Camshaft Bearing lube

I’m adjusting the valves on my 4.2 engine and the only one that was out was #6 exhaust at .003. When I removed the camshaft I noticed that the cam bearings were a little worn so I’m replacing them. The camshaft is in good condition and to spec.

What type of lube should I use on the new bearings on re-assembly. Is there anything else I should do at the same time?

Photo of Upper half of cam bearing shells.

Thanks Andy 69 FHC

Just engine oil, is sufficient.

When my 2+2 engine was rebuilt the shop used this stuff:

If the cam had been replaced as well as the bearing shells then yes but just new shells I would go as wigs states, just engine oil.

Using assembly lube won’t hurt.

Won’t hurt, but 105 is more for long-term storage: if the head will be put into service fairly soon, oil will suffice.

I have always used a 50-50 mix of STP and motor oil when I assemble an engine. Sometimes it’s a year or two before I get around to starting it.

as to the what else: clean out cam oilways while out: use care when installing the bearing shells as it is…easy to damage one…helps to have a second set on hand) be sure caps go back exactly same place and orientation: …tighten down slowly evenly across all…to specified torque…and no more. Nick

I should think so, yes, but I’d also pour oil all around before sealing up the cam covers so the oil pump doesn’t have to do all the work.

Also Andy, not sure which order those are in. Is the one on the right the front one? It seems like it might have the most wear. Make sure your upper chain isn’t dead tight. I’ve always backed mine off one click from tight.

Just out of curiosity- I clearly am not versed at identifying bearing issues, but should I be seeing those bearings as in need of replacement?


Not desperately no, but it depends how the bottoms look. They’re cheap enough to do as a “while I’m here thing”. Valve adjustments aren’t something that gets done too often.

I‘d say left ist front as the chain pulls down at the front and the most bearing wear should be on the center-and rearmost. The first bottom shell should wear as well but the springs are more powerful?
The wear looks normal and I‘d change them while here. They will work though. If you replaced the used ones, don’t mix them up. Keep the numbering of the caps, obviously, and follow the tightening procedure.
The oil pump only feeds to the bearings, so sloshing something over the tappets is nice and also at the parts below, but nothing the oil pump would care about much.

Thanks guys and Erica for all your sage advise. The bearings caps are in order from front to back. There is more wear on the bottom front bearing than on the top half. As you say while I’m in there its a good idea to do it; and they cheap enough. BTW the front #6 tappet had a wear spot so I’m replacing that as well and will have to remeasure the old tappet and the new one to calculate the new shim size.

Thanks Andy S2 FHC

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Andy if the wear is just on one side, you can just flip it. The valve stems leave little depression marks but when flipped over that mark is inside the overall contact area on the tappet.

Edit: reading comprehension fail…

I think he was referencing the tappet, not the lash pad.

Ah, yes that is a different story.

Pre lubing your engine is most important before starting for peace of mind . its simple so why not


If you replace the camshaft bearings expect to have to re-shim the clearances - particularly the front one. Check them all.


Iskendarian Moly cam assembly lube.

I use some assembly lube, but more importantly, when I get it all buttoned up I turn the engine over by hand a couple of revolutions, then disconnect the coil wire and use the starter to turn it over enough to get oil pumping. That way everything is nice and lubed before I fire the engine.