Bluemotion MZN gearbox, an alternative...

Again, thank you Gentlemen for the kind words!
This club and forum is an inspiration to A2 owners.
It's a privilege to have met Tom here in Holland, indeed in times of freedom...... Hope these times will return soon and that everyone here will stay healthy, strong and/or will survive this awful virus.

To be back on topic @sco, the cut away piece on the gearbox was, err, lets say "generous".....
I prepared the box from information found regarding other bluemotion boxes on the internet, that are altered the same way.
Now, if I did it again I would leave more material present.
A case of being to eager and not doing a dedicated research, mea culpa.
Although it seems very fragile, I can say that in my opinion the casing/bung is still strong enough, and the bracket on top is bolted together with 3ea M10 bolts, which gives strength to the whole assembly too.

This a picture of the aft side;
IMG_20200408_101551.jpg

If it will not hold it will be a shame, and I will let you all know, no holding back from my side if it goes ugly!
But I hope it's staying in one piece.

Menno.
 
I was a little worried as per Simon
So I drilled a 10mm hole and sawed into the sides of the hole this leaving a radius instead of a sharp corner. Likely not needed but nearly 40 years in the aircraft industry as taught me to avoid sharp corners like the covid19 virus

Paul


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depronman said:
I was a little worried as per Simon
So I drilled a 10mm hole and sawed into the sides of the hole this leaving a radius instead of a sharp corner. Likely not needed but nearly 40 years in the aircraft industry as taught me to avoid sharp corners like the covid19 virus

Paul


Sent from my iPhone using Tapatalk
Click to expand...

Sharp...... Good thinking, didn't crossed my mind.
As said, hope mine's holding on, it seems sturdy enough.
Well, can't undo it anymore, but a lesson learned again!
 
Now done about 20 miles on my JDD box and I have to say it’s a great improvement
The gearing is tall but not overly tall
My remapped amf happily changes up and pulls well at the following speeds on level ground
2nd gear 10 to 15mph
3rd gear 30 mph
4th gear 40 mph
5th gear 50 to 55 mph but if you want to accelerate at a reasonable pace then 60 mph

60 mph is 1800 rpm
70 mph is 2050 rpm

God knows what this does to the top speed I think the 108 mph will be well exceeded not that I will be trying this in the uk

I’m expecting cabin noise at 70 mph will be greatly reduced even over the long 5th gear set up that I had before the jdd

An added advantage is the gear change is massively improved, granted I did some work on removing any slop in the gear change linkages but the jdd box appears to have a slightly shorter shift gate and just feels more like a petrol A2 gearbox than the original tdi box

Level road at 60 mph in 5th with a nearly warmed up engine was reporting 92 mpg in cruise control over about a mile so I would say it’s all looking rather positive so far
Cheers. Paul


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For any one reading this ,which is great by the way , I have a ALT 90 gear box sat on the floor of the shed , which I will have to send to the scrap yard in the next couple of months .it’s listed on the market place , but would be open to offers ...
GRJ is the code I believe

the box was removed to make way for the MYP Box which works very well , in part thanks for the remap
The fancy DIS fitted by @timmus shows the engine is putting out around 280nm so a little over the rating of the box at 250nm , but 20k miles later it holding up fine

I must say , love the information this group can draw on , and the shared knowledge which has been built up over many year !
 
Good morning from Spain.

Thank you very much for the information, I think it is a very good solution for our cars (especially in Spain, which has a lot of mountains).

I wanted to ask you if you know the differences between an MZN box (which seems ideal to me because of gear ratio) and the ones you comment on MAL, MNY and MZK codes.

In Spain these types of spare parts are expensive and want to know diferences between them to search a cheap one. It is for a BHC with a remap.

Thanks!


Menno said:
….

Enter a MZN (or MAL, MNY, MZK) gearbox. In my opinion it sits between a GRJ and a JDD gearbox in terms of gear ratios.
They're also fairly cheap and plenty to be found in comparison with the above other options.
I've done some research on Google (don't forget to put your b*llSh*t filter on....?) and found that some people did install this gearbox successfully on an A2.
….


