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Discussion Starter · #1 ·
Hey y’all. I have a 2002 Passat 2.8 L 4motion.
I have the transmission out and I’m currently looking for a replacement. Was wondering if I could swap the same transmission from an Audi.

what would happen if I swapped the transmission and the codes were not the same,
I wouldn’t mind if the gear ratio was just a little bit different.
my transmission has a code : FAS.
the Audi trans is an : FEP
 

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Discussion Starter · #2 ·
The backstory is my passat has 185xxx. Over the period of about 6 months the transmission started slipping. At the beginning I changed the trans fluid and filter to see if that would help. It slowly started getting worse to the point going from reverse to first gear would hesitate and take a few seconds to finally go into gear. The trans progressed from that point to not wanting to shift from 1st to 2nd without hesitastion. It was a real pain in the but at the intersection of stop sign. After that traveling to work the trans would kick itself into limp mode. I would pull over and reset the car and continue on. I remember on a couple of occasions hearing grinding noise from the trans areas.
I can’t remember if it was in neutral and cold starts or when…
Finally the car would slip so bad it was no longer driveable.
before I pulled the trans I pulled the codes.
they were.
p0741, p0734, p0735.

I don’t remember the car having and issue in 4th and 5th gear.
but I know the torque converter is bad.
What are your guys thoughts?
 

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Discussion Starter · #4 ·
Another thing i did not notice the first time was that the tailshaft is different on the FEP compared to FAS transmission.
What do you mean electrical component locations like the valve body? As far as the six speed swap goes that’s not some thing I’m really interested in at the moment.

When I separated the transmission from the Engine block the torque converter was a pain in the butt to pull out so I’m assuming that is where my issue lies… For the p0741 code.
The research I’ve done suggests gunk flowing around the transmission pump can cease the two together. Also the torque converter seal going bad…. I think I’m going to lean towards a rebuild of the transmission and do it myself I was scared at first just out of ignorance but really it doesn’t seem that hard. So next step is going to disassemble the transmission and take a look at the internal parts to see if a rebuild is viable.
As far as the P0735 and P0734 codes with that be caused by my clutch packs going bad?
I remember driving the car and it being fine especially going 70 or 80 miles an hour the only problem would be when the computer check the car in a limp mode.
And later on the really bad slipping.
 

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Discussion Starter · #6 ·
It could be the transmission oil pump bushing is shot. That's a fairly common problem and would explain the leak and why the TC was so hard to remove. I can't remember the details but if it's bad enough you might need some machining done and/or an over-sized replacement bushing, new TC or oil pump.

It could be the transmission oil pump bushing is shot. That's a fairly common problem and would explain the leak and why the TC was so hard to remove. I can't remember the details but if it's bad enough you might need some machining done and/or an over-sized replacement bushing, new TC or oil pump.


My plan is to just replace the pump all together.

I’ll definitely take a look to see what the bushing looks like!
 

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Discussion Starter · #9 ·
So finally got around to pulling the transmission apart. Pretty sure I found all the culprits for the codes. First off was that the oil pump bushing had spun out. It was freely spinning and chewed up good. The second thing was the sleeve/bushing on the F-drum had been pushed down. That explains why in the morning I could drive for a good amount of time before the car kicked it selves into limp mode….
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Discussion Starter · #10 ·
I found an 05 FAS trans that was lower miles (according to a vin check) at the pull yard. I pulled that apart and it looks really good, you can still see the writing on the clutch disks and The f-drum is still good, so the plan is to order a new torque converter and upgrade the pressure regulator valve on the valve body and throw everything back in the car.
here are some of the links and videos I followed that helped me out.





 

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Discussion Starter · #15 ·
Ok so got the car fired up. But having a couple issues. The only check engine lights are for 02 sensors.
The car will not shift down into 3rd or 2nd on the gear selector. It gets held up. Shifts through park-4th fine…

The trans does not engage in any gear.
What am I missing ?
 

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Discussion Starter · #16 ·
I’ve added only 4 quarts of fluid besides what was in the TC. And can’t add any more… I’m prettier sure I set the TC onto the pump correctly before I bolted the trans up to the flywheel. But something is def not right.
 

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Discussion Starter · #21 ·
So there was transmission fluid in the lines going to the radiator… I initially put in 4 quarts then let the car war for a couple of mins. I didn’t let it get up to temp before checking to see if I needed to add more. It was at 90 degrees before I checked to see if I need to add more. And a bunch of fluid came pouring out. I’m pretty sure i have the TC lines up properly. It was a used TC so maybe that was the issue idk. The pump bushing was in great shape so I suspected the tc was good.
here ia the pic of how the tc is mated. View attachment 107159
 

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Discussion Starter · #26 ·
So with the trans and engine separated. I slid the tc back… 3 clicks. Then mounted the trans and engine together, threaded a couple bolts on the bellhousing.
At that point I made sure the tc was still In The same position, looking through the speed sensor hole. Then lined up the flywheeland torque converter. Then put the flywheel bolts in.
what am I missing here.
 

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Discussion Starter · #30 ·
I’m thinking there is a loss of pressure somewhere if it’s not making it back through the top line. The question is where. I’ll pull the valve body tomorrow. And if that ain’t it. I’ll pull the tranny again. And pull apart the trans to inspect.
thanks for the help brother PZ
 
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