I just talked to the guy responsible for tribology and oil here at GM Powertrains. He stated that the GM EOS has not changed but the name has. It is called assembly lube now as an effort to get around the EPA regs. So this should put to rest the thought that the name change came along with a formula change.
Bill

Thats great to here ! Nice to see GM is smart enough to play the game instead of just caving in. Anybody have info on a part # yet ?

Try 88862586

I think the size of the bottle is the difference in Part numbers. The bottle I got was 16 ozs and was called assembly lube and was Part#1052367 ( I think same as old P/N) and the larger is part #88862586.
Bill

OK
http://www.gmpartsdirect.com/results.cfm?singlepart=1&partnumber=1052367

BILL/FYI,the gm eos has been called assembly lube for a few yrs so the "assembly lube statement" is not new to this latest version of gm eos.

I have 2 cases of the old/discontinued GM EOS in black container & the AC DELCO EOS in the white container which are both marketed as ASSEMBLY LUBE on the labels in my garage so i know thats the case.

Maybe gm just dropped the GM EOS statement and left the " ASSEMBLY LUBE " statement on the label & most importantly left the ZDDP formula the same as the older gen GM EOS

Again i would not use this newest/latest version of gm assembly lube for new cam breakin untill it's tested for zddp content to ensure it's still ok showing good zddp lvls IMHO.

Scott

I have been using Shell Rotella 15W-40. It is definitely good to see that GM did not discontinue EOS.

We used to dump a whole bottle of eos in at every oil change

When dad and my grandfather and uncle worked at GM they were REQUIRED to use eos when rebuilding an engine. They claim is it also leaves a glaze on the cylinders that the GM engine rebuilders said over the years

We have had excellent luck out of eos,we used to bath the cam, lifters, timing chain, gears, pushrods, roller rockers, valve springs, bearings and all in a long bucket that we have and we kept a lid for it so it was always clean. We now use childs and albert lube bute everything is roller now although we did use eos on roller cam and lifters etc too

Butch,just wondering what you meant by " They claim it also leaves a glaze on the cylinders that the GM engine rebuilders said over the years",doesnt mkake snece to me????

Are you saying the GM engineers stated GM EOS left some kind of glaze on the cylenders and if yes what kinds of glaze was it and did they think it was good or bad?????

Thanks...Scott

I was told also that the EOS has been using the assembly lube name for sometime. This was after my first post. The guy I spoke to is responsible for GM oil specs. So unless the manufacturer is not making this stuff to spec it should be the same. I will take his word for the zddp levels but I think SWEATON is right about the assembly lube name.
Bill

I just took a look at the bottle I bought. It has "GM EOS" and " Assembly Lube" on it. I am now wondering if they changed the name at all.

Well since the guy from GM didnt know what the heck was going on with the totle on the EOS bottles i would take anything else he states as a grain of salt .

Again,the EOS for GM & AC DELCO which were the same additives sold under 2 different pt#'s & divisions in GM both stated they were ASSEMBLY LUBE on the containers which i bought over the past couple yrs so the guy from GM is incorrect for sure.

So with that said the guy from GM could be wrong about the new assembly lube thats just been re-released which could maybe not be the same formula as the older discontinued EOS version,thats why i stated the new version of ASSEMBLY LUBE needs to be tested to ensure the ZDDP lvls are good.

Scott

Again i would not use this newest/latest version of gm assembly lube for new cam breakin untill it's tested for zddp content to ensure it's still ok showing good zddp lvls IMHO.

Scott

BINGO! As Scott's said several time already - I doubt anything you hear from "someone" at GM is telling you anything other than what they may have "heard", not "known". Testing the stuff is the only way to know.

Thanks guys for the part # and just to clarify the part # for quart bottle is 88862586

The guy from GM didnt say anything about the title. I was told that they used the title "assembly lube", for a couple years, by someone else. after talking to the guy about the formula. Unless someone has another option I will be using the EOS. If I cannot trust the guy responsible for the formula then I have no option and all who have been using this are screwed. I dont buy it. I contacted the place I bought it form and was told that the bottle has been in their inventory for almost a year. So I will fire my engine with it and let you guys know what happens.
Bill

I have a couple of questions about EOS. Has anyone had any negative results from running EOS during oil changes. I'm talking to the people who have been using it for awhile.

Second, do you notice a change in how your motor runs with it? I swear that when I add some to my oil is a tad more sluggish. Does it mess with the other friction modifiers in the oil? Maybe I'm just crazy,(probably am) but just had to ask. Not knocking the product in anyway.

James,when i ran a full pint of EOS in my motor with a mild hyd flat tappet cam the valvetrain runs dead quiet where it would make a little noise when hot you could only hear with hood up,the oil pressure inc approx 2lbs when hot,and the idle rpm inc 100-150rpm too.

This is in a motor with approx 3,500 miles since a complete rebuild .

Scott

Scott, With the increase in oil pressure does it thicken the oil?

Yes,just A Smidge,the Eos Had A 50wt Base Stock Oil .