Thickening silicone diff fluid

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i got about 20 bottles of 1000/3000/4000/5000/7000 fluid and i won't use them because my nitro diffs will leak soon or later, from now on i will only use a thick diff fluid and i'm ok with the diff being locked or nearly locked.
i was reading that adding a sliced up silicone earplug will work is there any other thickening options.

 

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I googled this question.
"how to make silicone fluid thicker"

To make silicone fluid or sealant thicker, you can add a thixotropic agent (like Thi-Vex), which is designed to make silicone brushable for mold-making. Alternatively, commonDIY methods include adding fillers like cornstarch or fumed silica (Aerosil) to reach a paste consistency.

Yeah cornstarch method sounds like a cheap way.

 

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I restored my XTM Mammoth about 8 months ago and put it on the shelf and now she is off the shelf and plan to give her first start tomorrow and there was a good size pool of silicone diff fluid on the chassis and i put in new diff o-rings & gasket while building and it still leaked i believe i used 30-60k diff fluid i'm still starting her tomorrow and then i'll remove the diffs and put in some very thick fluid to stop the leaks.

 

[CertifiedMike]

I guess my question is, where is the fluid leaking from? Is the gasket missing, is it not seating correctly, orings junk???
Is there a way to correct the leaks without making each of your diffs a locker???

I never tried to thicken silicone. Never knew you could add stuff... I'm curious to hear how the cornstarch works out.

 

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where is the fluid leaking from? Is the gasket missing, is it not seating correctly, orings junk???

i did say,

i put in new diff o-rings & gasket while building and it still leaked

I'm buying some 250k-300k diff fluid in the mean time and use that when it arrives, i can figure out later what to do with the lower viscosity diff fluids i have.

 

[hood52]

Silicone ear plugs is common in the ctr diff, for bashers. Have you tried lightly sanding down your diff, to make sure it's flat? When you tighten your diff are using doing it evenly in a crisscross pattern? That can make a difference.

 

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When you tighten your diff are using doing it evenly in a crisscross pattern? That can make a difference.

yeah i do like to think i build my rc diffs good and this mammoths is no different and i'm not sure if the front is leaking as well i can't seeing any diff fluid leaking so maybe the front is ok.
i will remove the rear diff to check where it's leaking and put in some thick fluid.
I think the best way to make my 1000/3000/4000/5000/7000 fluid thicker is to mix it with 500k and with the right ratio mix i can have a container load of 150k fluid and that will be thick enough to prevent leaks
I got 2 full bottles of 500k that i don't need so i'll blend them.

 

[HPIguy]

I guess my question is, where is the fluid leaking from? Is the gasket missing, is it not seating correctly, orings junk???
Is there a way to correct the leaks without making each of your diffs a locker???

^^THIS! Figure out why the diffs are leaking and fix that rather than band aid it with fluid so thick it won't leak out. If you're shocks leaked with 30wt oil, would you run 300k weight or fix your shocks?

 

[CertifiedMike]

i did say,



I'm buying some 250k-300k diff fluid in the mean time and use that when it arrives, i can figure out later what to do with the lower viscosity diff fluids i have.

If you are sure the gaskets are good, orings fit, not twisted... I would suspect unflat surface, possibly cracked housing or wear that is letting something get by.

Have you tried to use a gasket sealant, maybe not permanantly, but to see if it fixes the issue?

Seems odd.

I think even putting mega thick oil would still eventually leak out. I have not tried this though, just thinking.

Most of my old cars use grease in the diffs still. Lol!

Arrma trucks are not leaking after a refil.

I know on old 1:1 engines, synthetic oils tend to leak where conventional dinosaur juice did not. You may be on to something. I'm curious to see.

 

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f you are sure the gaskets are good, orings fit, not twisted... I would suspect unflat surface, possibly cracked housing or wear that is letting something get by.

I doubt it but i will see when i remove the rear diff, the front diff looks to be leaking as well.

Have you tried to use a gasket sealant, maybe not permanantly, but to see if it fixes the issue?

No.

I think even putting mega thick oil would still eventually leak out. I have not tried this though, just thinking.

Iv'e had a minor leaking diff before and a thicker fluid stopped it.

Before i remove the diffs i started her and the engine does have really good compression, the fuel tank is huge.
I still have her on a slightly rich tune.

 

[WickedFog]

That diff housing looks like it's been pretty well used. Maybe grab a new housing if you can. Sand the faces lightly with some 800 grit or so on a nice and hard, flat surface to make sure they're flat. Injection molding doesn't yield a perfectly flat surface. The parts shrink and deform slightly when released from the mold.

Machinist's trick.. use a figure 8 pattern when sanding. It will keep you from sanding your faces like a mound. Low on the edges and high in the middle.

 

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The XTM diffs leak because they are crap even when they are new, use at least the recommended 100k.
Quote from the manual,
Adding heavier silicone oil will tighten the differentials and adding lighter silicone oil will loosen the differentials. If your truck feels
loose during turns, you can tighten the front differential or loosen the rear differential. If your truck is pushing during turns, you can
loosen the front differential or tighten the rear differential. We recommend using silicone oil weights between 30,000 (30K) and 100,000
(100K).

 

[CertifiedMike]

I doubt it but i will see when i remove the rear diff, the front diff looks to be leaking as well.


No.


Iv'e had a minor leaking diff before and a thicker fluid stopped it.

Before i remove the diffs i started her and the engine does have really good compression, the fuel tank is huge.
I still have her on a slightly rich tune.

I these are junk housings from the factory, sanding faces, gasket maker/sealer might help like @WickedFog said.
I know lots of ppl run super thick oils but 100k, 500k... Just seem super excessive to me.

I'm sure theres a mix between non-locked diffs and not leaking diffs.


That motor sounds so good!!! A little rich maybe but smoke doesn't look excessive.

I think its running pretty great! Nice!!!

 

[WickedFog]

Oh, that's one with an o-ring. Not much you can do there by sanding really.

What I would suggest is don't over torque the screws. It will warp the plastic ever so slightly and push the lip around the o-ring in the cover outward at the screws and cause the o-ring to fail. O-rings require some tight tolerances usually. So any deformation with the screws will have it leaking.

And yeah, put the correct fluid in it.

 

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XTM claim that the diffs can use either grease or silicone fluid lol...they are really just a grease diff.
I haven't taken the diff out yet and i already know the leak is at the large diff cup o-ring.

quote from the manual,
The Mammoth ST Nitro Stadium Truck features front and rear gear differentials that each feature o-ring seals and cup-style housings. Both
differentials are packed with differential grease that is good for most driving conditions.
You can make fine-tuned adjustments to each differential by removing the differentials from the chassis, opening them up and replacing
the grease already inside the differentials with silicone differential oil

 

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I bought the XTM mammoth and the GV Dominator from the same seller and restored them at the same time 8 months ago and the Dominator has no leaks it's a bevel diff.
I haven't started the Dominator since being built and it's happening today.

Dominator diff diagram

 

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she's o.k

 

[CertifiedMike]

I bought the XTM mammoth and the GV Dominator from the same seller and restored them at the same time 8 months ago and the Dominator has no leaks it's a bevel diff.
I haven't started the Dominator since being built and it's happening today.

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Dominator diff diagram
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This is the design of diff I thought you were dealing with. Seems like using a gasket is a better design.

Can you use this type of diff in the leaking buggy?

Sounds like it runs strong!