Benonymous

Hi All, I'm a new member and currently gathering parts to construct a md-engine car. my intention is to use all Audi parts for the powertrain. To that end, I have recently bought a used OB1 6 speed gearbox. I was originally going to go with an 01E or similar box but research showed that converting a Quattro box to 2WD only is not practical. So an OB1 cam up and I grabbed it, not really understanding the big differences between the 01E and the OB1. Anyway, finding an01E in 2WD form in Australia would be very unlikely and the OB1 will totally do what I want. The other aspect to this build was also that I would buy a donor car to get the other major components off. B8 series cars are still fairly expensive here (especially for a parts car) so I'm currently keeping an eye on the local salvage auctions. Anyway, I have a few questions that I hope the experienced members here on the forum can answer.
1. Is the OB1 transmission only suitable for engines from the B8 onwards, or can older engines be bolted up?
2. Is the Flex/Drive plate on the back of the motor different for auto and manual transmissions on the B8 series?

Thanks in advance for any knowledge you can pass on :-)

SMac770

The B8 introduced the new generation of Audi manual transmission case:
0B1 - low torque FWD (A4/A5)
0B2 - low torque quattro (A4/A5)
0B3 - high torque FWD (A4/A5 3.0 TDI)
0B4 - high torque quattro (S4/S5)
0B5 - dual clutch conversion of the 0B2/0B4 gearbox
You'll likely only find the 0B3 in conjunction with 3.0 TDI FWD applications.

Look for "audi ssp 392" in google search, read up on the Transmission chapter to read about the 0B1-0B4 manual trans intro.

The prior gen manuals were 01X (low torque FWD), 02X (low torque quattro), and 0A3 (high torque quattro). So the 01E must be even older than that. Apparently, 01E is turn of the century stuff (haha, like me).

Yes, the flywheel for manual transmission and the flex-plate for automatic transmissions are different on the B8 engines; the flywheel version also includes the needle bearing necessary for manual trans operation. But the actual flywheel/flex-plate part depends on the engine and transmission.

Benonymous

Thanks for the reply SMac770 :-) I'll start looking for the correct plate. The motor I want to use is the 1.8T but I'd go with the 2.0T also. I'm amazed that some of these things aren't more uniform I would think the parts situation would be far simpler!

FrenchToast

One advantage to the 0Bx, as far as I can tell, is that the axle output shafts are a good amount further forward. This may be advantageous if you're trying to mount the engine as far back as possible in relation to the axle. I can't say if the bolt pattern differs. Also don't know how they compare in the height difference of input-to-axle; i.e. how high the engine and transmission must be mounted for ideal axle articulation.

As for internal differences I don't know. Presumably the 0Bx offers improvements over the 01E. The 01E was used thru the '90s in VWs, Audis, and Porsches. There was even a 5-speed 01E.

As for the mounting you'll have to see. Maybe you can find a friend with whatever engine you desire and they can make a tracing of the bolt pattern on the back of the block and you can see if it is close enough to experiment bolting it up. Also check starter motor orientation and depth of flywheel/clutch assembly.

SMac770

B8 longitudinal 1.8T was:
Gen 1 - CAB (88kW CABA, 118kW CABB)
Gen 2 - CDH (88kW CDHA, 118kW CDHB)
Gen 3 - CJE (125kW CJEB)

It seems the 1.8T is managed differently from the 2.0T in regards to the flywheel. Here, there seems to be just one flywheel, and the needle bearing is a separate part number. Maybe because it was never mated to the ZF automatic, only to Audi transmissions (6MT and CVT).

B8.0:
flywheel - 06H 105 323 H
needle bearing - 079 105 313 A
B8.5:
flywheel - 06H 105 323 P
needle bearing - 079 105 313 A

Benonymous

Yes you're right, the drive flanges on the OB series make for a much more compact layout than the earlier gearboxes. The drive axis is higher and further forward by around 125mm if memory serves.

Benonymous

Thanks for the part numbers SMac770, that's really handy :-) I already managed to determine the flywheel part no but I didnt have the needle bearing one. BTW I have found a 2014 A5 coupe with the 1.8T that's coming up in a salvage auction in June. It's got the look of a perfect parts car. It's an auto but from my ongoing research, the driveshafts and other bits should be the same as on the manual car right?


sorry about the tiny pics :-P

SMac770

There are three tiers of front axles for the B8 cars (A4/A5, different axles for the B8 crossover, the Q5), differing in torque handling. But they are the same regardless of the transmissions, which are all built to the same engine mating and front axle mating specifications.

Haha, microtiny is more like it. :-)