Transmission noise - Help needed

[TernandoFoledo]

Hello everyone! How are you?
Thanks for taking your time to read this and try to help a fellow in dispair. I'm literraly losing my mind with this, so sorry if it gets a little long.

So I have an E12 and swaped a M52tu (e46) and a Getrag 250 (e36) into it.

The gearbox was used befote by a Drift Driver, but was apparently good to use, so i didnt bother, but as soon as we started using the car, 2 wierd noises came up.

The 1st one is a "round humm" whenever i'm idling and with the clutch depressed (no pressure on the pedal), and disapear when i press it down.

The 2nd one is in moving, it whines like a MF supercharger. It whines hard from 1st to 4th, and in 5th is almost quiet. Also, when in a downhill, if I get the gearbox in gear, but also press the clutch, the car whines. If i take it to neutral, no whining. Clearly something is wrong haha

Here is a video from the 1st noise (sorry its in portuguese, but i start it with the clutch pressed, and then release it, so the noise can begin):
https://youtu.be/1tfDWZKU0YA

Here i have a video of this 2nd noise: https://youtu.be/wvMF6c6H60Y

Things to have in mind:
- we sent the gearbox to a shop and they told me that the previous owner used it withouy oil for a while (allegedly) and it removed some of the chrome over the gears, so it could make some noise - is it even true?
But they also said that it wasnt a problem and the gearbox was in great shape, only needing to replace the bearings - 6 in total, so we did it.
We filled the gearbox with Motul ATF Dexron III oil. 1.5L almost.

- we changed the bearing that goes in the flywheel as well, but didnt change the trownout (clutch bearing) and the fork has a spring that's not original - could it be doing something?

My first thought is that the shop riped me off and didnt changed the freaking pilot bearing, that my research led me to think to be the problem, but I hope to hear from you all to try to solve this.

I'm seriously in dispair.

Thank you very much!

Best,
Fernando

[TernandoFoledo]

The post seems to be gone (disapeared the first post) so I will repost below. If it comes back, i will delete the exceed one

- - - Updated - - -

The post returned, so I cleaned it.

[shogun]

I takes time that the posts appear when you are a newbie, posts must be manually approved by a moderattor, that is the forum software spam-o-matic

[TernandoFoledo]

Update: sorry, I made a mistake. When I mention Pilot Bearing, I mean the Input Shaft Bearing. English is not my mother tongue and in portuguese, we translate the ISB for something really close to the PB.

Ps: I didnt update the post due to the problem I've mentioned in the begining of the post. Didnt find any rules, but if this isnt cool, I will try to update it without a problem

[TernandoFoledo]

Ohh sorry!
I will delete this post. Thanks to inform me!

- - - Updated - - -

Actually, can you delete it? It seems that I cant :x

Sorry for the trouble!

[shogun]

I will fix it now and merge the 2 threads and delete double posts. After you got 10 posts, there is no need for manual approval by a moderator.

[TernandoFoledo]

Oh, i see. Thanks a lot Shogun!!

[XnWarden]

You bought a used transmission from a "drift driver"... Im sure that thing has been used and abused. Check the fluid and see how it looks.

Sent from my VS987 using Tapatalk

[TernandoFoledo]

Yeah, i know it might be abused, but they said it looked pretty good for the age and background.

The fluids were changed a week ago and nothing changed. We even put Militec in it to try to help a little. Do you think that I need to recheck it?

When we got it, it was laying for a while, so it leaked and what we saw from what it had in (a year ago) was a black gooye thing, but we changed the oil for atf bmw specs and at the shop the oil still looked good.

I understand that it had no care. Do you think that even though it could be just a junk tranny?

[TernandoFoledo]

Anyone with any experience in a case like this?

Tomorrow I will be going to the gearbox shop that "fixed" it and wanted to be prepared.

If it trully is the ISB I will not leave there until they've fixed it ._.

[TernandoFoledo]

Ok, so we went for a new gearbox. We've changed it, but the noise is still there, just lower. It changed, but its the same, if you understand what I mean.

We used the same oil as before (MOTUL MULTI ATF DEXRON III).

I think I forget to mention, but I have a "singlemass flywheel" - it was custom made using the same measures of the original one, due to the fact that my dualmass flywheel was boken when I got it.

I also have poly engine mounts - some people said it could be related.

I going for the 3rd gearbox now, to try to isolate any of those 2 noises.

[hli]

1st noise may be throwout bearing if it goes away immediately with clutch pedal pressure. If it only goes away when the clutch is fully depressed, I would suspect something with the input shaft.

Are you using stiff motor/trans mounts?

[TernandoFoledo]

About the 1st noise, I think that too, but the 1st geatbox wnt to the doctor and changed all the bearings and improved 0, literally.
The 2nd one came without a history, but when installed made the same noise, but lower. Even in this case would you suspect the bearing?

About the mounts:
My engine mounts are Poly. The trans are OEM.
I've looked into engine mounts to check if I would find something, but wasnt so lucky. Do you think it could be that?

We ran an stethoscope to it and clearly the sound is coming from the gearbox in all cases. Could it be just resonating there, but the origin be elsewhere?

[TernandoFoledo]

So we got to the 3rd gearbox.

No wierd noises! Only when reducing to 2nd gear, but i think some noise in this gear would be normal, due to the "engine brake" force it does.

But I got a new issue: when driving home, suddenly the gearbox and the engine "disconected", it start to run loose and there were no traction anymore. We waited, the traction came back, and we bled the clutch lines, trying to see if it was too tight (and probably is, my clutch engages soon in the pedal), and came back to the road, but again, in like 10 minutes, it lost the traction again, but this time seems to be for good (we waited a while to see if it would come back, but nothing...)

Now the car went back to the mechanics to check what the hell happened.

Any clues? We are betting in the clutch or plateau getting hot due to the lack of space in my clutch pedal (remember it engages really soon).

Any clues?

Thanks a lot!