Using assembly lube on an already broken in engine

07sierra8.1 · August 20, 2019

Hello all,

I am working on putting my 1986 K20 back together. I pulled the motor out to change the clutch and refinish the frame rails in the front. The engine was rebuilt back in the early 2000s, however the previous owner (my father) lost the built sheet for the engine. So while I had the engine out I pulled the cam to get the specs on that and fix a few small issues with the motor as well as repaint it. We figure the engine only has roughly 35-45k miles on it since rebuild since the truck sat and only was driven 3-4 times a year.

My question is, when putting the cam back in, do I need to use assembly lube on the lobes and bearings or just coat them with a thin layer of oil and put it back in? The Lifters and push rods are all going back into the respective location that they came out of. So all the parts that have broken in together are back with their mated surfaces so I would assume just oil will be fine but I am not 100% sure with that???

Jglew82 · August 20, 2019

Just use good clean engine oil if you are going back with the same parts in the same locations. Also good practice to prime the oil pump before starting.

MaverickZ71 · August 20, 2019

Great looking truck!

07sierra8.1 · August 20, 2019

1 hour ago, MaverickZ71 said:

Great looking truck!

Thank you. My father bought it used in 1988. Him and I restored it in 2001. When it was restored, you were still able to get OEM body parts from GM. Currently the only body parts on it that are not GM are the cab corners and Rockers since to get those in original GM, he would have had to buy the whole door opening of the cab. The aftermarket rockers are the only thing that rotted back out. Everything else is solid. He handed the truck down to me in 2012. I am slowly going through and restoring things over again since it has pretty much sat outside since it was restored.