hross14

Now, before i start this thread on this gear oil--can we lay down some ground rules:

1. Not what you think should be stated but what FACTS you know.

2. Anybody or company running it and have analysis?

3. Lets make this technical and not the usual i wanna one-up the other post.

4. Point here is to learn and whether or not this oil's reputation preceeds it?

5. As far as i know--we dont have brass synchros so GL-5 is not a problem for 3rd gen trannies and most of use dont use Clutch type LSDs'

6. Pros and Cons are warrantied


Here is what i know so far.. http://www.bobistheoilguy.com/gearoiltest.htm

Stuff sounds like a quality product--what do you know about it?

hross14

Bumpity

mkgarrison5

its a top notch oil... as for the tranny you may want to research more but for the diffies and engine. fantastic oil my man

crolison

I wouldn't use gl-5 in our trannies ,or tcase. I have heard of using gl-5 and having some problems with shifting, and i think our manuals say go for gl-4. I am running gl-4 redline mt90 and its great.

I wanna try the schaeffers stuff in my diffs now I usually end up changing my rear diff fluid every 6ish months, and my front diff automatically cycles through fluid. So If i can find this stuff local I'll run it. I am using Valvoline synth 80-90 in my rear diff, and A mixture of 70-90 mobil 1 and Valvoline synth 80-90 in my front.

hross14

Ok--so we can run the GL-5 in our trannies but it has friction modifiers right--that make out trannies shift different?

I will look at Schaeffers and see if they have a GL-4

mkgarrison5

you will have better luck running the GL4 in the tranny. i am sure they make it.. again thats a great brand of oil.

hross14

bump--

hross14

Something i have learned recently about oil and the new formulation coming out is that they will have less ZDDP (the spelling is crazy so...). If what i read if correct--this is the stuff that makes oil slippery and fills in micro surface scratches and wear.

They are doing this so catalatic converters last longer---doesnt make sense though--$200-500 cat versus a $2-3k engine job????

I wonder who will carry the oil that will contain the "right" stuff? Doesnt shell rotella and some of the other diesel oils have this in it. That is what separates it from regular motor oils?

Bottom line--i would rather replace the cat than my motor

MadCityRich

This issue tends to affect motors with flat tappets. Flat tappets tend to be found on older muscle cars, though my mid '80s BMWs had them. You can get hydraulic flat tappets, too, though I'm only familiar with solid tappets. Tappets are the part of the valve rocker arm that contacts the valve stem. The issue is that with flat tappet systems, the pressure between the valve stem and tappet is extremely high. In the flat tappet case, you always had to have a bit of space adjusted to allow for metal expansion. The ZDDP did a good job of dealing with the forces as the tappet and valve stem meet. For whatever reason, ZDDP maintained the oil in this extreme pressure environment. I have no idea if the 3.4 liter engine uses flat hydraulic tappets or not.

ZDDP contains phosphorus. Phosphorus is associated with fouling catalytic converters. The reduction in ZDDP is due to the emissions concern raised by failing catalytic converters. Whether it's a major problem or not, I'm not convinced, but the oil manufacturers have been removing phosphorus in an attempt to meet the emissions regulations. In a good operating engine, there's probably no issue with catalytic converter failure as the oil passing into the exhaust stream will be minor. However, most emissions regulations address the gross polluters, who spoil it for the rest of us, and who are often passing much more oil into the exhaust stream (burnt or otherwise). Whatever the case, ZDDP has been decreasing, though many modern engines don't have flat tappets anymore.

ZDDP will have no major benefit in a gear oil. My opinion is that the forces just don't reach the levels like we'd see with flat tappets. So ZDDP in gear oil seems like a non-issue. I haven't seen research one way or another on ZDDP in gear oil, but there are some good online articles related to ZDDP and flat tappets.

Hope this helps.

MadCityRich

hross14

Man--good post!!!

It is the Moly we are concerned about in Gear Oil--