How much can a 1.8t 8l gearbox take?

[tom001]

Will be looking at buying my brothers Audi A3 1.8t 8L car soon but have a small question about the gear box. How much bhp and torque can they take before you start getting problems?


I used to own a 2007 Seat Ibiza Fr pushing 240bhp and around 300lbs torque from a ko3s turbo. All internals standard, just bolts on mods and remaps to get the power, same old stuff. Car was fine and never had any issues at all other than fitting a 400lbs torque rated clutch to transfer the power.


I take it that the Audi gearbox can take the same sort of power with no issues. Should also note that the engine code is AGU if that helps at all.

 

[16Klappe]

FWD, not quattro?

No problems at all, in terms of actual load going through the gearbox there is very little. On road tyres without a diff the inside wheels just spins up taking the load off the gearbox.

Prawn has a diff in his car and drives it on slicks, he has had less than 210bhp for a while now but has done thousands of miles on tracks and at the ring, he's had issues with an old box with unknown mileage which came with the Quaife fitted sheering the end differential nut, and a suspected poorly built box destroying second gear but otherwise no issues. And he puts 10x the load through his box with the slicks and diff than I ever would with 240bhp.

My huge suggestion would be to fit a KR/G60 flywheel and a VR6 clutch to the car, more than man enough, single mass and slightly lighter.

The other thing would be, if looking at a pre-facelift car upgrading to a facelift linkage. Most pre-facelift linkages are getting a bit long in the tooth now, the facelift linkage totally transforms the feel of the box.

 

[Dani_B19]

Does that with the linkages apply to s3's aswell mate?

 

[16Klappe]

Does that with the linkages apply to s3's aswell mate?

I can't believe I'm saying this, but...I don't know! I presume not though.

I've asked Prawn so will update with what he says, I guess Tuffty could pop up and tell us?

 

[<tuffty/>]

02M boxes are pretty strong... both Welly and I have over 300ftlbs going through them and 400 odd hp...

Launching kills drivetrain components... if you launch something will break...

Biggest issues with S3 (and other VAG boxes) are the diff (crownwheel) rivits and the selector forks but they can go on std cars..

<tuffty/>

 

[Alex C]

yep, shift fork went on my car at ~75K completely standard S3

 

[Powelly]

Is there much work involved swapping the prefacelift to facelift linkage? Mine on my AGU is slacker than Kyle's mum's pink bits!

 

[16Klappe]

Is there much work involved swapping the prefacelift to facelift linkage? Mine on my AGU is slacker than Kyle's mum's pink bits!

Nope easy job by the sounds of it, not personally done it myself but have a full linkage waiting for me at Prawns, just remove the entire tower and lever, all cables and the appropriate pullers and cams from the gearbox. Top it back up with oil and refit as removal.

Please don't everybody start doing it though haha!

Prawn has gone a step further and mounted his internally with the cables through the interior -

 

[Powelly]

Worth a go then! Better keep an eye out on ebay and grab it all before too many people decide to do it and prices go up haha

 

[Prawn]

swapping the linkages over is a pretty big job, the exhaust and downpipe need to come off, so the whole heat shield under the car can be removed, then you can take the shifter out the bottom. Shift tower needs to come off the box, which means losing all the fluid, then all back together, also you'd need a spare loom plug for the reverse light switch and ahve to rewire that in to work on the newer style shift tower.

Well worth doing though, I upgraded to the later style linkage with a TT shift arm on the box, and it improved feel 100x over, one of the best things I've done.

The pre July 98 AGU gear linkage is a joke, it's like stirring porridge.

Also, personally, i think o2J boxes are ****. my car is currently on it's 6th gearbox, and will be on it's 7th when I swap out yet ANOTHER dead gearbox in a few weeks time. Main issues are diff rivets blowing, but I've also blown the retrofitted bolts used on my quaife, and most recently I've ripped 2 teeth off second gear. I hate the things.

 

[Sam_]

From what I've been told it's the selector forks that are the main beef (as mentioned previously). They are pop riveted from what I've heard and the common cure is to replace them with tiny bolts and nuts (obviously with a shed load of thread lock I'd imagine!).

 

[Prawn]

Selector fork issue seems to be more 02M than 02J. Not sure if the 02M diffs are rivited or bolted as standard though.

 

[<tuffty/>]

Selector fork issue seems to be more 02M than 02J. Not sure if the 02M diffs are rivited or bolted as standard though.

Rivited mate...

<tuffty/>

 

[darren t]

02M boxes are pretty strong... both Welly and I have over 300ftlbs going through them and 400 odd hp...

Launching kills drivetrain components... if you launch something will break...

Biggest issues with S3 (and other VAG boxes) are the diff (crownwheel) rivits and the selector forks but they can go on std cars..

<tuffty/>

snapped oil pump chain tensioner on my launch which in turn bent s con rod launching any 1.8t engine is not a good thing too do faliure is certain!!

 

[<tuffty/>]

snapped oil pump chain tensioner on my launch which in turn bent s con rod launching any 1.8t engine is not a good thing too do faliure is certain!!

Not really related to how strong an 8L gearbox is though is it... sounds more like a series of unfortunate events as the act of launching won't have snapped the oil chain tensioner unless it was already in a weakened state... they are plastic... heat and oil affects plastic... I would say the oil chain tensioner snapping is an unfortunate coincidence tbh...

However... launching a car with a decent amount of power will put strain on all connected components and these cars are old with mileage... you take your chances on these things realistically..

<tuffty/>