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.

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:

OEM Gearbox

Green = Low Revving Gearbox <<< >>>> Red = High Revving Gearbox

		Gearbox Usage:					Gear Ratios:										RPM @ mph in top gear with 185/80 R14 tyres (651mm dia):
Gearbox codes	No of Gears:	Syncro?	Disp.:(litres)	Fuel:	Power:(BHP)	Date:	G	1		2	3		4	5	R	Final Drive:	50	60	70	80
VW T3 4 speed gearboxes
DH		4	N	1.6	D	50	-31.7.82	–	3.78		2.06	1.23		0.82	–		5.43	2922	3506	4091	4675
DK		4	N	2	P	70	-31.7.82	–	3.78		2.06	1.23		0.85	–		4.57	2549	3059	3569	4079
DM	4	N	1.6	D	50	-31.7.82	–	3.78		2.06	1.26		0.85	–		5.43	3029	3635	4240	4846
DS	4	N	1.6	D	50	-31.7.82	–	3.78		2.06	1.26		0.85	–		5.43	3029	3635	4240	4846
DT	4	N		P	60	-7.84	–	3.78		2.06	1.26		0.85	–		4.57	2549	3059	3569	4079
DU	4	N		P	78 / 82	-7.84	–	3.78		2.06	1.26		0.85	–		4.86	2711	3253	3795	4338
DY	4	N	1.6	D		10.82 –	–	3.78		2.06	1.26		0.85	–		5.83	3252	3902	4553	5203
DZ	4	N				-31.7.82	–	3.78		2.06	1.23			–
2D	4	N				-31.7.82	–	3.78		2.06	123			–
4D	4	N		P	60	-7.84	–	3.78		2.06	1.26		0.85	–		4.57	2549	3059	3569	4079
4W	4	N				.	–	3.78		2.06	1.23			–
5D	4	N		P	76 / 82	-7.84	–	3.78		2.06	1.26		0.85	–		4.86	2711	3253	3795	4338
6D	4	N	1.6	D		10.82 –	–	3.78		2.06	1.26		0.85	–		5.86	3269	3923	4576	5230
ABB	4	N		P	60	8.84 –	—	3.78		2.06	1.23		0.85	—		4.57	2549	3059	3569	4079
ABD	4	N		P	78	8.84 –	—	3.78		2.06	1.23		0.85	—		4.83	2694	3233	3772	4311
ABE	4	N		P		8.84 –	—	3.78		2.06	1.23		0.85	—		4.83	2694	3233	3772	4311
ABF	4	N		P	61 / 78	8.84 –	—	3.78		2.06	1.23			—		4.83
ABH	4	N	1.6	TD		1.85 –	—	3.78		2.06	1.23		0.78	—		5.43	2779	3335	3891	4447
ABS	4	N	1.6	TD		.	—	3.78		2.06	1.23		0.78	—		5.43	2779	3335	3891	4447
ABW	4	N		D		.	—	3.78		2.06	1.23			—
ACP	4	N	1.6	D		3.84 –	—	3.78		2.06	1,26		0.85	—		5.83	3252	3902	4553	5203
ACR	4	N	1.6	D		3.84 –	—	3.78		2.06	1.26		0.85	—		5.83	3252	3902	4553	5203
ACW	4	N		P(SA)	95 / 112	2.85 –	—	3.78		2.06	1.26		0.85	—		4.83	2694	3233	3772	4311
ALD	4	N	1.7	D		23.6.86 –		3.78		2.06	1.23		0.78	—		5.5	2815	3378	3941	4505
AOJ	4	N	1.8?	P(SA)		.	–	3.78		2.06	1.23		0.85	—		4.83	2694	3233	3772	4311
APF	4	N	1.7	D		30.6.87 – 31.7.89	–	3.78		2.06	1.23		0.85	—		5.5	3068	3682	4295	4909
VW T3 Gearboxes 5 speed
3H	5	N	1.6	D		-1.85	–	4.11		2.33	1.48		1.02	0.82		4.83	2599	3119	3639	4159
3P	5	N	1.9	P	76 / 90	12.83 –	–	4.11		2.33	1.48		1.02	0.82		4.86	2615	3138	3661	4184
8F	5	N		P	60	12.83 –	–	4.11		2.33	1.48		1.02	0.82		4.86	2615	3138	3661	4184
8H	5	N		P	60	12.83 –	–	4.11		2.33	1.48		1.02	0.82		4.86	2615	3138	3661	4184
8K	5	N	1.6	D		12.83 –	–	4.11		2.33	1.48		1.02	0.82		5.43	2922	3506	4091	4675
8L	5	N	1.6	D		12.83 –	–	4.11		2.33	1.48		1.02	0.82		5.43	2922	3506	4091	4675
8P	5	N				.	–	4.11		2.33	1.48		1.02
9D	5	N	1.6	D		-11.83	–	4.11		2.33	1.48		1.02	0.78		5.43	2779	3335	3891	4447
AAP	5	N		P	95 / 112	.	—	4.11		2.33	1.48		1.02	0.82		4.57	2459	2951	3443	3935
AAR	5	N		P	112	.	—	4.11		2.33	1.48		1.02	0.82		4.57	2459	2951	3443	3935
