Has anyone seen differential fluid turn black

[sti774]

in 4 days??

The pic below supposedly shows my rear diff fluid after only 4 days and fewer than 500 miles.

Just weekend driving and a couple round trips to work.

There were no metal flakes in the fluid or on the magnet on the drain plug.

Any ideas what could cause this?

Thanks!

[nhsilversti]

was all the old fluid drained? you say supposedly....you didnt change the fluid yourself?

[sti774]

was all the old fluid drained? you say supposedly....you didnt change the fluid yourself?

No, last Thursday I went in to the dealership for the 60k service. The diffs were on the invoice as being serviced and the fluid being replaced.

So I'm going under the assumption that it was in fact changed. If nobody has any ideas how it could turn black so fast, that may be my evidence that it might have gotten skipped at the service. I just don't know enough about cars to be able to rule anything out.

[cuda6666]

They skipped it.

[chaos4NH]

They skipped it.

Like he says...........................................

[nhsilversti]

are you sure the "new" sample is the exact fluid they used?

to me the "old" cup has a very dark green color

OR
yeah, it wasnt done

[sti774]

are you sure the "new" sample is the exact fluid they used?

to me the "old" cup has a very dark green color

OR
yeah, it wasnt done

No, honestly, once I hand them the keys and the car disappears into the garage, I have no clue what they do. For all I know that black cup could be one that they keep in a cabinet and pull out when needed

I *hope* that isn't the case, but this is a really weird situation.

This all started because I began hearing a strange noise after I got the car back from the 60k service. When I have the steering wheel over for a tight turn, like a parking spot, in either forward or reverse gears, there was a sound that I can only describe as the car "groaning". The only thing I could liken it to was that I used to drive a Jeep offroad and the drive shaft angles would be too steep from the transfer case they'd start to bind. The car definitely sounded like it was laboring to make a slow turn.

The service manager got involved because I told the mechanic to do what was necessary because safety comes first in my book, and I wanted to be sure everything was OK before this weekend's track event.

That's when they opened the drain plug on the rear diff and this black crap came out. My initial thought was that the 60k mechanic had put the wrong fluid in there, it had overheated and burnt or something because it really did smell burnt. But the service manager said no, he felt the fluid between his fingers or something and it's the correct stuff. I also checked the invoice that I had from the 60k service and the invoice that I got today for the refill, and the "part" number does match for the fluid. For what that's worth.

Then I suggested that maybe it wasn't actually changed at the 60k service to which the service manager said that the drain plug definitely had signs on it that it had been removed. I asked "removed 30,000 miles ago, or removed last week?" and he asserted last week.

So that's pretty much all I know.

One of two things is going on: the rear diff is really f'd up and burnt the fluid in 500 miles or they skipped performing the service.

Either way, I think what I'm going to do is take it back in on Friday after putting a few hundred more miles on it and have them drain it in front of me. If the fluid comes out black, bad news; if it comes out pink or whatever, then they owe me the $100 for today's flush because it should have been included in the 60k service I paid for and I look for a new dealership for future service heh.

Thanks for the input so far guys!

[962porsche]

i would say no they did not change it . subaru dealer should be using there own subaru fluids it is just alittle darker than that your showing as new fluid in the cup . if your having some one service your car its a good idea to take some white model paint and put a dab if it on the edge drain plugs . alot of dealers pay there techs on a flat rate bases . to make money a bad tech will skip things like that becouse he will get paid .3 hours for not doing a thing .

[nhsilversti]

what dealer is this?

i am going to assume you have an sti. slow speed tight turns and noise are very common and normal, it is the center diff making the noise most likely. but let me also say i just replaced a rear diff on an 04sti with 80k because it was "popping" when turning at slow speeds, the LSD needs rebuilt.

[sti774]

what dealer is this?

i am going to assume you have an sti. slow speed tight turns and noise are very common and normal, it is the center diff making the noise most likely. but let me also say i just replaced a rear diff on an 04sti with 80k because it was "popping" when turning at slow speeds, the LSD needs rebuilt.

Singer Subaru in NH. I've had very good service there up until possibly now. I don't want to jump to any conclusions which is why I figured I might as well ask if there was any possible way that fluid could have gotten like that so fast.

I agree, I'm very used to the various normal noises that it has made over the past 3 years, and this one is really out of the ordinary. Something underneath is definitly not happy anymore; I just don't know what

[CP]

Burnt smelling fluid is bad/old fluid. Assuming they changed it recently, whatever comes out should be clean and smell like gear oil, even after several hundred miles. For a track car, you really should be changing the diff and trans fluids every few events in my opinion. I do so in my SM every 3-4 race weekends. I change the oil every other race weekend (which is basically 6-8 sessions). Overkill, yes, but it's cheaper than a new/rebuilt trans/diff. Redline and several other companies make much better quality fluids than your dealer is putting in there. You may want to look into a different gear oil that won't get cooked as quickly.

[brucesallen]

Have you owned the car since new? It looks a little like Red Line Shock Proof transaxle fluid for race cars that is blue. If that was in the previous change, the mix of the new and leftover old might look that color.

[sti774]

Have you owned the car since new? It looks a little like Red Line Shock Proof transaxle fluid for race cars that is blue. If that was in the previous change, the mix of the new and leftover old might look that color.

I have owned it since new and have had Singer Subaru perform every single recommended maintenance.

The colors in the cups may be slightly off; the flash went off for the pic and may have distorted the colors a little.

Mixing could be a possibility, if the fluids are different colors which I didn't know; thanks for that idea.

[jlwhorf]

The Singers live in the same town as me, you want me to tell you where they live so you can pay them a visit.

All kidding aside, they do have a pretty good reputation in town, alot better than when commonwealth owned it.

[boltonite]

Perhaps diff "serviced" meant opening the fill plug and "replacing" whatever fluid was needed to top it up? My mechanic does that all the time!