4040 head gasket

[LMD]

Putting a new head gasket on my 4040. Ordered the top end gasket kit from jd and the kit includes 2 head gaskets-a thin and a thick. My dealer isn't sure of which one i should use. Anyone have any idea which one i should use? Thanks

 

[Anonymous-0]

I have not read a John Deere shop manual in 15+ years, but I was at a Victor gasket meeting one time (Victor made the gaskets) and it has to do with piston protrusion if I remember correctly.

 

[buickanddeere]

Thinner is for more compression and better
starting. As long as clearance allows.
Your Deere engine service manual should cover this
topic?

 

[LMD]

I know i should probably own a service manual but usually my dealer is good about giving me any technical info i need. Until now of course.

 

[rexhellwig]

This is good news. I didn't know they were actually packaging a thick and thin gasket in the head sets again.

.009 is all you need to know, nine thousandths of an inch.

If any piston will rise .009 inch above the BLOCK, you must use the thick gasket. If they are all below .009, you want to use the thin gasket. This is only for the 404D engine. Don't try to use this spec on other engines. Don't measure to the liner steps. You want the maximum piston height above the block surface. This is from bulletin R77-20-7.