JHZR2
Staff member
On my Cummins. Was a bit harder than on my Mercedes. I couldn’t find TDC with the pin per the FSM. Not 100% sure why. Also less definite than my Mercedes engines in terms of knowing when the engine is in the right position. On the Mercedes you can easily eyeball when the base circle is in the right spot. Not so easy on the Cummins. Plus barring the engine is harder based upon where the tool is inserted. The Mercedes engines are designed to be turned from the crank.
It took me a while to figure out when the valves were in overlap. I didn’t have the right set of U-joints the first time, so I was turning the engine two ratchet clicks at a time, and trying to see incremental valve motion. Today I gathered the right parts and could move the engine more at any time. So it was easier to see when one valve had come all the way up and the other was just starting to move (overlap).
Most valves were a bit tight. The way the cam is set, when one set of valves is in overlap, the other paired cylinder is at TDC. So then you can adjust the partner. They are paired as:
1&6
2&5
3&4
Intake is supposed to be 0.01in, exhaust 0.02; my initial measurements were:
2 overlap: 5E= 0.016; 5I=0.007
3 overlap: 4E= 0.022; 5I=0.008
5 overlap: 2E=0.019; 2I=0.008
4 overlap: 3E=0.018; 3I=0.007
6 overlap: 1E=0.021; 1I=0.005
1 overlap: 6E=0.015; 6I=0.008
No idea if/when it was done last.
All VC seals seemed ok. Seemed like a greater risk of introducing dirt to remove and clean, than to just leave them. I’ll replace when I see seepage. Definitely better seals than what is used on the VC on my Mercedes diesels. Those seals are always leaky and hard...
Nothing really changed, and I wasn’t really expecting it to. Maybe really cold weather starts (which fired off perfect anyway) might have a bit less smoke (wasn’t much anyway. Maybe better/cleaner combustion? This truck just runs so well/free/smooth, so there wasn’t any real concern, just baselining maintenance.
I did see a bit of oily residue, not sure if varnish or what. It was soft and wiped off. Everything else very clean.
I’m glad I did it even if a bit annoying (and painful to contort and get scratched to do the rear ones.
It took me a while to figure out when the valves were in overlap. I didn’t have the right set of U-joints the first time, so I was turning the engine two ratchet clicks at a time, and trying to see incremental valve motion. Today I gathered the right parts and could move the engine more at any time. So it was easier to see when one valve had come all the way up and the other was just starting to move (overlap).
Most valves were a bit tight. The way the cam is set, when one set of valves is in overlap, the other paired cylinder is at TDC. So then you can adjust the partner. They are paired as:
1&6
2&5
3&4
Intake is supposed to be 0.01in, exhaust 0.02; my initial measurements were:
2 overlap: 5E= 0.016; 5I=0.007
3 overlap: 4E= 0.022; 5I=0.008
5 overlap: 2E=0.019; 2I=0.008
4 overlap: 3E=0.018; 3I=0.007
6 overlap: 1E=0.021; 1I=0.005
1 overlap: 6E=0.015; 6I=0.008
No idea if/when it was done last.
All VC seals seemed ok. Seemed like a greater risk of introducing dirt to remove and clean, than to just leave them. I’ll replace when I see seepage. Definitely better seals than what is used on the VC on my Mercedes diesels. Those seals are always leaky and hard...
Nothing really changed, and I wasn’t really expecting it to. Maybe really cold weather starts (which fired off perfect anyway) might have a bit less smoke (wasn’t much anyway. Maybe better/cleaner combustion? This truck just runs so well/free/smooth, so there wasn’t any real concern, just baselining maintenance.
I did see a bit of oily residue, not sure if varnish or what. It was soft and wiped off. Everything else very clean.
I’m glad I did it even if a bit annoying (and painful to contort and get scratched to do the rear ones.
. Keep the miles coming.
