M32 Gearbox 3rd / 4th Gear Synchro Gen 3 55599121 55512804 2016 Onwards

M32 Transmission 3rd Generation

3rd / 4th Gear Synchromesh Ring

55599121 2016 Onwards

Superseded: 55512804

2 Required Per Gearbox (23).

This is a three part synchromesh design for 3rd and 4th gear on the 2016 onwards M32 gearbox.

M32 GEN 3 2016 Onwards Only

Part Number(s)

55599121

Fitment Location 23 On Diagram

Vehicle Compatibility

Abarth
Abarth Grande Punto, 199 (2007-2009)
Abarth Punto, 199 (2012-2014)
Abarth Punto Evo, 199 (2010-2012)

Alfa Romeo
Alfa Romeo (EU) 147, 937 (2000-2010)
Alfa Romeo (EU) 156, 932 (1997-2007)
Alfa Romeo (EU) 159, 939 (2005-2011)
Alfa Romeo (EU) Brera, 939 (2006-2011)
Alfa Romeo (EU) Giulietta, 940 (2010-2021)
Alfa Romeo (EU) GT, 937 (2004-2011)
Alfa Romeo (EU) Mito, 955 (2008-2020)
Alfa Romeo (EU) Spider, 939 (2006-2011)

Chevrolet
Chevrolet (EU) (Daewoo) Cruze, J300 / J305 / J308 (2009-2014)
Chevrolet (EU) (Daewoo) Orlando, J309 (2010-2014)
Chevrolet (EU) (Daewoo) Trax / Tracker (2013-2014)
Chevrolet (EU) (Daewoo) Aveo, T300 (2011-2014)
Chevrolet (EU) (Daewoo) Malibu, V300 (2011-2015)
Chevrolet (USA / CAN) Cruze, J300 (2010-2016)
Chevrolet (USA / CAN) Cruze (2016-2020)
Chevrolet (USA / CAN) Sonic, T300 (2012-2020)

Opel
Opel ADAM, M13 (2013-2019)
Opel Astra H, A04 (2004-2010)
Opel Astra H TwinTop, A04 (2006-2010)
Opel Astra J, P10 (2009-2018)
Opel Astra K, B16 (2015-2022)
Opel Cascada, W13 (2013-2019)
Opel Corsa D, S07 (2006-2015)
Opel Corsa E, X15 (2015-2019)
Opel Insignia A, G09 (2008-2017)
Opel Insignia B, Z18 (2017-2022)
Opel Meriva A, X03 (2003-2010)
Opel Meriva B, S10 (2010-2017)
Opel Mokka, J13 (2012-2016)
Opel Mokka X, J13 (2016-2019)
Opel Zafira B, A05 (2005-2014)
Opel Zafira C, P12 (2012-2019)
Opel Signum, Z03 (2003-2008)
Opel Vectra C, Z02 (2002-2009)

Vauxhall
Vauxhall ADAM, M13 (2013-2019)
Vauxhall Astra H, A04 (2004-2010)
Vauxhall Astra H TwinTop, A04 (2006-2010)
Vauxhall Astra J, P10 (2009-2018)
Vauxhall Astra K, B16 (2015-2022)
Vauxhall Cascada, W13 (2013-2019)
Vauxhall Corsa D, S07 (2006-2015)
Vauxhall Corsa E, X15 (2015-2019)
Vauxhall Insignia A, G09 (2008-2017)
Vauxhall Insignia B, Z18 (2017-2022)
Vauxhall Meriva A, X03 (2003-2010)
Vauxhall Meriva B, S10 (2010-2017)
Vauxhall Mokka, J13 (2012-2016)
Vauxhall Mokka X, J13 (2016-2019)
Vauxhall Zafira B, A05 (2005-2014)
Vauxhall Zafira C, P12 (2012-2019)

Fiat
Fiat (EU) Bravo, 198 (2007-2015)
Fiat (EU) Croma, 194 (2005-2010)
Fiat (EU) Grande Punto, 199 (2005-2011)
Fiat (EU) Linea, 323 (2007-2014)
Fiat (EU) Punto Evo, 199 (2009-2012)

SAAB
Saab 9-5 (2010-2011)

As M32 gearbox rebuild and repair specialists, Eco Torque is proud to offer genuine gearbox parts as well as high quality aftermarket alternatives throughout its store.

Being one of the first companies in the UK to offer the M32 bearing and end-case upgrade, we pride ourselves on mastering the repairs of the gearboxes we work on.

Browse Eco Torque's ever-evolving product range available to purchase online
at competitive prices.

If you cannot find the items you need or are unsure if the part is compatible with
your vehicle make and model, please send us your UK registration number or
VIN Code and we will direct you to the right part.

Frequently Asked Questions

Which gearbox does this kit fit?

This 3rd/4th gear synchromesh ring (55599121, supersedes 55512804) fits the M32 (6 Speed) GEN 3 gearbox, 2016 onwards only. The gearbox code is stamped on the bellhousing — confirm before ordering.

What is included in this kit?

One three-part synchromesh ring for 3rd or 4th gear, fitment location 23 on the M32 exploded diagram. Two are required per gearbox to replace both 3rd and 4th.

Is this OEM quality?

Yes — this part is used across Vauxhall, Fiat, Abarth and Alfa Romeo applications and is supplied to OEM specification.

Do I need to drain the gearbox before fitting?

Yes — drain before beginning internal work. Follow the workshop manual for the correct drain and refill procedure.

Why Choose Eco Torque?

Eco Torque are UK-based transmission specialists with years of experience supplying quality gearbox parts. We stock genuine OE, OEM-quality and uprated aftermarket components, and our team can advise on the right part for your application. All orders are dispatched promptly with full tracking, and we back our parts with expert aftersales support.

Need Help Finding the Right Part?

Not sure if this is the right part for your vehicle? Contact our team — we're happy to help confirm fitment before you order. Use the contact form, email us, or call us directly.

Reference Number: ET2301