zeroptzero

Hey Jack, how much can you overfill these diffs ?. The very most anyone would put in there is one quart, at that rate you are only about .20 quarts over , give or take ?, and then if you did have some fluid spilling out you are going to be maybe .10 quart over ? est. Would that be enough to cause issues ?.

One reason why I ask is because I used a funnel and tube to fill my diff this winter, I dumped one bottle into the funnel and then allowed fluid to drain out of the fill hole. It was much easier than sitting there pumping molasses (even with heating up of the bottle before hand). Given what you just posted I might just open up my fill bolt and see if added fluid comes out, but I may do that in warmer temps. Good to see your opinion on this matter.

INDYMAC

I don't know how much you can fit in the diff. But I suspect you could put a whole quart in there if it's parked on a hill. Add that to fluid expansion and you could have a whole bunch of air bubbles.

If you want to guestimate how much to put in there, fine. But when you get the car to level ground, just pull the fill plug and let it drain until it stops.

starchland

Was the diff sitting for awhile before the sample was taken?

sillyboybmxer

That was one of the concerns i had and made sure to ask,...they say at the lab that they do not see much of a difference in readings at all given cold/warm. It was still taken from the mid stream of the drain process.
The differential was cold when I drained it, normally I do it after a drive but I had did all the fluids that day and said "F it, I'll just let it drain for an hour....and it did)
The car was as level as it could be as it was done in my garage where it always has been with the same 4 jack stands I always use, it is possible the stands were a notch off but I doubt that would cause anything.
With the amount of fluid left, and by what was draining out of the differential while trying to get the fill plug in and what was left in hand pump hose I would suspect I did NOT get 4 fluid oz or so(just a guess by looking at what was left)
I always have about that same amount left with all the changes, but like I said I always struggle with getting the full plug in but it was still draining when I got it in
And the magnet, I always check it and wipe it clean. There was a slight grey film, no chunks. It looked like what I consider usual

SpitfireS

As far as I remember you get an oil level that is halfway up the pinion when you fill-till-overflow.
IOW the pinion-ring contact is not fully submerged and not dry.
It's not that the ring gear has to draw the oil up.
Overfilling in that scenario will turn the pinion-ring contact into a giant oil throther - like in the gearbox.
(the gearbox has a pump to pick the oil up too)
IMO a slight overfill does not harm the S2k diff.

There is an oil passage from the main pinion bearing to the rear at the bottom of the casting AND at the top.
I think some of the oil that is picked-up by the ring is thrown through that top hole to refresh the oil for the main pinion bearing and it levels throught the lower passage.
That way there is some kind of oil flow through the diff.

zeroptzero

Since you had a usual amount of paste on the drain bolt magnet that is a good sign. That is where all of the bad stuff collects. If you had significant wear you would see it on the magnet.

I think you will be fine, refill with the fluid of your choice and don't sweat it.

sillyboybmxer

After I contacted Puddydad!

zeroptzero

Spill the beans man

Barring any stange noises or odd operation of the rear end I think you will be fine.

sillyboybmxer

I wish I had ordered something.
More of just an options for me/prices type of contact.

sillyboybmxer

got another sample done.
This one has about 5 months of daily on it and about 75 autox runs and a track day with 4 20min sessions.