Best Grease/Oil for.....
 

What is the best grease or oil to use in a Maxx tranny? (3906 Maxx) I just want something to keep thing spinning smoothly. Suggestions? Greases/Oils I should not use in the tranny?

I honestly wouldn't bother. It has been done, but there are reliable greaseless setups. I just don't like the mess.

Yeah I saw on TheToyz forum how well that MooSlick stuff from CowRC works, its amazing for bearings, just not sure how well it would work in a tranny if at all. Also saw on the idiot forums that a couple people were using this grease in their Maxx trannys called Gorilla Snot Grease (I think thats what it was called? :neutral:). Has anyone had decent results with just putting some think shock oil in their tranny?

Best is either gorrilla snawt or moly

I am going to use bearing grease or white lithium grease...just depends on which I see first on my bench. It does make a mess, but it does provide less friction

Heat kills plastic gears. I like to use synthetic wheel bearing grease...

PS you only need a little don't pack it...

For the guys who said grease, I have a question for you.

Would any of you consider putting grease in a manual 1:1 transmission? How about a motorcycle gearbox?

I posted a few times that the best I've found is oil treatment, it can be any brand, STP, Coastal, doesn't matter. A 3906 or 3905 trans needs less than one ounce. It has high vicosity but still far less drag than grease.

And the biggest reason is it stays where it needs to be, not flung to the outside where it becomes a particle collector. And I must disagree with you paralyzed, about running dry, I think that is a huge mistake. Especially with the power in even a mild BL setup, this is suicide and will contribute more drag than even grease would.

I got a bottle of Coastal brand oil treatment at a local store for about 1.79, and the bottle will be enough for many trans and diff rebuilds. In the newer sealed diff cups it is also far superior to grease, and willl give a tiny bit of limited slip effect, but again it STAYS where it needs to be.

You racers need to try this, in the event you don't like it you can put the rest of the bottle in your lawnmower.....

Krawlin- " just putting some think shock oil in their tranny? "

That would actually be ok, unless it's silicone. Silicone is good for lubricating plastic on plastic and not used as a high load lubricant.

Petroleum is good for plastic/plastic, plastic/metal and metal/metal.

I have fill/drain holes in both my diff housings and the top of my trans, which allows me to assemble all of the above dry. I use a small syringe to fill, no better way to avoid the mess like paralyzed seems to not like :lol:

Ha! Good stuff. I've just never seen a failure of the tranny gears because of heat, but it would definitely make a more efficient drivetrain. I do like the analogy to 1:1 trannys. I would use the oil treatment on the ring/pinion in the diff housing, but im going to stick to silicone in the diff cups, for tunability.

So I assume that you allow the lower/output gear in the tranny run in the oil treatment, and it is drawn up onto the other gears. Seems like a good idea, IIRC Sike did this with his 3906 tranny when he had issues with the gears melting. He used lucas oil stabilizer, not sure if that is the same thing you are refering to. With rubber sealed bearings and a little rtv around the case halves it should stay in.

My mute's gearbox was dry and had a lot of miles on it when I got it. It was full of white plastic dust when I pulled it apart the first time. The issue in my exp is not heat, rather a bunch of added friction due to the dust becoming an abrasive that gets between gears meshing, etc. obviously. And that will lead to the plastic heating up and becoming gummy on top of the dust floating around, I imagine run hard enough you could weld the plastic gears together...

Linc, the viscosity is pretty close to 90 wt, but oil treatment sticks to everything regardless of centrifugal force, much more tenacious than regular 90 wt, so the trick is to use as little as possible. It will purge out the bearing holes if you overfill it, use only enough to get about halfway between the bottom of the trans or diff case and the lowest bearing. As you said it is self recirculating and won't need to be changed for a very long time.

Grease normally is used in simple pivoting mechanisms that are low speed,
like a hinge...

Silicone is a decent metal to metal lube, but has a weak and thin boundary layer, I have seen it not work more than work in certain applications. I understand the need for tuneability in diffs, and silicone is the only way to do that, but you may still run oil treatment on the ring gear/ pinion no problem.

Like I said guys, less than $2 bucks, I think I make a pretty good argument:yes:

Edit, linc it is thick enough it won't seep but just a bit damp around my plastic 3906 trans halves, no need to seal anything!

Just so we're clear-

Ive always want to experiment with a sealed emaxx tranny with a hole on the top and a hole on the bottom of the tranny with rubber stoppers and be able to run lightweight shockoil for the least amount of resistance.

Not the best pics, but here is the 10-32 setscrew on the top of the front half
of the trans, and the bottom of the rear diff with a 10-32 button head screw.