ttyR2

I'm not sure about the 1997 LS400, but the factory service info for my 1990 '400 shows shim-over-bucket valve actuation with no lifters. The cam rides directly on the shims (the shims are a wear surface) and push directly on the valve stem with no rocker arm. That's the reason this engine needs valve adjustments and engines with lifters like Chevy's don't (not that I'd put a Lexus and Chevy engine in the same league :-)

CptnTonus

Interesting. I work for an auto-parts company, and we have a listing on lifters for the early LS400's. My supplier calls them cam followers, but that's what they call them for every car.

The reason *some* Chevys don't need their valves adjusted is because they use hydraulic lifters. If they had a solid lifter, there would be a required valve adjustment.

SW07ES

Almost correct. On the 1990-97 LS engines, the camshaft lobe rides directly on the valve adjustment shims, BUT these shims sit inside a bucket shaped VALVE LIFTER. The top of the valve stem contacts the underside of this bucket shaped VALVE LIFTER. It's a mechanical valve lifter arrangement with no hydraulics, pushrods or rocker arms.

90% of owners don't realize and appreciate how much smoother and more powerful their engines will run if they adjust the 32 valve clearances on their LS motors precisely. So few owners ever have their clearances adjusted and some complain of ticking noises, low power etc.

Bradster

Would you only trust a Lexus mechanic to adjust the 32 valves and how much would that cost?

ripp

my 1990 lexus with 115 000 km, never change pieces, all original.

SW07ES

I'd trust a Lexus dealer, Toyota dealer or independent Toyota specialty shop.