LOTS of things are assembled off-line and then the complete assemblies go onto the car.
Whether this happens before or after the engine (drivetrain subassembly module) is quite another matter.
For example, one manufacturer might choose to install the pre-assembled instrument panel subassembly into the vehicle after the engine goes in ... and another manufacturer might choose to install it before the engine goes in.
I deliberately chose a subassembly that is completely unrelated to the engine in order to illustrate why you need to clarify your question.
As Brian says. In the assembly line I am used to, the engine, driveline and subframes are assembled into a cradle, the trimmed body is then dropped on top of the raised cradle at the start of the Final Line, and the guys in the pit do all the bolts up, put the wheels on, the cradle drops away and the car is lowered onto the tracks. On the other hand at Lotus we used to slot the engine in from above just like a mechanic.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376
I add here some clarification to the question.
Some assemblies like AirFilter to Engine Connection , Turbocharger to Intercooler connection should be assembled after Engine assembly right? My understanding.
Likewise what are all the assemblies in Engine Room , that are assembled after the integration of Engine in the assembly line.
And I also having to ask, For example Whether Airfilter,Airducts assy connected after engine integration or before engiine integration in assy.
OK so the question is whether the engine auxiliary components go in with the subframe or before or afterwards.
Almost invariably, the air filter housing, radiator, intercooler, and some electrical components are not part of the engine cradle/subframe when it goes into the vehicle. So they go in either before, or afterwards.
But whether they go in before or after ... will vary. One vehicle design may be done one way, another one done a different way.
Whatever facilitates the most straightforward assembly process, is the right way to do it.
A lot of the auxiliary components (various gizmos and gadgets mounted on the firewall, wiring harness, etc) are easiest to get access to before the engine is in the way ... so they go in first.
Some vehicle designs might not have enough clearance for the powertrain to go in if the radiator/intercooler is in place ... so the radiator might go in afterward. But in other designs, it might not matter ... so it's whatever is most convenient on the line. Or if it doesn't matter, perhaps someone just makes an arbitrary decision about which way to do it. Or they do it in a certain order because "that's how we've always done it". Sometimes, that's just how it is.
A lot of vehicle manufacturers at least partially design the vehicle around the assembly sequence, and they *always* assemble everything in the same order, "just because".
