Today I shall be discussing gearbox codes and how to determine your code and thus identify your gearbox. Knowing what type of gearbox you have in your van is extremely important in terms of both buying parts and also in determining what ratios you have especially in regards to doing engine upgrades and the revving of your engine. If you own a VW Syncro this is especially important as the front diff and gearbox must have matching final drives otherwise severe damage will result when connected.

Types of  VW T3/ T25 gearboxes

VW T3/T25 gearboxes come in a variety of flavours ranging from gearboxes designed for early 1600cc and 2-litre aircooled engines to 1.6 litre and 1.7 litre normally aspirated diesel engines and 1.6 litre turbo diesel up to the later 1.9  and 2.1 litre water-cooled petrol engines and Syncro models both 14″ and 16″.  Depending on their application whether it be commercial or passenger type and engine type the gearboxes have different ratios some being low revving and others high revving. The boxes also came in either as a 4-speed or 5-speed. Some boxes even came with limited-slip differentials and in the case of Syncro gearboxes and front differentials, there was an option for a locking differential a decoupler, and even a Power Take Off.

Often gearboxes have been changed during the life of the van so your gearbox may not even be the original one that it left the factory with. With engine conversions often the box that is mated to the engine may not have been suitable being either too low or high geared resulting in poor fuel economy and performance.

To identify your gearbox you will need to find the code, as shown in the picture below. The gearbox code is the bottom of the gearbox and on the left side between the ribs and the gear carrier, it will usually consist of a number followed by a letter or two or three letters followed by a series of numbers. The code is the number and letter or the letters, the numbers signify the date of manufacture. Often it is very hard to decipher the code and numbers due to corrosion to see them properly. It is often necessary to give the area a good clean with a wire brush and cleaner. You can also rub some Tippex over the area can also highlight the letters and numbers for easy reading.

Quick Example

The second picture below show a code off a customer’s box. Thus the gearbox code is an ABD which is a four speed petrol  box 091/1 this was available between August 1984 till July 1987. The numbers following the code show the build date so from these we can see  it was built on the 23/01/1986.

VW Gerabox Codes
Finding your VW Gearbox Code

More Info

Now once we have the gearbox code we can establish which final drive and gears it has. To do this you can use the below table of VW gearbox codes (primarily those that apply to VW Vans & Buses). We make every effort to keep the table accurate and up to date but it is only meant to be used as a guide as there may be some errors from time to time. Feel free to report any errors that you might spot.

Common VW Van Gearbox Codes

Toggle between the options below:

