Gearbox Stop Leak

An additive to revitalise old gearbox oil seals and to prevent annoying oil leaks due to seal wear and ageing.

scroll me

Features & Benefits

  • Revitalises old gearbox oil seals - stops and prevents most oil leaks caused by general seal wear, reduces oil consumption
  • Effective on many seal & gasket materials, such as rubber, neoprene, EPDM, viton etc. and compatible with all gearbox oils for manual gearboxesn in petrol and diesel powered cars - universal applications, reduces inventory
  • Contains gearbox oil anti-wear, detergent and dispersant nadditives - does not compromise existing gearbox oil performance, maintains oil viscosity
  • No dismantling - saves time and money


250 ml Brown 86523 SDS TDS


Gearbox oil seals, ‘O’ rings and gaskets in modern petrol and diesel powered cars are subject to high demands over their service lives. As vehicles age, these materials can ‘dry’ out and shrink, leading to messy oil leaks. The addition of KENT Gearbox Stop Leak can revitalise old seals and reduce or eliminate annoying oil leaks.
It’s suitable for use with all gearbox oils for manual gearboxes and effective on many seal and gasket materials, such as rubber, neoprene, EPDM, viton etc.
KENT Gearbox Stop Leak also contains a fully formulated additive package to maintain effective levels of lubrication and wear prevention.
It can be beneficial in vehicles with visible gearbox oil leaks.


One 250 ml bottle of KENT Gearbox Stop Leak will treat engines with a gearbox capacity of up to 4 litres of gearbox oil. Add a full bottle via the gearbox filler plug, or as recommended in the owner’s handbook.
Pay attention not to exceed manufacturers specified maximum oil level. May take several hundred kilometres to take full effect. A minimum gearbox oil level of 2 litres is required for the application of one full bottle of Gearbox Stop Leak.
Will not prevent oil leaks caused by damaged components. KENT Gearbox Stop Leak is not a replacement for good vehicle maintenance. Gearbox oil level should always be at least at the minimum recommended by the manufacturer. Not suitable for use in automatic gearboxes.
At ambient temperatures below 15° C the product becomes opaque. On warming to above 15 °C the product becomes clear once again. This phenomenon does not affect the product stability or performance.