Automatic trans does weird things, drives then doesnt?

[scabzzzz]

Car in question: 1987 325
I acquired an E30 from someone that didnt give a shit about it anymore. I sourced her a transmission as the last one went out on her. My buddy had a low mileage (~60k) eta trans, so he gave it to her. She had it installed, to which she installed the correct driveshaft for it (eta shaft). It drove great, engaged gears very snappy, like normal. Now suddenly from a cold start, you start it up and drive it around just fine. Then once it starts warming up, it doesnt really engage gears any longer. 3 minutes or so is all it takes. Checked the fluid, seems good. The trans was just installed, but not by me or any of my friends. Some rando shop. The auto trans was in good working order prior to its removal from the original car.
Another note: When it wont engage, it starts making a noise that sounds like a whining starter, almost sounds like a power steering whine. Its also weeping fluid slightly from the large fluid lines, but not much.
No clue where to begin. I've avoided auto E30's since the very beginning and have zero knowledge on common issues. Tried searching, but had no clue what to search for.
Considering just taking it to a shop to not deal with it. Please no comments on swapping to manual trans. I'd obviously do it if I had space/time/money/etc.
Where you at Mr. Jim Levie

[SpecM]

what kind of fluid was the trans filled with?

[Farbin Kaiber]

Was the cooler and lines flushed when the unit was installed? What was the internal failure of the old unit?

I'll bet there is a bunch of clutch pack rubbish bedded into the discs inside this unit.

Flush it, then, if there is still an issue, swap it out again.

http://www.bulkpart.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=2&Product_Code=M465F18&Category_Code=cooler-flush&Product_Count=1

[scabzzzz]

what kind of fluid was the trans filled with?

I have no clue. From the drips, it was pretty clear and hazy. Not super light brown lik new motor oil, but lighter. Thought auto trans fluid was reddish?

Farbin - Maybe? Probably not? Dont know for sure. I wouldnt recommend her to any of my personal BMW friends. Thats a good point though. I can give that a shot. Id only be out ~10 bucks. The last transmission probably just took a major dump. It drove for a while, but going up hills it would buck and shake like it was slipping really bad. Then just finally stopped moving the car.

[Farbin Kaiber]

Your description of the fluid sounds like gear oil.

[u3b3rg33k]

I'd have to personally rebuild an automatic before it ever saw the underside of my e30 again.
I wore out my 1st gear clutch pack, and then promptly bailed on slushboxes.
It just wasn't worth it to me to rebuild an auto, since I dislike them so much, but I can't imagine it would've been too terrible of a job to do.

4HP22 rebuild write-ups are out there.

As for fluid, my research has told me that some slushboxes are very sensitive to what fluid is run in them. Choice of gear oil in an MT is much less important than having enough oil. The fluid in an auto transmits power, lubricates, and cools.

If you don't run type F fluid in old jaguars, say good bye to your transmission lifespan.

[scabzzzz]

Thanks guys. I really didnt know the first step to troubleshooting or getting more information, I'll try all the things above when I get to the car again (it's being stored in another city at my Mums).
Much appreciated.

I'll try draining the fluid, and refilling with OEM spec fluid. Will also go ahead and flush the lines. If that doesnt fix it, I'll probably store the car somewhere else and wait a few months to drop a complete known good working engine and trans, and get the 5spd swap over with.

[u3b3rg33k]

Drop the pan and take a look.

[scabzzzz]

Drop the pan and take a look.

Okay. Ill take photos too. Because I'm not really gonna know what to look for.

[Farbin Kaiber]

Mushy metallic material in the bottom, full metal shavings, etc.

[wodcutr]

It sounds to me like you might have a bad torque converter. The tranny might be fine, but the converter is what is making the whirring noise as it has turbine like blades in it that converts the motor speed to the tranny. I would check that out first.

[u3b3rg33k]

It's a lot easier to take the oil pan off than to pull the transmission.

At least, last time I checked.

[SpecM]

new fluid should be a vibrent, rosey red color. Not clear-ish.

Farbin has a good point, the old tranny prob puked clutch pieces all inside the lines. Flush and change the filter.

use Dextron III for fluid