear of the diff. You'll see that no matter what kind of fluid you use. I use Amsoil severe gear lube and I still see that every time I change the diff fluid. the only way you won't see much of it it's if you drive the car like a grandma and change the fluid more often, which is a waste of fluid and a waste of s2000 if you don't drive it like it's meant to be.

 

My guess is that it is a water and oil emulsion caused by sweating from the small amount of atmosphere that exist above the fill. I don't think there is anything you can do about it and probably should be considered normal. Changing more often is not going to change this since you are re-introducing another fresh atmosphere with each change. Humid parts of the country would be more prone to this than the arid parts.

 

Totally agree. Paste is normal. It's the chunks and metal shavings you don't want to see

 

Just dumped my 3rd fill of Motul 300 75/90 from the diff - Had more than my avg amount of mileage @ 17500 km (including two dragon trips and a track day). However even having more time on the fluid, the paste on the diff was slightly less than the last 3 fills which seemed to have had stabilized.

I tried the Amsoil Severe Gear 75/90 since it was cheaper and readily available and have heard good things about it. Does anyknow know what the severe gear is? the Motul apparently was ester based - for 25.xx a quart id hope so.

PS, old diff fluid smells like an olive bar

 

I'll see how my used fluid analysis looks when it comes back.

Amsoil is a group 4 pao based synthetic with some esters added, but not quite a full group 5 like Motul claims to be or Redline claims as well.

Thanks for all of the replies , hope Indymac is right on his opinion

 

Magnetic sludge



It is fun to finger paint with metal



IIRC this was after 25k-30k km, 4.57 diff with Amsoil SAE 190.

You can see the ring through the drain hole.
Drain the oil warm/hot, wait for an hour or more and get the smallest flashlight to inspect the ring on both sides of the tooth.
Turn one wheel to turn the ring.
Use safetyglasses because you may get another drop of oil.