VW Gearbox Color Code LegendGreen = Low Revving Gearbox <<< >>>> Red = High Revving Gearbox
Gearbox Usage:Gear Ratios:RPM @ mph in top gear with 185/80 R14 tyres (651mm dia):
Gearbox codesNo of Gears:Syncro?Disp.:(litres)Fuel:Power:(BHP)Date:G12345RFinal Drive:50607080
VW T3 4 speed gearboxes
DH4N1.6D50-31.7.823.782.061.230.825.432922350640914675
DK4N2P70-31.7.823.782.061.230.854.572549305935694079
DM4N1.6D50-31.7.823.782.061.260.855.433029363542404846
DS4N1.6D50-31.7.823.782.061.260.855.433029363542404846
DT4NP60-7.843.782.061.260.854.572549305935694079
DU4NP78 / 82-7.843.782.061.260.854.862711325337954338
DY4N1.6D10.82 –3.782.061.260.855.833252390245535203
DZ4N-31.7.823.782.061.23
2D4N-31.7.823.782.06123
4D4NP60-7.843.782.061.260.854.572549305935694079
4W4N.3.782.061.23
5D4NP76 / 82-7.843.782.061.260.854.862711325337954338
6D4N1.6D10.82 –3.782.061.260.855.863269392345765230
ABB4NP608.84 –3.782.061.230.854.572549305935694079
ABD4NP788.84 –3.782.061.230.854.832694323337724311
ABE4NP8.84 –3.782.061.230.854.832694323337724311
ABF4NP61 / 788.84 –3.782.061.234.83
ABH4N1.6TD1.85 –3.782.061.230.785.432779333538914447
ABS4N1.6TD.3.782.061.230.785.432779333538914447
ABW4ND.3.782.061.23
ACP4N1.6D3.84 –3.782.061,260.855.833252390245535203
ACR4N1.6D3.84 –3.782.061.260.855.833252390245535203
ACW4NP(SA)95 / 1122.85 –3.782.061.260.854.832694323337724311
ALD4N1.7D23.6.86 –3.782.061.230.785.52815337839414505
AOJ4N1.8?P(SA).3.782.061.230.854.832694323337724311
APF4N1.7D30.6.87 – 31.7.893.782.061.230.855.53068368242954909
VW T3 Gearboxes 5 speed
3H5N1.6D-1.854.112.331.481.020.824.832599311936394159
3P5N1.9P76 / 9012.83 –4.112.331.481.020.824.862615313836614184
8F5NP6012.83 –4.112.331.481.020.824.862615313836614184
8H5NP6012.83 –4.112.331.481.020.824.862615313836614184
8K5N1.6D12.83 –4.112.331.481.020.825.432922350640914675
8L5N1.6D12.83 –4.112.331.481.020.825.432922350640914675
8P5N.4.112.331.481.02
9D5N1.6D-11.834.112.331.481.020.785.432779333538914447
AAP5NP95 / 112.4.112.331.481.020.824.572459295134433935
AAR5NP112.4.112.331.481.020.824.572459295134433935
AAS5N1.6TD.4.112.331.481.020.824.832599311936394159
ABK5NP60– 16.7.894.112.331.481.020.824.832599311936394159
ABL5NP608.84 – 16.7.894.112.331.481.020.824.832599311936394159
ABM5NP73 / 78 / 908.84 –4.112.331.481.020.824.832599311936394159
ABN5NP73 / 78 / 908.84 –4.112.331.481.020.824.832599311936394159
ABP5N1.6, 1.7D8.84 –4.112.331.481.020.825.52960355241444736
ABR5N1.6, 1.7D8.84 –4.112.331.481.020.825.52960355241444736
AFJ5N2.5, 2.6P(SA).4.112.331.481.020.824.832599311936394159
AGT5NP87 / 95.4.112.331.481.020.824.832599311936394159
ASL5NP88 / 93 / 95.4.112.131.481.020.854.572549305935694079
ASM5NP60 / 7817.7.89 –4.112.131.481.020.85
ASN5N1.7D17.7.89 –4.112.131.481.020.825.52960355241444736
ASP5N1.7D17.7.89 –4.112.131.481.020.825.52960355241444736
ASR5N1.6TD17.7.89 –4.112.131.481.020.824.832599311936394159
ASS5N1.6TD17.7.89 –4.112.131.481.020.824.832599311936394159
DV5NP60-11.834,112.331.481.020.784.862488298534833980
DW5NP78-11.834,112.331.481.020.784.862488298534833980
DX5N1.6D-11.834,112,331.481.020.785.432779333538914447
AST5NP95.4.112.131.481.020.854.572549305935694079
VW T3 Syncro Gearboxes
AHF4+GY1.6TD5.3.86 – 31.8.896.033.782.061.230.786.035.432779333538914447
AKE4+GY2.1P1.1.87 – 31.8.896.033.782.061.230.856.034.572549305935694079
AKG4+GY2.1P10.11.86 – 31.8.896.033.782.061.230.856.034.572549305935694079
AKK4+GY1.6TD1.4.89 – 31.8.896.033.782.061.230.786.035.832984358141784775
