can you swap a hkg tiptronic for a hzr or other?

[fatty jr]

Looks like I've blown my tiptronic box my my 3.0tdi c6 ( barstool)

 

I'm Searching for replacements and can't seem to find a hkg code box.

I'm wondering if I can swap my HKG box for a hzr box provided it's the same part number???  Can't seem to find any information on the subject

[Steve Q]

Not too sure but surely it won't be the same part number if there's slight differences between the gearboxes? 

My advice would be to try eBay. 

[fatty jr]

I've tried eBay and I've only found one that is HKG code is in Europe for parts 😞

[Steve Q]

4 hours ago, fatty jr said:

I've tried eBay and I've only found one that is HKG code is in Europe for parts 😞

So annoying, I did have a look online but I too didn't find anything useful. My advice would be to speak to an Audi specialist or gearbox specialist. Sorry I can't help more

[ejenner]

did you figure this out?  I have the same problem of HKG gearboxes not being as easy to find. 

[ejenner]

In case anybody looks at this again in the future wondering whether or not you can play around with gearbox codes I have a useful update. 

I decided to take the plunge for lack of availability of the HKG transmission and replaced it with a GZV gearbox.  The GZV is actually a gearbox from the A8.  I got one from a very similar age to the one out of my A6.  

When it came to fitting I found some of the bolts on the exterior of the housing were in different places but fundamentally one was a good match to the other and all the major things were the same.  The differences were really tiny.  The gearshift selector cable was mounted differently but the A8 box had the lugs in the casting for mounting the cable.  I cleaned the threads as the lugs were unused on the A8 installation and had become dirty / corroded.  I tapped them out and then they were fine to mount the A6 selector cable.  Similar story for the offside gearbox mount... one of the 4 bolts was in a different place but existed the same on both gearboxes.  The only other thing I had to change was the cam that connects to the gear selector.  They're different between the A6 and the A8.  Held on with a roll-pin so very easy to swap. 

The main decision I had to make was about which valve body to use.  You have to keep your original gearbox control module no matter what you end up doing as the module is coded to the car.  The control module is inside the gearbox on top of the valve body.  If you fit an un-coded foreign module to your car it will limit speed to 8mph. 

I decided to use the new gearbox with the new valve body that came with the gearbox on the logic that it would be adapted to that gearbox and compatible with it.  I could see there were different coloured solenoid valves on the new v.s. the old.  I also wondered if my old valve body was faulty. 

Knowing it was possible to swap the valve body without removing the whole transmission made a big difference to my decision making as I knew I could try both of them pretty easily. 

So I swapped my original control module onto the new valve body.  Assembled everything and it wasn't good.  There was a delay and clunk going into reverse.  I didn't drive it any further than forward and back.  Looking at the solenoid colours in the manual it did seem to say there were differences in their functions.  

My logic for making the decision to use the new valve body on the basis that it would be matched to the box was faulty.  I should have prioritised matching the valve body to the control module instead.  But fear of the old valve body being broken pushed me towards using the new valve body.  

Once I swapped the old valve body back into the box everything was sweet.  Very smooth drive.  I noticed that initially it was speed flaring a bit (where the revs aren't matched to the gears) but after 30-odd miles of mixed driving I can see that has adapted itself out.  I was expecting this so was not concerned to see it on the first few miles.  The module learns what position the solenoids should be moved to to control gearchanges smoothly.  This is by design and allows you to run oils in a variety of different states of wear.  So an old oil that's become thick with wear particles will work as smoothly as new oil.  Similarly gears and clutches which have worn can continue to operate as smoothly as they did when they were new even if they're worn.  This is all taken care of by adaption and learning in the control module. 

A possible hybrid solution would be to ensure the new valve body had the correct coloured solenoids in the correct positions to match the old valve body.  They don't make them different colours for no reason and I assume using a blue solenoid instead of a white solenoid for engaging reverse gear is fundamentally wrong and this is why it didn't reverse well.  You would have to look for differences in the valve body to see if you could swap solenoids.  You might also be able to code a foreign control module to your car if you have full diagnostics operational. 