AAS	5	N	1.6	TD		.	—	4.11		2.33	1.48		1.02	0.82		4.83	2599	3119	3639	4159
ABK	5	N		P	60	– 16.7.89	—	4.11		2.33	1.48		1.02	0.82		4.83	2599	3119	3639	4159
ABL	5	N		P	60	8.84 – 16.7.89	—	4.11		2.33	1.48		1.02	0.82		4.83	2599	3119	3639	4159
ABM	5	N		P	73 / 78 / 90	8.84 –	—	4.11		2.33	1.48		1.02	0.82		4.83	2599	3119	3639	4159
ABN	5	N		P	73 / 78 / 90	8.84 –	—	4.11		2.33	1.48		1.02	0.82		4.83	2599	3119	3639	4159
ABP	5	N	1.6, 1.7	D		8.84 –	—	4.11		2.33	1.48		1.02	0.82		5.5	2960	3552	4144	4736
ABR	5	N	1.6, 1.7	D		8.84 –	—	4.11		2.33	1.48		1.02	0.82		5.5	2960	3552	4144	4736
AFJ	5	N	2.5, 2.6	P(SA)		.	—	4.11		2.33	1.48		1.02	0.82		4.83	2599	3119	3639	4159
AGT	5	N		P	87 / 95	.	—	4.11		2.33	1.48		1.02	0.82		4.83	2599	3119	3639	4159
ASL	5	N		P	88 / 93 / 95	.	–	4.11		2.13	1.48		1.02	0.85		4.57	2549	3059	3569	4079
ASM	5	N		P	60 / 78	17.7.89 –	–	4.11		2.13	1.48		1.02	0.85
ASN	5	N	1.7	D		17.7.89 –	–	4.11		2.13	1.48		1.02	0.82		5.5	2960	3552	4144	4736
ASP	5	N	1.7	D		17.7.89 –	–	4.11		2.13	1.48		1.02	0.82		5.5	2960	3552	4144	4736
ASR	5	N	1.6	TD		17.7.89 –	–	4.11		2.13	1.48		1.02	0.82		4.83	2599	3119	3639	4159
ASS	5	N	1.6	TD		17.7.89 –	–	4.11		2.13	1.48		1.02	0.82		4.83	2599	3119	3639	4159
DV	5	N		P	60	-11.83	–	4,11		2.33	1.48		1.02	0.78		4.86	2488	2985	3483	3980
DW	5	N		P	78	-11.83	–	4,11		2.33	1.48		1.02	0.78		4.86	2488	2985	3483	3980
DX	5	N	1.6	D		-11.83	–	4,11		2,33	1.48		1.02	0.78		5.43	2779	3335	3891	4447
AST	5	N		P	95	.	–	4.11		2.13	1.48		1.02	0.85		4.57	2549	3059	3569	4079
VW T3 Syncro Gearboxes
AHF	4+G	Y	1.6	TD		5.3.86 – 31.8.89	6.03	3.78		2.06	1.23		0.78	—	6.03	5.43	2779	3335	3891	4447
AKE	4+G	Y	2.1	P		1.1.87 – 31.8.89	6.03	3.78		2.06	1.23		0.85	—	6.03	4.57	2549	3059	3569	4079
AKG	4+G	Y	2.1	P		10.11.86 – 31.8.89	6.03	3.78		2.06	1.23		0.85	—	6.03	4.57	2549	3059	3569	4079
AKK	4+G	Y	1.6	TD		1.4.89 – 31.8.89	6.03	3.78		2.06	1.23		0.78	—	6.03	5.83	2984	3581	4178	4775
ALE	4+G	Y	2.1	P		1.9.89 –	6.03	3.78		2.06	1.23		0.85	—	6.03	5.83	3252	3902	4553	5203
ALK	4+G	Y	2.1	P		1.8.87 – 31.8.89	6.03	3.78		2.06	1.23		0.85	—	6.03	5.43	3029	3635	4240	4846
AND	4+G	Y (16″)	1.6	TD		1.1.88 – 31.8.89	6.03	3.78		2.06	1.23		0.85	—	6.03	6.17	3442	4130	4818	5507
AVF	4+G	Y	1.6	TD		1.9.89 –	6.03	3.78		1.88	1.23			–	6.03	5.83
AVH	4+G	Y		P		1.9.89 –	6.03	3.78		1.88	1.23		0.85	–	6.03	5.43	3029	3635	4240	4846
AVJ	4+G	Y	1.6	P		1.9.89 –	6.03	3.78		1.88	1.23			–	6.03	5.43
AVK	4+G	Y	1.6	P		1.9.89 –	6.03	3.78		1.88	1.23		0.78	–	6.03	5.43	2779	3335	3891	4447
AVL	4+G	Y	1.9, 2.1	P		1.9.89 –	6.03	3.78		1.88	1.23			–	6.03	5.43
AVM	4+G	Y	1.9, 2.1	P		1.9.89 –	6.03	3.78		1.88	1.23			–	6.03	5.83
AVN	4+G	Y	1.9, 2.1	P		1.9.89 –	6.03	3.78		1.88	1.23		0.85	–	6.03	4.86	2711	3253	3795	4338
AVR	4+G	Y	2.1	P		1.9.89 –	6.03	3.78		1.88	1.23		0.85	–	6.03	5.83	3252	3902	4553	5203
AVS	4+G	Y	1.6	TD		1.9.89 –	6.03	3.78		1.88	1.23		0.78	–	6.03	5.83	2984	3581	4178	4775
AVU	4+G	Y (16″)	1.6	TD		1.9.89 –	6.03	3.78		1.88	1.23		0.85	–	6.03	6.17	3442	4130	4818	5507
AVV	4+G	Y	1.9, 2.1	P		1.9.89 –	6.03	3.78		1.88	1.23		0.85	–	6.03	4.86	2711	3253	3795	4338

