How to :BHW 02x swap

devon1996

Well-known member
Joined
May 7, 2020
Location
Denver
TDI
08 A4 tdi swap
In the process of swapping my a4 to bhw I figured out a lot of stuff that would be useful for other people doing manual swaps on the bhw.

First off is the pilot bearing. The snout of the bhw crank is shorter and with a 240mm clutch and 02x spacer the pilot bearing doesn't really reach the input shaft. I've seen adapters and also people putting the needle bearing in halfway. My solution was a oilite bronze pilot bushing. It's from a chevy 2.8 part number is PB652HD. Works perfectly and sticks out far enough for good engagement of the input shaft. I have no issues getting into gear.

Flywheel and clutch. I used the stock 2.0t DMF. The 2.0t clutch wasn't sufficient for the diesel torque so I had to figure out a new solution. The RS4 clutch is the go-to upgrade for these cars but it requires a special flywheel. I didn't want to spend the money on the flywheel so I figured out what the RS4 clutch needs to work. The key is to take 4 mm off of the surface of the pressure plate. It cost me $120 to get the PP machined to the right height. I tried to shim the plate originally but it hits the case so you have to machine it. The clutch kit it's self was $100 used with 3k miles. The car is turned up to maximum torque and I haven't even gotten the slightest indication of slippage and the engagement is smooth and light.

Starter wise I used the 2.0t gas starter. It isn't great for when it's really cold because it turns over slower than I'd like but it always starts.

Gear ratios on the gas 02x are sufficient for the bhw. I hunted down a HCK 6th gear for highway cruising. It has a .575 ratio and was $460 from Europe. I haven't installed it yet but it will yield 2400 rpm at 85 mph vs 3000 rpm now. Mileage is good still with 36-38 mpg on winter fuel with quattro and snow tires.

I used the factory thick spacer plate from the 2.0t.

And there you have it.
 

TDIMeister

Phd of TDIClub Enthusiast, Moderator at Large
Joined
May 1, 1999
Location
Canada
TDI
TDI
Good info, thanks. So if I understand it correctly, you retain the DMF but use the RS4 disc and machine the PP surface only, and that's all it took? Brilliant idea!
 

devon1996

Well-known member
Joined
May 7, 2020
Location
Denver
TDI
08 A4 tdi swap
Good info, thanks. So if I understand it correctly, you retain the DMF but use the RS4 disc and machine the PP surface only, and that's all it took? Brilliant idea!
Yup you keep the 2.0t DMF and just machine the RS4 PP friction surface.
 

arazvan2002

Veteran Member
Joined
Sep 28, 2010
Location
Romania
TDI
Audi A4 B6 1.9TDI AVF quattro
Is the friction part thick enough so you can machine 4mm? Which RS4 clutch, B5 or B7? It is strange that you need to do tricks for pilot bearing. BHW 's brother BGW is used in Europe with manual gearbox. Engine was from automatic gearbox?
 

devon1996

Well-known member
Joined
May 7, 2020
Location
Denver
TDI
08 A4 tdi swap
Is the friction part thick enough so you can machine 4mm? Which RS4 clutch, B5 or B7? It is strange that you need to do tricks for pilot bearing. BHW 's brother BGW is used in Europe with manual gearbox. Engine was from automatic gearbox?
Yeah the bhw only came with the automatic so it has the shorter crank snout. The friction surface is super thick 4mm isnt much of it. B7 RS4
 

yahmon

Veteran Member
Joined
Dec 27, 2012
Location
canada
TDI
04 passat tdi 6spd stage2 webasto TC3 , 04 passatW8 6 spd, 10 Jetta TDI 6spd stage 1
In the process of swapping my a4 to bhw I figured out a lot of stuff that would be useful for other people doing manual swaps on the bhw.

First off is the pilot bearing. The snout of the bhw crank is shorter and with a 240mm clutch and 02x spacer the pilot bearing doesn't really reach the input shaft. I've seen adapters and also people putting the needle bearing in halfway. My solution was a oilite bronze pilot bushing. It's from a chevy 2.8 part number is PB652HD. Works perfectly and sticks out far enough for good engagement of the input shaft. I have no issues getting into gear.

Flywheel and clutch. I used the stock 2.0t DMF. The 2.0t clutch wasn't sufficient for the diesel torque so I had to figure out a new solution. The RS4 clutch is the go-to upgrade for these cars but it requires a special flywheel. I didn't want to spend the money on the flywheel so I figured out what the RS4 clutch needs to work. The key is to take 4 mm off of the surface of the pressure plate. It cost me $120 to get the PP machined to the right height. I tried to shim the plate originally but it hits the case so you have to machine it. The clutch kit it's self was $100 used with 3k miles. The car is turned up to maximum torque and I haven't even gotten the slightest indication of slippage and the engagement is smooth and light.

Starter wise I used the 2.0t gas starter. It isn't great for when it's really cold because it turns over slower than I'd like but it always starts.

Gear ratios on the gas 02x are sufficient for the bhw. I hunted down a HCK 6th gear for highway cruising. It has a .575 ratio and was $460 from Europe. I haven't installed it yet but it will yield 2400 rpm at 85 mph vs 3000 rpm now. Mileage is good still with 36-38 mpg on winter fuel with quattro and snow tires.

I used the factory thick spacer plate from the 2.0t.

And there you have it.
Crank pilot hole extension
 

adamss24

Veteran Member
Joined
Nov 2, 2005
Location
Great Britain
TDI
audi a4 2.5 tdi 98 quatrro 6speed
I remember seeing a bushing like this on a v6 tdi block with auto gearbox strapped to it, it was removed otherwise the gearbox wouldn't work as there is no support for the manual gearbox dual mass flywheel... I had to chisel it out as it was not needed !
 

Koehn

Well-known member
Joined
Oct 25, 2018
Location
Vancouver, BC
TDI
2005 A4 Avant Quattro 6-Speed (AVF)
This is good info, thank you for sharing! I've been in the process of finding my next clutch for a while and I just haven't settled on anything yet. My current top choice is TTVR's 1.8T B7 RS4 single mass flywheel. It would be interesting to know what the torque limits are for this setup.

I'm surprised the pressure plate has enough material where 4mm can be removed. For anyone that chooses to go this route, was the machining work ~4mm or was it 4.00mm exactly?

Also, was the 2.0T thick spacer required to keep the pressure plate from hitting the bell housing or did you just use it because you had it? I've got my 02X bolted straight to the AVF block with no spacer and I'm running the OEM 240mm clutch with zero issues.

As for starters, it might be worth looking into how the BHW, AWX, and 2.0T starters compare. Or even the BPW units from the B7's. It's my understanding that all of them except the AVF function similarly (I could definitely be wrong on that though).
 

JDM_dieselwagon

Active member
Joined
Dec 21, 2019
Location
Alberta
TDI
2003 Jetta Wagon ALH, 2006 Audi A4 BHW swap in progress, 2002 Ram Cummins
So I'm mid B7 A4/BHW swap and I ran into a snag on this topic. I bought a DKM 228MM single mass clutch that's make for a vw tdi to Audi transmission. I removed the 5.5mm spacer that the 2.0t-02x used as I was instructed and everything seemed to fit good. When I tested pushing the pedal it "bottomed out" I little over half way to the floor. I couldn't test to see if it was fully disengaging the clutch because the car is up on jack stands. According to my measurements the slave cylinder only has 8mm of travel to where it maxes out extension like this, a nd that's without the spacer which would make it 2.5mm. I'm not sure if it was bottoming out the fingers or "topping out" the slave cylinder, but the pedal came to a hard stop.
 
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