So at the end of the day... yes you can swap one box for another... even between different models of 3.0 tdi quattro.  What I did to try and make sure this would definitely work was to check very carefully the external appearance of the two different boxes looking online at the advert photo for the replacement box.  They looked identical and were from very similar years so I went for it. 

Edited March 29, 2023 by ejenner

[Steve Q]

On 3/29/2023 at 9:35 AM, ejenner said:

In case anybody looks at this again in the future wondering whether or not you can play around with gearbox codes I have a useful update. 

I decided to take the plunge for lack of availability of the HKG transmission and replaced it with a GZV gearbox.  The GZV is actually a gearbox from the A8.  I got one from a very similar age to the one out of my A6.  

When it came to fitting I found some of the bolts on the exterior of the housing were in different places but fundamentally one was a good match to the other and all the major things were the same.  The differences were really tiny.  The gearshift selector cable was mounted differently but the A8 box had the lugs in the casting for mounting the cable.  I cleaned the threads as the lugs were unused on the A8 installation and had become dirty / corroded.  I tapped them out and then they were fine to mount the A6 selector cable.  Similar story for the offside gearbox mount... one of the 4 bolts was in a different place but existed the same on both gearboxes.  The only other thing I had to change was the cam that connects to the gear selector.  They're different between the A6 and the A8.  Held on with a roll-pin so very easy to swap. 

The main decision I had to make was about which valve body to use.  You have to keep your original gearbox control module no matter what you end up doing as the module is coded to the car.  The control module is inside the gearbox on top of the valve body.  If you fit an un-coded foreign module to your car it will limit speed to 8mph. 

I decided to use the new gearbox with the new valve body that came with the gearbox on the logic that it would be adapted to that gearbox and compatible with it.  I could see there were different coloured solenoid valves on the new v.s. the old.  I also wondered if my old valve body was faulty. 

Knowing it was possible to swap the valve body without removing the whole transmission made a big difference to my decision making as I knew I could try both of them pretty easily. 

So I swapped my original control module onto the new valve body.  Assembled everything and it wasn't good.  There was a delay and clunk going into reverse.  I didn't drive it any further than forward and back.  Looking at the solenoid colours in the manual it did seem to say there were differences in their functions.  

My logic for making the decision to use the new valve body on the basis that it would be matched to the box was faulty.  I should have prioritised matching the valve body to the control module instead.  But fear of the old valve body being broken pushed me towards using the new valve body.  

Once I swapped the old valve body back into the box everything was sweet.  Very smooth drive.  I noticed that initially it was speed flaring a bit (where the revs aren't matched to the gears) but after 30-odd miles of mixed driving I can see that has adapted itself out.  I was expecting this so was not concerned to see it on the first few miles.  The module learns what position the solenoids should be moved to to control gearchanges smoothly.  This is by design and allows you to run oils in a variety of different states of wear.  So an old oil that's become thick with wear particles will work as smoothly as new oil.  Similarly gears and clutches which have worn can continue to operate as smoothly as they did when they were new even if they're worn.  This is all taken care of by adaption and learning in the control module. 

A possible hybrid solution would be to ensure the new valve body had the correct coloured solenoids in the correct positions to match the old valve body.  They don't make them different colours for no reason and I assume using a blue solenoid instead of a white solenoid for engaging reverse gear is fundamentally wrong and this is why it didn't reverse well.  You would have to look for differences in the valve body to see if you could swap solenoids.  You might also be able to code a foreign control module to your car if you have full diagnostics operational. 

So at the end of the day... yes you can swap one box for another... even between different models of 3.0 tdi quattro.  What I did to try and make sure this would definitely work was to check very carefully the external appearance of the two different boxes looking online at the advert photo for the replacement box.  They looked identical and were from very similar years so I went for it. 

Thanks for that very useful update 😊 glad you got sorted 👍