ALE4+GY2.1P1.9.89 –6.033.782.061.230.856.035.833252390245535203
ALK4+GY2.1P1.8.87 – 31.8.896.033.782.061.230.856.035.433029363542404846
AND4+GY (16″)1.6TD1.1.88 – 31.8.896.033.782.061.230.856.036.173442413048185507
AVF4+GY1.6TD1.9.89 –6.033.781.881.236.035.83
AVH4+GYP1.9.89 –6.033.781.881.230.856.035.433029363542404846
AVJ4+GY1.6P1.9.89 –6.033.781.881.236.035.43
AVK4+GY1.6P1.9.89 –6.033.781.881.230.786.035.432779333538914447
AVL4+GY1.9, 2.1P1.9.89 –6.033.781.881.236.035.43
AVM4+GY1.9, 2.1P1.9.89 –6.033.781.881.236.035.83
AVN4+GY1.9, 2.1P1.9.89 –6.033.781.881.230.856.034.862711325337954338
AVR4+GY2.1P1.9.89 –6.033.781.881.230.856.035.833252390245535203
AVS4+GY1.6TD1.9.89 –6.033.781.881.230.786.035.832984358141784775
AVU4+GY (16″)1.6TD1.9.89 –6.033.781.881.230.856.036.173442413048185507
AVV4+GY1.9, 2.1P1.9.89 –6.033.781.881.230.856.034.862711325337954338
VW Gearbox Color Code LegendGreen = Low Revving Gearbox <<< >>>> Red = High Revving Gearbox As you can see here are some examples of how you can change a high revving gearbox to a much more lower revving one in the table below:
Gearbox Usage:Gear Ratios:RPM @ mph in top gear with 185/80 R14 tyres (651mm dia):
Gearbox codesNo of Gears:Syncro?Disp.:(litres)Fuel:Power:(BHP)Date:G12345RFinal Drive:50607080
Some examples of modified boxes with different gearing
DH4N1.6D50-31.7.823.782.061.230.825.432922350640914675
Same gearbox with a 4.14 Crown and Pinion
DH4N1.6D10.82 –3.782.061.260.824.142200270031503600
4D4NP60-7.843.782.061.260.854.572549305935694079
Same gearbox with a longer 3rd and 4th gear
4D4NP60-7.843.782.061.020.784.572350280032703750
3H5N1.6D-1.854.112.331.481.020.824.832599311936394159
Same gearbox 4.14 crown and pinion
3H5N1.6D-1.854.112.331.481.020.784.142150255030003400
Syncro AHF
AHF4+GY1.6TD5.3.86 – 31.8.896.033.782.061.230.786.035.432779333538914447
Syncro AHF converted to TDI with longer 3rd and 4th and bigger tyres 215/75/15
AHF4+GY1.6TD5.3.86 – 31.8.896.033.782.061.090.76.035.432300277032503700

In the OEM Gearbox toggle option just above, you can find your VW Gearbox code and see what type of box you have, which gear ratios it has, and which engine it was originally mated to. Also, it will show you which revs it should have at a given speed.

For those of you wishing to convert your van this shows which boxes are more suitable for engine conversions. Of course, if you are unhappy with your gearbox it is always possible to change the gearing. This can be done in a number of ways

  1. changing your Crown and Pinion ratio this will lengthen all the gears in your gearbox

Or

  1. Stock Gears either by changing the highest gear usually a 0.85 to either a 0.82 or 0.78 gears which are found in diesel or 5 speed gearboxes

Or

  1. Custom Gears these are also usually Heavy Duty gears and are available in a range of ratios for both 3rd and 4th gears (4th and 5th in a 5-speed) so you can tune your box very accurately to your tyre size and engine choice.

As you can see here are some examples of how you can change a high revving gearbox to a much more lower revving one in the “Modified” toggle option above.

Of course in order to change the gearing on a gearbox it is necessary to strip and rebuild it. Our rebuild services can be found here for all types of boxes.

If you have any questions just drop me an email to vwvantopia@gmail.com and I will be more than happy to go through the details with you,

Thanks, 

Paul