Topic: Message #517546

[KDXSR5]

Thanks for replying Duffil! Yes that is where I first heard of the GL-5 being to slick.

Thanks for your reply as well Glen! Well, I am trying to decide between a GL-4 or GL-5 synthetic transmission and transfercase fluid. I can't find anything in town besides Mobil 1, and I am not going to pay that much for stuff that I have heard is not that good. So I pretty much decided on Amsoil, after reading a post from... I don't remember, I will try to find it, saying that Amsoil is the best synthetic lube. So I have been trying to decide between these two:

http://www.amsoil.com/StoreFront/mtg.aspx

^ GL-4 Stuff VS GL-5 Stuff v

http://www.amsoil.com/storefront/svg.aspx

I just don't know which one to go with, because I don't know which one would be best for my transmission and transfercase. What do you reccomend?


EDIT: Ok, here is some stuff from BigMike on synthetics (for engine oil, but I would guess same applies to any lube):

My claim is pretty one minded and heres why. About 2 years ago I was at a Denny's cramming for a test and these guys behind me had a hardcore discusion about chemistry/oil formulas and what not. I was listening in and I think they must have noticed me as the one guy nearest introducted himself and asked what I was studying. I told him what my major was and he was curious to see how much I knew about engines. After quizzing me about oils and lubrications he said that I was a good kid and he gave me his card and told me to meet him the next day.

It turns out that these two guys are on a leading oil research team who helped design oils for NASA and others. They are working on an oil that when it combusts it molecularly turns into some kind of detergent rather then a contamanent and it will also lower emissions by consuming unburned particulates; like I said crazy chemistry talk of which I only understood about 20%

So as for my one sided mind, to be perfectly honest, I've never even used Amsoil, but both of these guys swear by it, were distributing it, gave me a bunch of fliers, yadda yadda yadda. They told me that Amsoil is the inventor of Synthetic oil, like back in the 60's.

I asked them how they felt about the other "over the counter" oils and he drew me a graph of his experience with testing oils. He told me that the order he would use syn oil is as follows: 100% is Amsoil, 80% is Pennzoil, and then wwaayy down at like 40% he recommended Vavoline, then Castrol, and even further down like 10% he recommended Mobil One.

And that is strange because so many manufactures use Mobil One, like Mercedes, so I'm sure they have their own researchers, but maybe Mobil One has gotten better in the last couple of years because both of these guys HATE mobil one and they said its all a bunch of market hype.

About Blended oils, the guys told me to avoid them. Also they said to avoid MULTIWEIGHTS. But everyone uses multiweights ?? The guys told me that multiweight, like 10w-30 foam and do not last nearly as long as a single weight, like a straight 30. Also, my friend does Circle track racing and he told me that every car only uses single weight oils. I don't know any politics behind that but its another thing to look into I guess..

Anyways, yesterday I was at autozone, and I needed to change my oil, so I just went with some Synthetic oil despite my rear leaking main seal. I got some Pennzoil Syn Oil. I got the new Platinum oil and went with a 10w-30. I'll let you know if my leak gets worse.

Later
BigMike

It is from this thread: http://board.marlincrawler.com/index.php?topic=9685.0;highlight=amsoil+synthetic#quickreply


EDIT X 2: Found this:

We recommend 80/90 weight GL5 gear oil. Any brand as long as it is GL 5. This is the factory weight oil.
Synthetic [GL 6] is always the better choice.
Use the weight that is made for manual transmissio

Marlin

From this thread: http://board.marlincrawler.com/index.php?topic=3549.0;highlight=what+oil+synthetic#quickreply



This:

You should never use synthetic lube on anything brand new. Use mineral oil for at least 1,000 miles of stop and go driving before switching to synthetic.

In transmissions, synchros are these round brass rings that use friction to speed-match nearby gears and shafts before the gear change is actually made. This is how we can change gears with the clutch at speeds above about 5mph. Transmissions that are shifting hard either are badly worn out or are brand new and the synchros have yet to be "seated" or broken in. The "seat" by friction wearing down uneven surfaces between the mating brass synchros and the metal gear or shaft that it comes in contact with each time you move the shift handle. So with mineral oil, their is enough friction for the synchros to wear normally. Once they are worn in, then you can switch to synthetic. If you start out with synthetic, then its believed that the frictional properties of the synthetic lube is so efficient that the brass parts dont have any time to break in because its just too slippery.

So start out with 80-90 wt GL5 mineral oil for a while, and then once it starts shifting smoothly, maybe somewhere around 1,000 - 2,000 miles, then you can drain it and fill up with synthetic.

BigMike

From this thread: http://board.marlincrawler.com/index.php?topic=5637.0;highlight=what+oil+synthetic#quickreply

And this:

Use either Schaeffer's Synthetic Gear oil (http://www.schaefferoil.com/) or Red Line.

You can run Syn in a t/case regardless of its age, but if your transmission is under 2,000 miles old, then I would recommend using mineral oil until the syncros have seated properly.

Regards,
BigMike

From this thread: http://board.marlincrawler.com/index.php?topic=9276.0;highlight=what+oil+synthetic#quickreply


And lastly this:

Tranny and Tcase should be the same.

If your going Mineral Oil, then use any 80-90 Weight GL5 Gear oil.

If your going Synthetic, then any Syn Gear Oil is ok. We recommend the best oil in the world - AMSOIL (however we do not offer it) or Redline Gear Oil.

Regards,
BigMike

From this thread: http://board.marlincrawler.com/index.php?topic=2186.msg18492#quickreply







And that is all for now, I can find more if needed. Maybe I should go with the GL-5?