The Unimog 406 and 416 series vehicles are equipped with the UG 2/27 transmission.

The code "UG 2/27" can be interpreted as "Unimog transmission, second series, 270 N-m input torque" and this specific unit has more than ten variants.

Numerous improvements were phased in at various times between 1963 and the end of production in 1989, including an improved splitter gear, enhanced transmission lubrication, better venting, and a changed tooth count for the PTO drive and driven gears.

The "F" type transmission used in older models was eventually replaced by the "G" type transmission, which was designated with the model number 717.800. Later, further improvements were made to the G-type, resulting in the final version with the model number 717.801.

Let's examine these three distinct periods:

• F-Type Transmission: Used in vehicles produced from the start of production in 1963 until August 1968 (Chassis number up to -009058 and transmission number up to -010398).

• G-Type (717.800) Transmission: Used in Unimog 406 and 416 models produced from August 1968 to November 1976 (Chassis numbers -009059 to -028718; transmission numbers -010399 to -056864).

• G-Type (717.801) Transmission: Used in all Unimog 406 and 416 models produced from January 1977 until the end of production in 1989 (Chassis number from -028719 and transmission number from -056865 onwards).

And I want to add that info I get it from Eric van Mierlo of VAM PARTS:

"All F and G types gearboxes are synchronised, and they share all the same synchroniser rings as the older 404 / 411 transmission (only the 5 gear ring is replaced later by a steel version because of too much wear)."
 

Unimog 406 & 416	Date	Chassis number	Transmission number	Transmission serie	Transmission type
	1963 > August 1968	0 > -009058	0 > -010398	UG 2/27	F
	August 1968 > November 1976	-009059 > -028718	-010399 > -056864	UG 2/27	G 717.800
	January 1977 >	-028719 >	-056865 >	UG 2/27	G 717.801

How to distinguish between "F" and "G" types?

• F-Type: On the right side of the transmission (in the direction of travel), there is a small pentagonal cover.

• G-Type: In the same location on the right side, there is a pentagonal raised casting (embossment) rather than a cover. This is easily identifiable from the outside.

If you see a casting instead of a cover, you have a G-type transmission. To determine if it is a 717.800 or 717.801, you must check the serial numbers.

Unimog F type gearbox

Unimog G type gearbox

Unimog F type gearbox

Unimog G type gearbox

Unimog F type gearbox

Unimog G type gearbox

Unimog F type gearbox

Unimog G type gearbox

Unimog F type gearbox

Unimog G type gearbox

Unimog F type gearbox

Unimog G type gearbox

Unimog F type gearbox

Unimog G type gearbox