Aloha,
Menno.
Click to expand...
 
Away with the fairys said:
...which I will have to send to the scrap yard in the next couple of months
Click to expand...
GRJ gearboxes are really quite rare. It'd be a shame for it to go to the scrappy. If you've no takers, please donate it to WOM or me, as we'll eventually find a good home for it. My sister's BHC-engined A2 will need a clutch change in the coming years, and she'd probably benefit from having the fractionally longer gearing of the TDI90.

Cheers,

Tom
 
ibizagti said:
Good morning from Spain.

Thank you very much for the information, I think it is a very good solution for our cars (especially in Spain, which has a lot of mountains).

I wanted to ask you if you know the differences between an MZN box (which seems ideal to me because of gear ratio) and the ones you comment on MAL, MNY and MZK codes.

In Spain these types of spare parts are expensive and want to know diferences between them to search a cheap one. It is for a BHC with Depronman remap.

Thanks!
Click to expand...


Ola Espagna, que tal?!

Look at the last row, they're equal.

IMG_20200423_095928.jpg

Hasta luego.
 
OK, if @Menno doesn't mind me widening the scope of his thread somewhat just for a momnet, could we sum up gearbox modification pathways here? It's very confusing looking through the multitude of threads on the subject of various swaps!

It seems to me that the following options are open to those who are considering changing their gearing (I assume here that I would get a specialist to do the work as I would):

1) For the ultimate in flexibility: Go the MYP 6 speed speed swap route: It's going to cost as follows - assuming you are not planning to DIY:
  • £3-400 for the box itself (ebay prices),
  • £425 for labour at one of the specialists, including making up the required cable brackets, if you have a TDI90 (I got a quote) - It would be higher if you have a TDI75 due to the latter's single mass flywheel setup - £500-550ish?
Total budget to plan for: £725-825, plus potentially a new clutch / DMF while you're there (£350ish for a TDI90, for reference)

2) If you don't want to go all-out; and your goal is to have a nice "spread" of gears that are fairly well spaced out from each other - then you can fit either a JDD 5 speed gearbox (if you will mostly be driving in flat areas on major trunk routes and want the maximum possible gearing for best possible fuel consumption and lowest possible cabin noise) or else a MZN 5 speed that will mostly acheive the same goal with better flexibility / "driveability" through the gears. Costs:
  • £225-325 for the box itself,
  • £350ish for labour (this is my estimate, would love someone to chime in with an actual figure they have experienced). To convert a TDI90 would cost more because of the DMF, so no point in going for this option.
Total budget to plan for: £575-675, plus potentially a new clutch

3) If you want a slightly cheaper upgrade to achieve the same 5th gear cruising ability as the JDD as above and you're willing to stomach a loss of flexibility caused by the large gap from 4th, then, install a longer 5th gear into the box you have. This can be done with the gearbox in-situ and hence attracts lower labour costs (but it strikes me that the cost overall is really not all that much lower):

Total budget to plan for: £270 from @depronman from one of his threads I read (was two years old so you may charge a little more now if you're still doing this service), again with a new clutch potentially being needed and hence extra.


I'd love for others to chime in here to correct my asssumptions: As it is then it strikes me that if you're paying a specialist - and unless you're a strong DIY-er, you would be - here are my personal conclusions based on what I've read on this wonderful site:
  • If you have a TDI90, unless you really would miss the extra 150 quid, it seems a clear no-brainer to go straight to the MYP six speed;
  • If you have a TDI75 that hasn't been remapped and you don't want to get this done at the same time - go for the MZN;
  • If you have a TDI75 that has been remapped (or of course plan to get this done at the same time); AND
    • You'll be driving on a mix of minor and major roads in hilly areas as well as major / fast routes AND, get the MZN;
    • You'll be almost exclusively in flatter areas driving on major / fast routes and want the best possible improvement in cabin noise levels & fuel consumption, then you have the following choices:
      1. If budget is less of a concern, go for the six speed (MYP or via your own box modified to accept the extra gear);
      2. If you have some budget to play with but equally are happy to trade a little upper gear flexibility (which you may or may not miss anyway), get the JDD;
      3. Else, if you're on a tight budget then go for the long 5th option in your current box.
Have I got this about right, or are my assumptions around, for example, how easy it is to DIY install the longer 5th gear to the standard box incorrect?
 
