Cummins O-Ring & Overhaul Kits — part numbers

33 numbers covering complete overhaul kits, O-ring kits, liner seal kits and the packaged sets used for major service work.

The smallest category in the catalogue and the one with the highest value per line. An overhaul kit is a single number covering what would otherwise be dozens of individual orders, and getting the right one is largely a question of establishing the scope of work accurately before ordering rather than of finding a part number.

Kits are defined by scope, and the scopes overlap confusingly. An upper-end kit, a lower-end kit, a complete overhaul kit and a liner and seal kit contain different things, and the naming is not consistent across engine families. Rather than matching a kit name to a job title, tell us what you are opening and what you intend to replace, and we will tell you which kit covers it and what falls outside.

The most common gap: overhaul kits generally do not include bearings, and bearing size depends on what is currently fitted. Budget them as a separate line from the start rather than discovering it mid-strip. Similarly, kits are specified for standard bores — if the block has been bored oversize previously, several items in the kit will be wrong, and we need to know before quoting rather than after shipping.

On tier, complete overhaul kits are one of the few places where we generally recommend genuine without much hedging. A kit is only as good as its weakest seal, and the labour cost of an overhaul dwarfs the parts difference. Where a good branded alternative exists we will quote it alongside, but we will say which we would fit.

For a quotation: engine serial, CPL, bore condition and history, and a description of the work being done.