Wrong transmission fluid?

[thatkidarlen]

So to start, I bought my first car, an 87 325is, with 20 years of service records ( YEAH LUCKY ME! :p )

So the first owner had a new transmission in 97 and they put in ATF. The second owner took it to a shop where they drained the fluid and put in gear oil (This was in 2010).

My problem is that the transmission doesn't have a sticker or any sign that it once had a sticker.

I should also mention that I'm pretty positive I need new transmission mounts (I'll probably go with condor speed shops mounts), I have a bit of play in my shifter, and my transmission has a small leak at the selector rod seal. I want to add fluid for now until I can get the seal and mounts.

So what would be a prominent sign that I have the wrong fluid in there? Is it detrimental to use gear oil instead of ATF?

[jlevie]

As long as all of the fluid in the transmission was drained it doesn't matter which fluid you fill it with.

[AndrewBird]

I think the OP just wants to top it up until he has time to fix the seal and replace the fluid then.

Mixing ATF and gear oil is probably a bad idea. I would try sticking your finger or something in through the fill hole and see what fluid is in there. ATF will be red, gear oil will likely be darker and green/blue/gold.

[amcink]

I did this past weekend with no sticker on transmission and used Redline MTL 70W80 GL4
To my surprised there was no oil in the transmission I drove like 300 miles (city driving)with out oil; and the transmission now shift like a butter. Before the gears were hard to shift; I'm impress on these 5 speed trans they are a beast.
Lastly It was easy to fill it back through the top where the shifter is; take the boot and rubber cover or any padding off and then get a funnel with about 4 to 5 feet hose and fill it in that way

[thatkidarlen]

As long as all of the fluid in the transmission was drained it doesn't matter which fluid you fill it with.

Really? Sweet. That means that I should be fine to add the same gear oil that the second owner had put in.

I think the OP just wants to top it up until he has time to fix the seal and replace the fluid then.

Mixing ATF and gear oil is probably a bad idea. I would try sticking your finger or something in through the fill hole and see what fluid is in there. ATF will be red, gear oil will likely be darker and green/blue/gold.

I jacked up the car this morning to see how low it was. Seemed really low, but it was a bluish/gold color. Plus it smelled really bad.

I did this past weekend with no sticker on transmission and used Redline MTL 70W80 GL4
To my surprised there was no oil in the transmission I drove like 300 miles (city driving)with out oil; and the transmission now shift like a butter. Before the gears were hard to shift; I'm impress on these 5 speed trans they are a beast.
Lastly It was easy to fill it back through the top where the shifter is; take the boot and rubber cover or any padding off and then get a funnel with about 4 to 5 feet hose and fill it in that way

I wish I read this before I went and bought a pump. But I think I'll drain my fluid once I get the seal and mounts and then I'll fill it this way with some redline.