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Oh noooooo! I'm only driving flat surface, and UNDER sea-level....... Should have taken a JDD... ;), just kidding.

@dj_efk , Go ahead and yes, ask and widen the scope!
The more input on this subject, the better...... It doesn't get more clear (maybe), but you can take what you like or sounds plausible and think about it.

About cost; at the breakers here in Holland, prices for a used MZN or MNY start at €150. JDD'S are higher priced over here.

Seals and new gearbox oil and sleeve for clutch bearing are about €25—€30 on the internet.
I strongly recommend to replace them before you install the box.

Also, the clutch, if you don't have a history present on this part, make sure you have a new one ready to fit.
I had a fairly new one in my car (receipt of former owner), but I still bought a new set to keep the work flow going if it was required.
All DIY by the way.
 
dj_efk said:
3) If you want a slightly cheaper upgrade to achieve the same 5th gear cruising ability as the JDD as above and you're willing to stomach a loss of flexibility caused by the large gap from 4th, then, install a longer 5th gear into the box you have.
Click to expand...
A slight correction...
The longer 5th is equivalent to the 5th gear in the MZN 'box (circa 2270rpm at 70mph). The JDD's 5th gear is equivalent to the 6th gear in the MYP 'box (circa 2050rpm at 70mph).

Broadly speaking, your summary is correct. You've got three options, and each option has a few sub-options....
  1. Get 6 gears.
    • Fit an MYP, PTW, PTU, etc, gearbox.
    • Add a 6th gear to the existing 'box (this, in my opinion, is truly 'the ultimate').
  2. Install an alternative 5-speed gearbox with a larger but even spread of gears.
    • GRJ from the TDI90 lengthens just a little.
    • MZN lengthens to a medium extent.
    • JDD lengthens to the max.
  3. Keep the car's original 'box and just lengthen the 5th gear.
    • 0.681 ratio lengthens just a little.
    • 0.659 ratio lengthens to a medium extent (the default choice, and what we mean by "the longer 5th")
    • 0.622 ratio lengthens to the max.
Cheers,

Tom
 
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Tom, what makes you favour modifying the original gearbox with the additional gear vs. Fitting the MYP?

When I asked one of the well-known A2 specialist garages, they said the following: “To be honest, based on the substantial cost and the inferior quality of the 6 speed conversion using the A2’s own box we wouldn’t recommend this route when the MYP option is on offer (it would work out more expensive than the MYP box with little/no benefit.”
 
It's a combination of things, some of which apply universally, and others are specific to the precise model of A2 you're looking to upgrade.

The MYP gearbox was designed for use in cars with a dual-mass flywheel and without a speedo drive in the gearbox. The only A2 that matches this description is the TDI90. So, if you're upgrading a TDI90, it's fairly straightforward. The only further considerations are starter motor compatibility and the custom brackets that are needed to mount the shift cables.

If you've got a TDI75 with a single-mass flywheel and without a speedo drive in the gearbox, then you have one additional problem to solve: the MYP's bell-housing is too deep. This can be solved by two methods; make a hybrid gearbox, using the bell-housing from your existing gearbox, or skim the MYP's bell-housing such that its of the correct depth for a single-mass flywheel. More money needed.

If you've got a TDI75 with a single-mass flywheel and with a speedo drive in the gearbox, then you have two additional problems to solve: the MYP's bell-housing is too deep, and its differential casing can't accommodate a speedo drive. Making a more complex hybrid of your existing gearbox and the MYP gearbox is the only option. This gets quite involved and costs really start to mount up.

