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+--- Thread: How much gear lube to add? (/showthread.php?tid=587)
How much gear lube to add? - Pirate_Freder - 07-06-2016
So I know Rawze explained this and he said that if you're engine is past 300k to just add a full gallon. I'm wondering how loose that is assuming the engine has become though. Seeing as the ISX doesn't do well with overly thick oil I certainly don't want to take it too far.
I have a 2010 KW 660 with a CM871 525hp with 318k. The main reason I am thinking I might want to go easy on the gear lube is because I only have 4.5" of blow-by, plus judging by the wheel horsepower it doesn't seem to have lost any. I'm not sure how correct they were but when I spoke to a Cummins shop about my dnyo/blow-by results their reaction was "Holy s#!*, that engine is like brand new". I'm leaning towards only half a gallon of Sta-Lube 85w90 in my Rotella-T dino 15w40. I would greatly appreciate some input on this as I am just going by my educated gut feeling.
RE: How much gear lube to add? - ynot - 07-06-2016
What's up with the fuel pressure?? It seems just a bit on the low side like 125-145psi lower then normal
RE: How much gear lube to add? - Pirate_Freder - 07-06-2016
(07-06-2016 )ynot Wrote: What's up with the fuel pressure?? It seems just a bit on the low side like 125-145psi lower then normal
Oh yeah, it was just a bad reading. Checked it with a gauge and it was within spec. I doubt it could even run with pressure that low lol.
RE: How much gear lube to add? - in2trux - 07-06-2016
18" on a manometer is Cummins spec? Seems like a very high number.
Take a look a Rawzes video of their engine, cams at 1M miles and he's been using it since new.
I try to replicate success and just started adding it again after 5000 miles on our inframe.
All the bearings that came out of our engine looked great at 670k, no copper showing.
It is cut 11:1 and at 210-220 degrees it is still thin. I'm seeing only a 10 psi drop between cold and hot, with a shimmed pump.
RE: How much gear lube to add? - Waterloo - 07-06-2016
I use the entire gallon in mine, fresh in frame, CM871, in the heat of the summer I doubt your motor will even know it is there, winter cut back to half a gallon. Also, does it still have the mandate? If it does, I would seriously look into an oil bypass filter to collect the soot. And do an EGR tuneup on her asap along with an overhead if you have yet to do that. Really get into the top of the motor and have a good look see. Just my .02
RE: How much gear lube to add? - Rawze - 07-06-2016
(07-06-2016 )in2trux Wrote: 18" on a manometer is Cummins spec? Seems like a very high number.
...
The spec for a CM871 is 457mm (17.9") on the official cummins gauge. Personally, I think it is way too lenient and there would be no way you could keep a DOC/DPF can happy if that blow-by is from the piston rings and oil consumption was occurring. I would think that oil consumption resulting from that much blowby would likely be high enough to constantly face-plug the DOC all the time.
I also find it curious as to why the blowby in that chart follows the boost pressure specifically, and not the RPM, torque/HP, or any other factor. -- Interesting.
could this be an indication that the turbo is making some of that blowby?
RE: How much gear lube to add? - Brock - 07-06-2016
I questioned the validity of rawzes gear oil claim. I am a synthetic man and run mobil delvac 1 le 5w30 whixh is a full group IV/V synthetic and not one of those "severely hydrocracked" group III b.s. synthetics that most people buy.
The reason I questioned his claims was because I think under the same principle as the bypass oil filter people.... Contaminants are what causes engine wear which is why rawze always recommends a bypass filter. I believed (and still do) That rawzes great success with his engine is due to amazing tuning which has the engine cleaner than ever thought possible, a amsoil bypass filter to take out whatever contaminants do arrive and a very rigorous oil change regiment.... I think personally that this is more to take the credit then the gear lube, He could probably run recycled vegetable oil from burger King and still have a nice looking motor.
But here's where it all changes. I pay $1350 cdn for a barrel of my oil and that's with a great discount, whereas I could fill my barrel with normal delvac 15w40 for $600 cdn.
I don't extend my oil changes just cause I run synthetic soi am spending way way more money on lube yet rawzes engine looked a million times better then mine does. He didn't even need to replace most of the parts he did in his rebuild whereas my motor at a million miles is about ready to explode. Why ever it works, it works and it works cheap.
It's a little late now as this motors nearing a teardown but I have switched to the gallon of gear lube... and I can't believe it cause I am very synthetic!
Results don't lie my friend.
RE: How much gear lube to add? - Rawze - 07-06-2016
(07-06-2016 )Brock Wrote: I questioned the validity of rawzes gear oil claim. I am a synthetic man and run mobil delvac 1 le 5w30 whixh is a full group IV/V synthetic and not one of those "severely hydrocracked" group III b.s. synthetics that most people buy.
The reason I questioned his claims was because I think under the same principle as the bypass oil filter people.... Contaminants are what causes engine wear which is why rawze always recommends a bypass filter. I believed (and still do) That rawzes great success with his engine is due to amazing tuning which has the engine cleaner than ever thought possible, a amsoil bypass filter to take out whatever contaminants do arrive and a very rigorous oil change regiment.... I think personally that this is more to take the credit then the gear lube, He could probably run recycled vegetable oil from burger King and still have a nice looking motor.
But here's where it all changes. I pay $1350 cdn for a barrel of my oil and that's with a great discount, whereas I could fill my barrel with normal delvac 15w40 for $600 cdn.
I don't extend my oil changes just cause I run synthetic soi am spending way way more money on lube yet rawzes engine looked a million times better then mine does. He didn't even need to replace most of the parts he did in his rebuild whereas my motor at a million miles is about ready to explode. Why ever it works, it works and it works cheap.
It's a little late now as this motors nearing a teardown but I have switched to the gallon of gear lube... and I can't believe it cause I am very synthetic!
Results don't lie my friend.
What you may be missing from that equation is the fact that the gear lube add a bunch of zinc, molly, etc. that gearboxes and engine also like. It increases the overall hydraulic pressure rating of the oil without adding too much viscosity, and that reduces wear to many components. It also adds a bit of sulphides (some say thats bad but I have proven otherwise), and the sulphides prevent dry-starts. My old pistons and wrist pins sat in a corner of the shop for 2 months and they were still so slick, just leaning them a very tiny bit to the side, and the wrist pins would slide right out like you had just poured oil all over them again. Other pistons from another engine were there and they were already starting to rust/were dry as a bone.
All I know is that it worked so well for me and my engine, that I would not consider anything else at this point. To me, I think the results were as good or better than anything else I have ever seen anyone do, and 80%~ of every ISX truck owner I have ever met that did high dollar synthetic + extended oil changes, no matter how well they kept after their bypass filters and sampling,.. ALWAYS ended up with chewed cams. The problem is that most of them are too damn stubborn to admit what they are doing is damaging because of all the brainwashing by the people who push that stuff off onto their victims.
Lastly,... here is some food for thought ...
Put your super-duper synthetic engine oil in your tranny or rears instead of tranny lube and see how long it lasts. I bet it does not make it 200k miles without some serious wear issues. -- What would that tell you?
RE: How much gear lube to add? - simon999 - 07-06-2016
It would be interesting too see how the oil sample looks gear oil in the engine