Product details
Mannol 9986 Gearbox Oil Additive with Leak-Stop Sealant for Manual Transmissions
Ever spotted a sneaky drip or a bit of seepage from your manual gearbox seals? Mannol 9986 could be just the ticket. This nifty little additive is specially designed to tackle leaks caused by worn or stiffened rubber seals and O-rings in manual gearboxes. Rather than rushing to replace seals or parts, you simply add it to your gear oil and let the seals soften up and bounce back to their original flexibility.
How It Works and What It Does for You
The cleverness lies in its unique formula, which not only plugs current leaks but also slows down the ageing process of those seals. Using Mannol 9986 as a preventative measure can keep your gearbox ticking over nicely for longer – a proper bonus if you want to dodge unexpected drips and pricey repairs down the line.
Compatibility and Usage
One of the best bits? It plays nicely with all types of manual transmission gear oils, so no faffing about trying to find the right one. Whether your motor has a manual, auxiliary, or differential gearbox, this additive fits the bill. A 180 ml bottle treats up to 5 litres of transmission oil, and you can add it at any time – no need to wait for an oil change. For top-notch results, it’s wise to top up with every gear oil change. If the leaks are a bit more stubborn, two bottles should do the trick.
Technical Details and Practical Benefits
It comes in a handy 180 ml vial, tipping the scales at 180 grams, making it easy to stash in your garage or toolkit. Made by Mannol, a trusted name in automotive additives, regular use means you can kiss minor leaks goodbye before they turn into major headaches. Plus, it’s dead simple to use—no special tools or tricky procedures required.
Why Choose Mannol 9986?
If you’re after a no-nonsense, cost-effective way to keep your manual gearbox in good nick and leaks at bay, this additive ticks all the boxes. Perfect for anyone who wants to look after their vehicle without forking out on expensive repairs. Just pour it in and let it crack on – job done.