The MYP's shift tower has a shorter throw than the standard gearbox, but is no less notchy. As such, changing gear is like pushing a door open from its halfway point rather than at the edge. I consider this to be a downgrade compared to the original gearbox, though others don't seem to mind.

I reject the suggestion that the 6-speed conversion kit is of inferior quality. On the contrary, many of the parts that are supplied with the kit are genuine VAG parts. The bits that are custom CNC machined are of excellent quality. They were originally designed for converting VW T4 and T5 vans, so are heavy duty.
The conversion kit arranges the gears inside the gearbox such that 6th gear (the one that presents the greatest load) is evenly supported by the three shaft bearings. The MYP gearbox has 6th gear at the very end of the shafts, as far from the torque input as possible. The conversion kit's 6th gear is marginally longer than that of the MYP gearbox, meaning a further reduction in revs at cruising speed. There are no compatibility considerations with regards to starter motors. No mounting points need to be sawn off. No custom bracketry needs to be fabricated to support the shift cables. The gear-change action within the cab is retained. It is, to my mind, the most elegant, factory-standard way of getting 6 gears. Yes, it's expensive, but the MYP gearbox is only a cheap option if you have a TDI90. If you have a TDI75 with a speedo drive (like mine), so much hybridisation/modification work is required that it's probably no less expensive than the conversion kit.

Of course, the conversion kit is best fitted to a gearbox that you trust.

Cheers,

Tom
 
@timmus, good write up Tom!
If I was confident enough to keep my AMF forever, I would seriously consider the addition of a 6th gear to the EWQ.

Why don't I now? Well, environment and government decisions will dictate if my AMF will be allowed in the future as a daily driver (in the Netherlands and/or Europe). So I'm willing to make improvements (hence the MZN) on the car, but at limited costs...... I'm sorry, I'm afraid to have to let it go someday in the future because of rules which tell me to.

But hej, this is off topic........ Again Tom, thanks for making things understandable and clear!

Cheers, Menno.
 
dj_efk said:
OK, if @Menno doesn't mind me widening the scope of his thread somewhat just for a momnet, could we sum up gearbox modification pathways here? It's very confusing looking through the multitude of threads on the subject of various swaps!

It seems to me that the following options are open to those who are considering changing their gearing (I assume here that I would get a specialist to do the work as I would):

1) For the ultimate in flexibility: Go the MYP 6 speed speed swap route: It's going to cost as follows - assuming you are not planning to DIY:
  • £3-400 for the box itself (ebay prices),
  • £425 for labour at one of the specialists, including making up the required cable brackets, if you have a TDI90 (I got a quote) - It would be higher if you have a TDI75 due to the latter's single mass flywheel setup - £500-550ish?
Total budget to plan for: £725-825, plus potentially a new clutch / DMF while you're there (£350ish for a TDI90, for reference)

2) If you don't want to go all-out; and your goal is to have a nice "spread" of gears that are fairly well spaced out from each other - then you can fit either a JDD 5 speed gearbox (if you will mostly be driving in flat areas on major trunk routes and want the maximum possible gearing for best possible fuel consumption and lowest possible cabin noise) or else a MZN 5 speed that will mostly acheive the same goal with better flexibility / "driveability" through the gears. Costs:
  • £225-325 for the box itself,
  • £350ish for labour (this is my estimate, would love someone to chime in with an actual figure they have experienced). To convert a TDI90 would cost more because of the DMF, so no point in going for this option.
Total budget to plan for: £575-675, plus potentially a new clutch

3) If you want a slightly cheaper upgrade to achieve the same 5th gear cruising ability as the JDD as above and you're willing to stomach a loss of flexibility caused by the large gap from 4th, then, install a longer 5th gear into the box you have. This can be done with the gearbox in-situ and hence attracts lower labour costs (but it strikes me that the cost overall is really not all that much lower):

Total budget to plan for: £270 from @depronman from one of his threads I read (was two years old so you may charge a little more now if you're still doing this service), again with a new clutch potentially being needed and hence extra.


