New Willys Jeep owner

[DougL]

Here are some recent photos. fullsizeoutput_257a.jpg fullsizeoutput_2572.jpg fullsizeoutput_2578.jpg fullsizeoutput_2576.jpg fullsizeoutput_2574.jpg

[okiemark]

Looking good!

[bmorgil]

Doug, be sure when they fill that trans and case back up, they use the right lube. It MUST be for synchronized transmissions. No EP additives should be in it. It (EP additives) have a few bad effects on synchronizer's, especially brass ones. I cannot tell you how many times someone put standard 90wt or 140wt gear oil into a bronze synchronized transmission, only to complain that now it is miserable to shift. Once its in there for a while, it usually effects the synchro's for good.

First and foremost the common UN-spoken concept of the synchro, is not discussed in the "Lube" conversation. The synchro in the T90 is a brass cone clutch. As the shift collar is moved it engages the teeth on the synchro and the inside of the synchro (the cone) presses against the machined surface of the next gear, this pressure spins the next gear up to speed and the shift is "synchronized". Any EP additive impairs the pressure of the cone pressing against the gear to spin it up. This just screws up the shift.

Next is the incompatibility of EP additives and brass synchro's. Most EP additives are corrosive to brass. There is a You Tube Video out there that is not quite accurate so, be careful! There is however some pretty good stuff put out by the manufactures. As always, dropping a line to the Tech Department at your preferred supplier is the way to go if you want to be sure of what you are buying. If they can't answer your questions with fact, buy elsewhere.

I use Red Line MT90. I love it. Thin but still has a 90wt rating. In Older manual geared Muscle cars it is a fast shifting lube.

[DougL]

I'm on the Amsoil website and I don't find the MT90 you speak of. Is it possibly under a different name? I saw a "Severe Gear" 80W-90 that's synthetic, but no MT90. Can you provide me a Product Code from Amsoil? Thanks!

[bmorgil]

Whoops! Sorry about that. It's Red Line.

https://www.redlineoil.com/gear-oil-...-transmissions

[okiemark]

I am glad to learn about this. I had bought some 90wt to put in everything and sure enough it is EP or extreme pressure. Is there any reason not to use it in the differentials?

[bmorgil]

It MUST be used in the differentials. The gear design in the differential is different than the gears in the transmission. The differential gears are of a Hypoid design. Without getting into the design of Hypoid's, suffice it to say there is a significant amount of "sliding" as the gear teeth mesh. An EP of the best quality is required to keep it functioning. There is a tech document in the Tech Article section https://willysjeepforum.kaiserwillys...-0020-Dec-2015 that shows you just what will happen. This is a Heavy Axle document but the failure section is spot on for any Hypoid gear set.

Do not feel like you missed something. Since 1900, every service station had 1 bucket of gear lube and one pump. I exaggerate of course but, I can't tell you how many warranty issues are created by this. I did it myself as a 15 year old mechanic working at the SOHIO service station. You put it in the air, you pulled the plugs, you topped it all off with "Gear Lube".

There are surely many "Mechanics" who will tell you "I always did it this way, I never had any problems!" Unfortunately, they are not quite correct. I would have loved to invite them to a warranty failure tear down analysis many miles after they did their "Job".

[DougL]

It MUST be used in the differentials. The gear design in the differential is different than the gears in the transmission. The differential gears are of a Hypoid design. Without getting into the design of Hypoid's, suffice it to say there is a significant amount of "sliding" as the gear teeth mesh. An EP of the best quality is required to keep it functioning. There is a tech document in the Tech Article section https://willysjeepforum.kaiserwillys...-0020-Dec-2015 that shows you just what will happen. This is a Heavy Axle document but the failure section is spot on for any Hypoid gear set.

Do not feel like you missed something. Since 1900, every service station had 1 bucket of gear lube and one pump. I exaggerate of course but, I can't tell you how many warranty issues are created by this. I did it myself as a 15 year old mechanic working at the SOHIO service station. You put it in the air, you pulled the plugs, you topped it all off with "Gear Lube".

There are surely many "Mechanics" who will tell you "I always did it this way, I never had any problems!" Unfortunately, they are not quite correct. I would have loved to invite them to a warranty failure tear down analysis many miles after they did their "Job".

Good morning! Would it be ok to dump all the fluids (differential & transfer case) and replace them with the RedLine MT90?

[bmorgil]

Not the Differential. It needs the EP big time. Two different Lubes. In the trans no EP, in the Diff, EP.

[gmwillys]

It would be nice to be able to have a one size fits all, but it is very important to use the correct lube, as Bmorgil has stated.