Transmission Replacement Questions

[19birel]

Hey guys, long story short, my gearbox decided to turn into a box of marbles. Basically now I'm trying to weigh my options/figure out if there are other things I can or should do during this process. Here's a layout of my thoughts

Options
Buy a used 1.8TQ gearbox (Most likely scenario)

Swap a 2.8Q gearbox (Hoping light can be shed on this, couldn't find much info in my searches)

6-speed swap (most expensive not worth it to me at this time I just put it here because if by some miracle I get a crazy deal on parts I'd might do it)

My questions regarding those are, are there any differences between the gearboxes for the AEB cars and the ones for the drive-by-wire cars?, I know the gearing for a 2.8 gearbox is different, has anyone done this on a 1.8T with success, or can someone shed some light? I figure it's probably not geared as tall so I'd gain some highway mpg, but probably loose acceleration. Not sure if I can keep my rear diff either if I go this route.

Secondly, is there anything I should do maintenance or even mod wise while I have the car apart? My clutch has less than 20k miles on it and grabs fine, I'll be changing the fluid, in the replacement gearbox (and changing my diff fluid), and if my mounts are worn, I'll knock those out as well, anything else I'm missing? Things I should check for when buying a replacement gearbox?

Thanks!

[walky_talky20]

1) Any B5 1.8TQM gearbox will direct swap. DBW is not different in any way that actually matters.

2) Yes, 2.8QM gearbox has longer gears. Car will be slower. You do not need to change the rear diff. All B5 quattro manual trans are 3.89:1 final drive.

3) If you go 6MT (01E) you *do* have to change the rear diff as they are 4.11:1. A B5 A4 tiptronic rear diff will work for that.

4) At the age of these transmissions, I would recommend you change all the seals before you install. Output shaft seals, input shaft seal, shifter shaft seal. Way easier to do them now and they are not expensive.

[Davdraco1]

I would get whatever trans is closest to you at a reasonable price, weather it be from a 1.8 or a 2.8. I've bought two 1.8 trans used. Both cost me 100$ each. I feel like I got lucky and got a good price. But idk what a normal price is on them. I have seen 01E trans go for over 500$. And you'll need a rear diff too.

[19birel]

1) Any B5 1.8TQM gearbox will direct swap. DBW is not different in any way that actually matters.

2) Yes, 2.8QM gearbox has longer gears. Car will be slower. You do not need to change the rear diff. All B5 quattro manual trans are 3.89:1 final drive.

3) If you go 6MT (01E) you *do* have to change the rear diff as they are 4.11:1. A B5 A4 tiptronic rear diff will work for that.

4) At the age of these transmissions, I would recommend you change all the seals before you install. Output shaft seals, input shaft seal, shifter shaft seal. Way easier to do them now and they are not expensive.

Awesome, I was unaware that the tiptronic diff would work if I went with an 01E, I guess I won't completely discount that as an option. I didn't think about seals, good call, I'll definetly replace them before installing the "new" gearbox. Thanks!

I would get whatever trans is closest to you at a reasonable price, weather it be from a 1.8 or a 2.8. I've bought two 1.8 trans used. Both cost me 100$ each. I feel like I got lucky and got a good price. But idk what a normal price is on them. I have seen 01E trans go for over 500$. And you'll need a rear diff too.

A local Audi parts breaker quoted me at $400 for a 1.8T gearbox, but there are a few 2.8s being parted out that I could probably snag the gearboxes from for much less. I'll keep searching, hopefully my VW is out of the bodyshop when I get home, then I can take my time sourcing one at a good price. I'd prefer a 1.8T gearbox because I don't want to loose any acceleration, but If it pulls lower revs on the highway then the improved fuel economy will be a consolation I suppose, we'll see what happens I guess. Thanks for the input!

[Davdraco1]

400$-500$ is what local junk yard quoted me at too. Keep looking in the classified and craigslist. You'll find one. The second trans I bought came with the whole shifter still attached so I could make sure it went into every gear before I even bought it.

[GOODBYNAAIR]

Hey guys, long story short, my gearbox decided to turn into a box of marbles. Basically now I'm trying to weigh my options/figure out if there are other things I can or should do during this process. Here's a layout of my thoughts

Options
Buy a used 1.8TQ gearbox (Most likely scenario)

Swap a 2.8Q gearbox (Hoping light can be shed on this, couldn't find much info in my searches)

6-speed swap (most expensive not worth it to me at this time I just put it here because if by some miracle I get a crazy deal on parts I'd might do it)

My questions regarding those are, are there any differences between the gearboxes for the AEB cars and the ones for the drive-by-wire cars?, I know the gearing for a 2.8 gearbox is different, has anyone done this on a 1.8T with success, or can someone shed some light? I figure it's probably not geared as tall so I'd gain some highway mpg, but probably loose acceleration. Not sure if I can keep my rear diff either if I go this route.

Secondly, is there anything I should do maintenance or even mod wise while I have the car apart? My clutch has less than 20k miles on it and grabs fine, I'll be changing the fluid, in the replacement gearbox (and changing my diff fluid), and if my mounts are worn, I'll knock those out as well, anything else I'm missing? Things I should check for when buying a replacement gearbox?

Thanks!

I now run a 2.8 trans in my GTRS1.8t do I like it Yes its much better for HW driving and with a larger turbo you can use 2nd. I would say get whatever trans you can for the best deal. junk yards by me sell them for $150 and look at the partout threads should find one under $300. If you plan to stay k03 I would say try to get a 1.8t 01a thats will be the best fit for power and MPG.

Things you should do other that what you have on your list. check your CV boots, and the metal slave with SS lines is a nice upgrade. I have pics and videos of the 2.8 trans in my thread if you want more details.

[19birel]

400$-500$ is what local junk yard quoted me at too. Keep looking in the classified and craigslist. You'll find one. The second trans I bought came with the whole shifter still attached so I could make sure it went into every gear before I even bought it.

Okay then, I'll definitely focus my searches to classifieds and craigslist ads then if I can get something cheaper there.

I now run a 2.8 trans in my GTRS1.8t do I like it Yes its much better for HW driving and with a larger turbo you can use 2nd. I would say get whatever trans you can for the best deal. junk yards by me sell them for $150 and look at the partout threads should find one under $300. If you plan to stay k03 I would say try to get a 1.8t 01a thats will be the best fit for power and MPG.

Things you should do other that what you have on your list. check your CV boots, and the metal slave with SS lines is a nice upgrade. I have pics and videos of the 2.8 trans in my thread if you want more details.

The car will likely stay on a K03 so I'll try to find a 1.8t 01a, but from watching your 0-60 video the 2.8 doesn't look like it'd be terrible on stock power once the car is rolling, being able to do 60 in second would be nice haha.

I'll check the CVs and look into the upgraded slaved cylinder, if I find a gearbox cheap enough I'll try and squeeze it into the budget.