Heavy-Vehicle Gaskets and Sealing

Both manufacturing and supply, by choice

KMQ-branded gaskets and O-ring sets are our own products. Alongside them we source from manufacturing partners we have worked with for years and from brands such as Reinz, Elring and Corteco. That is deliberate: being able to offer both an economical and an original-equivalent option for the same engine is more useful than being tied to a single brand. Which brand each item comes from is shown openly on the product page.

Gasket sets (upper set, full set)

A gasket set brings together the gaskets needed for one engine job. An upper set generally covers the cylinder head area; a full set goes down to the sump and lower group. Set contents vary by engine and emission class — the EURO 3 and EURO 4/5 versions of the same engine do not take the same set. That is why engine code and emission class are always asked for together.

Cylinder head gasket

The cylinder head gasket separates combustion pressure from the coolant and oil galleries. Its thickness grade depends on whether the engine has been machined; on a skimmed surface a standard-thickness gasket will not give the correct clamping. The wrong thickness leads to oil and water mixing and, in the worst case, a cracked head. The engine’s overhaul history should be established before ordering.

Sump, rocker cover and manifold gaskets

The sump gasket handles oil sealing, the rocker cover gasket the top cover area, and the intake/exhaust manifold gasket the hot gas path. Material matters most on the manifold side: a gasket made from the wrong material will leak again within a short time. Even on vehicles with the same engine code, manifold gasket type can vary with specification.

Seals, O-rings and sealing elements

Front and rear crankshaft seals, pinion seals, compressor throat O-ring sets and gearbox seals make up the rest of the sealing family. For these items the product name is not distinctive; dimensions decide — inner diameter, outer diameter and height. If you still have the old part, measuring it is the fastest route.

Information needed for the right gasket

Three pieces of information are almost always enough: engine code, emission class (EURO 3 / EURO 4-5) and whether the engine has been overhauled before. If you have the chassis number, we can derive all three. Dimension-critical seals and O-rings also need measurements. If something is missing, we ask before shipping.

Gaskets by engine

Frequently asked questions about gaskets

What is the difference between a full set and an upper set?

A gasket set puts everything one engine job requires into a single order, so instead of hunting down individual parts you order a ready-made kit. It comes in two scopes. An upper set is enough whenever only the cylinder head is opened, and it covers the gaskets in that area. A full set adds the sump and lower-group gaskets on top, and suits a complete engine overhaul. Which one is required depends on how deep the job goes: buying a full set for a head-only job means paying for items you will not use, while an upper set will not finish a lower-group job. Set contents also change with engine code and emission class, since different emission versions of the same engine call for a different parts list. That is why the job being done and the emission class should both be stated when ordering; a set sent without that information risks having the engine opened twice.

Are the EURO 3 and EURO 4/5 gaskets for the same engine identical?

No, the same engine code can call for different set contents depending on emission class. An engine's EURO 3 version and its EURO 4/5 version may share the same block, but the changes emissions rules force onto the engine carry through to the dimensions or type of some gaskets in the set. As a result, the sets sold for the two classes are not always interchangeable; swapping one for the other often means only one or two items are wrong, not the whole set, which makes the mistake harder to spot. Giving the correct engine code is not enough on its own: an order placed without the emission class can still arrive with the wrong set even when the code matches. That is why the emission class must be stated together with the engine code when requesting a set, and prior overhaul history is a separate factor that shapes which set is correct.

Which head gasket is needed if the engine has been machined?

On a skimmed engine the gasket thickness grade changes. The correct grade can only be established after measurement; it should not be guessed.

How do I choose between a KMQ gasket and another brand?

Both may suit the same application. Budget, lead time and how hard the vehicle is worked decide. When we receive your request we present both options with prices.