Modified Gearbox

Green = 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 codes	No of Gears:	Syncro?	Disp.:(litres)	Fuel:	Power:(BHP)	Date:	G	1	2	3	4	5	R	Final Drive:	50	60	70	80
Some examples of modified boxes with different gearing
DH		4	N	1.6	D	50	-31.7.82	–	3.78	2.06	1.23	0.82	–		5.43	2922	3506	4091	4675
Same gearbox with a 4.14 Crown and Pinion
DH		4	N	1.6	D		10.82 –	–	3.78	2.06	1.26	0.82	–		4.14	2200	2700	3150	3600
4D	4	N		P	60	-7.84	–	3.78	2.06	1.26	0.85	–		4.57	2549	3059	3569	4079
Same gearbox with a longer 3rd and 4th gear
4D	4	N		P	60	-7.84	–	3.78	2.06	1.02	0.78	–		4.57	2350	2800	3270	3750
3H	5	N	1.6	D		-1.85	–	4.11	2.33	1.48	1.02	0.82		4.83	2599	3119	3639	4159
Same gearbox 4.14 crown and pinion
3H	5	N	1.6	D		-1.85	–	4.11	2.33	1.48	1.02	0.78		4.14	2150	2550	3000	3400
Syncro AHF
AHF	4+G	Y	1.6	TD		5.3.86 – 31.8.89	6.03	3.78	2.06	1.23	0.78	—	6.03	5.43	2779	3335	3891	4447
Syncro AHF converted to TDI with longer 3rd and 4th and bigger tyres 215/75/15
AHF	4+G	Y	1.6	TD		5.3.86 – 31.8.89	6.03	3.78	2.06	1.09	0.7	—	6.03	5.43	2300	2770	3250	3700

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

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

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

Custom Gears these are also usually Heavy Duty gears and are available in a range of ratios for both 3^rd and 4^th gears (4^th and 5^th 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 [email protected] and I will be more than happy to go through the details with you,

Thanks,

Paul

The tables on this page were compiled from these sources:

Types of VW T3/ T25 gearboxes

Quick Example

More Info

Recent Posts

Archives

Common VW Van Gearbox Codes

Types of VW T3/ T25 gearboxes

Quick Example

More Info

Recent Posts

Archives

Common VW Van Gearbox Codes

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