I'd love for others to chime in here to correct my asssumptions: As it is then it strikes me that if you're paying a specialist - and unless you're a strong DIY-er and comfortable playing with gearbox innards, you would be - here are my personal conclusions based on what I've read on this wonderful site:
  • If you have a TDI90, unless you really would miss the extra 150 quid, it seems a clear no-brainer to go straight to the MYP six speed;
  • If you have a TDI75 that hasn't been remapped and you don't want to get this done at the same time - go for the MZN;
  • If you have a TDI75 that has been remapped (or of course plan to get this done at the same time); AND
    • You'll be driving on a mix of minor and major roads in hilly areas as well as major / fast routes AND, get the MZN;
    • You'll be almost exclusively in flatter areas driving on major / fast routes and want the best possible improvement in cabin noise levels and fuel consumption, get the JDD ideally - Else, if you're on a tight budget then go for the long 5th option in your current box.
Have I got this about right, or are my assumptions around, for example, how easy it is to DIY install the longer 5th gear to the standard box incorrect?
Click to expand...

Re option 3. Long 5th gear
Your cost as are still roughly correct
I would say it is a very good option if firstly your existing gearbox is in good order ie no crunching from 4th to 3rd and the tower bearings are in good order and
Secondly if the clutch is in good order because it’s the only one of your options which does not involve removing the gearbox so there is no access to the clutch that would naturally be there if changing the gearbox
The massive advantage to the long 5th is it is done without removing the gearbox hence the labour is very much reduced compared to a different gearbox and the associated labour involved in removing the old box and fitting the new one

Yes there is a gap between 4th and 5th which you need to adapt you driving style too
Even in hilly areas it’s ok as with the std gearbox 5th is not a gear that would be in use hilly areas anyway (when climbing hills)

Personally I only changed to the jdd because I got one at a very cheap price and of known origin and low miles
What I will say is so far it’s a decent upgrade as the gap to manage in gears is no longer present
You are basically using 1 to 4 up to 55mph so consider 5th on the jdd as a overdrive gear similar to what vag did in the mid 80’s with 4 plus E gearboxes
You don’t loose much other than a little flexibility as the same ratios are available on the jdd 1 to 4 gears as the original box had 1 to 5 gears


I would consider NO gearing upgrades unless the engine is remapped as in std trim the little 3 potter will not pull the higher gearing
Now introduce a decent remap and you have just added 25% more power and 20% more torque but just as important you have also got the torque coming on tap at lower revs and also continuing strongly to just over 4000 rpm
Std map is useless beyond 3100rpm and under 1800rpm
Remap is good from 1500 to 4200. This is the main reason why the slight lack of flexibility on the jdd box is not felt

I think what you have to take into account is that none of the gearing upgrades will ever pay for themselves in fuel saved
Yes there is a saving but you would need to drive a VERY long way in just the higher gear to pay for the cost of the upgrade
In terms of cabin noise reduction and more relaxed cruising then you are on a winner

Would I like a 6 speed box - yes I would but can I justify a £1000 plus bill to get it - not a chance
Am I happy with the JDD box for £100 plus a new clutch that I didn’t need at £80 - yes I am
(If I was doing the job again I would not have changed the clutch just fitted a new top hat at £12 and a new release bearing £15


Both options all done using DIY fitting

Cheers. Paul


Sent from my iPhone using Tapatalk
 
timmus said:
GRJ gearboxes are really quite rare. It'd be a shame for it to go to the scrappy. If you've no takers, please donate it to WOM or me, as we'll eventually find a good home for it. My sister's BHC-engined A2 will need a clutch change in the coming years, and she'd probably benefit from having the fractionally longer gearing of the TDI90.

Cheers,

Tom
Click to expand...
Hi Tom , noted and it will not be going to the scrappy ! , it does however need to move , much like all of us at this time ...l.
 
