What is the difference between an in-frame kit and overhaul kit?
Mar 2016 22

Engines are the lifeblood of every imaginable high- pressure mechanical activity known to man, subjected to extreme pressures as the result of external and internal combustion processes that generate mechanical energy. They are responsible for making our cars run, generating power for electricity, hauling heavy stuff – they benefit us humans by taking over the work that our limited strength and power could not muster.
For the automobile industry, there are generally two types of major remedial measures used for engines – in-frame and overhaul (Out-of-frame) jobs and both require rebuild kits to replace damaged or worn-out parts.
What is the difference between an in-frame kit and an out-of-frame overhaul kit? The contents of the kits – an in-frame kit has less components compared to an overhaul kit.
Although both in-frame and overhaul jobs are focused on fixing engine performance issues, the in-frame repair process deals with rebuilding an engine without the need to remove the front cover or crankshaft of the engine.
Because of this, the in-frame kit does not contain gaskets for the front and rear body of the engine, only the main bearing, rod bearings, cylinder kits, upper gasket kit and oil pan gasket. The engine stays inside the vehicle frame without the need to be taken out of the vehicle body. In general, the in-frame process is intended mostly for regular preventive maintenance.

Out-of-Frame Overhaul Kit

An out-of-frame overhaul kit contains much more, as the overhaul process requires the engine to be removed from the frame of the vehicle. The rebuild process often requires engine block re-facing to smooth-en out the surface and cylinder re-boring to adjust clearances within the cylinder holes. During this process, then entire engine is disassembled.
An overhaul kit comes complete with cylinder kits, main bearings, rod bearings, front and rear crankshaft seals and complete overhaul gasket kit.
Costs vary between the two rebuild types. The overhaul repair process would cost much more, depending on the size of the engine, the amount of work and the parts needed for replacement or repair. Labor costs are often exclusive of the cost for overhaul kits.
When in doubt, always make sure to consult a specialist for the best and cost-effective advice for your engine repair and maintenance needs.

Types of Engine Rebuild Kits

Re-Ring Engine Rebuild Kit Includes piston rings, main bearings, rod bearings, thrust washers, upper gasket kit, oil pan gasket
In-frame Engine Rebuild Kit Includes piston & liner kits (or re-bore kits), main bearings, rod bearings, thrust washers, upper gasket kit and oil pan gasket
Out-of-frame Engine Rebuild Kit Includes piston & liner kits (or re-bore kits), main bearings, rod bearings, thrust washers, overhaul gasket kit and front & rear crankshaft seals
Piston-less In-frame Engine Rebuild Kit Includes liner kits, main bearings, rod bearings, thrust washers, upper gasket kit and oil pan gasket
Piston-less Out-of-frame Engine Rebuild Kit Includes liner kits, main bearings, rod bearings, thrust washers, overhaul gasket kit and front & rear crankshaft seals