Best Grease / Lube for Tamiya 1985 Bruiser Tranny

[steponit! 23]

Hi Good People !

May I know what type of grease / lube do you Good People use for the 'Tamiya 1985 Bruiser 3 speed Tranny'? Is 'marine grease' any good? It's waterproof, right? How about the 'Bendix Ceramic High Performance Synthetic Lubricant' (or similar) which is used for 1:1 real car brake pads...it's for "metal to metal" surfaces...gears are made from metal, right?

Your thoughts and advices is highly appreciated !!

Thank You, Good People !

p.s. I'm planning to do a "full service" (well, sort of!) on the tranny guided by Mr. Koping Hu's manual! Wish me luck !!

[c64orinoco 667]

I think the theory is molybdenum grease for metal gears, ceramic grease for plastic.

[Fuijo 880]

I was under the impression that grease was not necessarily a good idea as it might make the gearchange a bit sluggish. Tamiya recommends light oil, but I'm going to use graphite powder on my 4x4 pickup so I don't have to use silicon sealant on the outside of the gearbox.

[Exit13 673]

I use Permatex (auto parts store) anti seize. I believe it to be the same material as one type offer by Tamiya at a fraction of the price.  I put it in all my new and vintage gear boxes. 

[87lc2 2666]

I typically use moly on metal gears, but I believe the 3-speed is a special case.  I only have the HG version, but I coated the transmission gears with a light coating of basic motor oil and it has performed flawlessly and quietly since day 1 (it was the kit version).  Shifts great as well.   Pretty sure I read that on TC at some point, just a light coating of oil rather than grease in these 3-speeds. 

[steponit! 23]

Thanks so much for the awesome info, Good People ! Really appreciate it !!

Have a nice day, yo' all !!

[SuperChamp82 743]

+1 re @Fuijo

V light oil if the box is sealed outside - although it almost always leaks / hence the rubber plug to top up …

Graphite far better imo - even if not original 👍

[WillyChang 1814]

Graphite & other dry lubes aren’t going to reach the bushings. 

 

My trucks don’t get run much; majority of time on shelf duty. Whilst reassembling gearbox I lubed the bushings, forks & gearteeth with a thick 80-110wt hypoid diff lube. 

they’ve stayed wet; doesn’t drip to bottom of gearcase
 

Phil’s Tenacious might be even better. 

[SupraChrgd82 1425]

Use Tamiya grease.  Granted, there are a lot of effective lubes on the market each with it's own unique attribute.  But it is always suggested to use the manufacturer's recommended lube, in part due to some ingredients causing the plastic materials to degrade.  Several members here have experienced damaged components from using different lubes, thread-locks and adhesives. 

Graphite, as mentioned above is inert if used in a dry form (no carriers or propellants) and will not damage plastics.

 

[steponit! 23]

Thanks for sharing SuperChamp82, WiilyChang and SupraChrg82 !!

Really appreciate it! 

[SuperChamp82 743]

On 4/15/2022 at 12:12 PM, WillyChang said:

Graphite & other dry lubes aren’t going to reach the bushings.

True if you just blast it into the assembled box @WillyChang but you go on to (rightly) talk about sorting this during reassembly ?

That’s when any lube works best - including dry 👍

[Juggular 4964]

While both dry and wet types could work well, I prefer wet-type in a sealed gearbox. 

I use graphite on locks and dog bones for temporary protection because it does not attract dirt (no cohesion). But grease is useful because of cohesion. Grease/liquid tends to bead and stick together.  We see the evidence of water sticking to corners in every shower stall/tub.  The same cohesion applies to grease.  And that's good thing for the bushings/bearings/teeth of gears. 

I often get a vintage car like the frog. And the thing would still have sticky grease in the bushings, applied Godknows when.  Somehow I don't think I can expect the same kind of of protection from graphite. Even though I believe graphite itself is superior molecule as a lubricant, the problem is having no cohesion. You need millions of molecules to stick together.  Graphite dust is like dust in the wind.  That is why I use graphite only "temporarily" where I don't want it sticky.  If you put grease on a dog bone, even dirt would stick (not a good thing on the outside).  If you put graphite on it, you know it only protects for like one run. Inside the gearbox is different, obviously. 

I'm thinking mortar and pestle. Like graphite molecules, pills/grains don't want to go between mortal and pestle. But they are forced by the walls of mortar & gravity. If you crush pills on a flat table, things would go flying.  Same with gears. Gears don't have tight walls/gravity that focus graphite between teeth.  Gears turn, and centrifugal force tends to fling everything out. Not only that, teeth grind with each other to shake things loose. I'm afraid dry molecules might not stick around for too long. 

Things caught between bushings and shafts, also would want to get squeezed out. There is microscopic gap between any bushing and shaft. The shaft rattles around inside the bushing. Because of this, we see grease getting squeezed out, but still some remains for decades because grease is sticky. As it gets pushed out on one side, cohesion pulls it back together on the other side. In that sense, grease is like chewing gum. Your teeth squeezes it, but it won't go flying out because it's sticky and cohesive.  Since gears don't have saliva, I'm afraid graphite would come out of teeth of gears and settle on the walls of the gearbox.  There, it doesn't have to fight to stick on to something that wants to brush it out.  This is why we don't see graphite engine oil (though they sell additives). We only see it on bicycle chains where not attracting dirt is a plus.  

Molybdenum is a good lube when it comes to metal gears.  Aside from the stickiness of the binder of the lube itself, the molybdenum molecule is like a charged molecule.  It wants to bind to metal parts and coats the surface.   

==============================

Now, having said that... spray-on graphite? 

I want to try it.  The resistance should be very low.  My only concern is that I don't know how long it would stay coated.  If it does, why not?  If I get a bottle, I want to use it on A-arm hinges to see how long it lasts.  

If it doesn't stick around for too long, I'd prefer moly.  At the same time, many moly lubes are made sticky enough to withstand 10,000 pounds of pressure. Way too sticky a small 1/10th scale truck.  So if I take apart my 3 speed?  I have a feeling that I'd use tried and true Teflon grease. (like Super-Lube. An 85g tube would last 50 builds). 

 

[steponit! 23]

Great info, Juggular ! Thanks !!

[spankrjs 77]

The problem with the vintage 3 speed gear boxes is the "center section" of the transmission assembly. You can easily replace all of the bushings with ball bearings in the transmission easily, except for the center section. The way the shafts/gears/bushings are assembled in this center section does not lend itself to easy disassembly/reassembly to install ball bearings. It can be done, I have successfully completed this task, but not for the faint of heart. I had pictures/step by step instructions posted up on the "scale4x4.org" website, but all if that is gone now.

Anyway, with bushings supporting these center shafts/gears you really need a liquid lubricant to wick in between these steel shafts/bronze bushings. Really no way to get grease in these spots.

I will have to look on my old laptop and see if I still have all the pictures of the work involved with installing ball bearings in this center section and post them up.

[steponit! 23]

Hi spankrjs !

Thanks for the info and hope you'll find those pictures !!

[spankrjs 77]

On 4/24/2022 at 12:09 AM, steponit! said:

Hi spankrjs !

Thanks for the info and hope you'll find those pictures !!

Started a new thread:

 

[steponit! 23]

Cool info, spankrjs ! Really appreciate it !!

[JeffSpicoli 1363]

Just pour some mobil 1 synthetic in there.