@depronman
depronman said:
Re option 3. Long 5th gear
Your cost as are still roughly correct
I would say it is a very good option if firstly your existing gearbox is in good order ie no crunching from 4th to 3rd and the tower bearings are in good order and
Secondly if the clutch is in good order because it’s the only one of your options which does not involve removing the gearbox so there is no access to the clutch that would naturally be there if changing the gearbox
The massive advantage to the long 5th is it is done without removing the gearbox hence the labour is very much reduced compared to a different gearbox and the associated labour involved in removing the old box and fitting the new one

Yes there is a gap between 4th and 5th which you need to adapt you driving style too
Even in hilly areas it’s ok as with the std gearbox 5th is not a gear that would be in use hilly areas anyway (when climbing hills)

Personally I only changed to the jdd because I got one at a very cheap price and of known origin and low miles
What I will say is so far it’s a decent upgrade as the gap to manage in gears is no longer present
You are basically using 1 to 4 up to 55mph so consider 5th on the jdd as a overdrive gear similar to what vag did in the mid 80’s with 4 plus E gearboxes
You don’t loose much other than a little flexibility as the same ratios are available on the jdd 1 to 4 gears as the original box had 1 to 5 gears


I would consider NO gearing upgrades unless the engine is remapped as in std trim the little 3 potter will not pull the higher gearing
Now introduce a decent remap and you have just added 25% more power and 20% more torque but just as important you have also got the torque coming on tap at lower revs and also continuing strongly to just over 4000 rpm
Std map is useless beyond 3100rpm and under 1800rpm
Remap is good from 1500 to 4200. This is the main reason why the slight lack of flexibility on the jdd box is not felt

I think what you have to take into account is that none of the gearing upgrades will ever pay for themselves in fuel saved
Yes there is a saving but you would need to drive a VERY long way in just the higher gear to pay for the cost of the upgrade
In terms of cabin noise reduction and more relaxed cruising then you are on a winner

Would I like a 6 speed box - yes I would but can I justify a £1000 plus bill to get it - not a chance
Am I happy with the JDD box for £100 plus a new clutch that I didn’t need at £80 - yes I am
(If I was doing the job again I would not have changed the clutch just fitted a new top hat at £12 and a new release bearing £15


Both options all done using DIY fitting

Cheers. Paul


Sent from my iPhone using Tapatalk
Click to expand...

Can you comment on flexibility/ drivability in 30 and 40 mph limit areas? Looking at the in gear RPMs it seems the JDD may even be the better choice over MZN in urban areas, however the MZN could also find it's place depending on the situation - I see that the revs at:
  • around 30mph in the JDD third are pretty ideal at around 1700 RPM; versus the MZN being at just about / just under 2000RPM, so slightly less ideal;
  • around 40mph in the JDD in fourth are at / just over 1500RPM - Quite low / out of the (remapped) power band, but perhaps OK to cruise along on light throttle(?) but you'd need to change down to accelerate; versus the MZN where the revs being at 1650/1700 RPM are probably slightly more ideal?
Once again - the six speed shows itself to be superior across both these situations.

Really interesting discussion / choice here! I don't know of any other modern-ish car where there's so much space for creativity / customisation.
 
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3rd gear is very flexible and the car is happy in 3rd at 25 mph and pulls strongly from there it will tolerate 20 mph as long as you don’t want to accelerate fast but even then the revs don’t take too long to rise into the power band
3rd will equally handle 40 mph but at the unnecessarily high revs
4th at 38 mph is ok and similar to 3rd at 20 mph by 45mph it will pull strongly
By car as oss and is a 5 seater and as a spare wheel as well so is lugging around that extra weight all the time but I should point out so far there has only been me in the car due to lockdown issues
I actually think 1st and 2nd hear are better than the original box due to the longer gearing provided by the diff and you don’t appear to be revving as high in 1&2 which means that by the time you change to third the road speed is naturally around 25 to 28 mph and therefore suitable for 3rd

The strange bit is driving around at 45 to 50mph in 4th, you brain needs retrained to accept this as normal and indeed it’s the same revs that the original box would do in original 5th but the gear stick is firmly in 4th. It’s just a brain training issue that I’m sure will feel natural after a few hundred miles
The gear change on the jdd box is so sweet it’s a pleasure to change gear now
Paul


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