Granite Broke my First Diff Input Gear

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Even pulling all the internal gears out it is very easy to reassemble. It can only go back together one way. If the gasket is a hassle you can always reuse the top from the old diff that already has a gasket.
 
Even pulling all the internal gears out it is very easy to reassemble. It can only go back together one way. If the gasket is a hassle you can always reuse the top from the old diff that already has a gasket.
I’m just lazy…🥴
 
I doubt that mate. You're the guy who files down spur gear teeth to ensure the mesh is 100% at every turn. 😎
😂Yeah you got me. I don’t like all the little parts. I just haven’t messed with them enough to be comfortable yet.
 
😂Yeah you got me. I don’t like all the little parts. I just haven’t messed with them enough to be comfortable yet.

I totally get that. I can't really believe how much I dive in these days and pull sh*t apart. My first diff maintenance was on a WLtoys 144001 and I was petrified. Trust me, I'm not known for working on things or fixing things. My friends are astounded by how confidently I wrench my rigs. 'Old dog, new tricks ' 😉
 
I totally get that. I can't really believe how much I dive in these days and pull sh*t apart. My first diff maintenance was on a WLtoys 144001 and I was petrified. Trust me, I'm not known for working on things or fixing things. My friends are astounded by how confidently I wrench my rigs. 'Old dog, new tricks ' 😉
I have rebuilt many wiltoys 12428 diffs…But when I have way to much going on I get overwhelmed easy. When I get to this point I have to be careful about what I attempt or I’ll do a poop poor job. Right now it’s easier to throw an old diff in a box to mess with later and put a new one in that I picked up from Jennys.

I didn’t even want to learn a simple new car (mt10) after I got it. But I decided to when I realized I wanted to keep it and not return it. Team Associated’s warranty process is spectacular also, after I got through the process of submitting it properly that is. They warranted the entire Steering assembly, including servo, as well as the broken c-clip etc. And they did it the same day I submitted the claim and mailed the parts out an hour later! Can’t wait to receive them and get that little car back up and running lol. I have already shoo gooed the lid, put on some protective body skids and found a nice heat sink and fan in my extra parts for it. If the reason it drives so good is the center differential…then I am now a Center differential fan.

At least things are calming down. My step daughter is getting settled in even though she’s very delicate emotionally. My wife is doing extremely well and can finally start helping take basic care of herself. My foot…well it’s still all fiddlesticked up. I haven’t been able to rest it at all. I really need to get in to my orthopedic to look at it. It’s been nearly 2 weeks and it feels just as bad as it did on day one 🙄
 
Honestly ive been scared to change the diff oil but its really easy if you can take apart everything & actually change the input gear your capable of changing the diff oil trust you wont have to take the gears out just open put in oil thats it & I changed mine to 20k diff oil & you will see a huge difference & the yoke will just keep the rear solid I haven't stripped any gears since I installed it & I stripped 2 before
This might be a hard question to answer but what did changing to 20k oil do? How does it change how the truck runs?

If I’m not mistaken, 20k would be thicker than the stock oil? Does thicker add resistance to the gears?
 
I have rebuilt many wiltoys 12428 diffs…But when I have way to much going on I get overwhelmed easy. When I get to this point I have to be careful about what I attempt or I’ll do a poop poor job. Right now it’s easier to throw an old diff in a box to mess with later and put a new one in that I picked up from Jennys.

I didn’t even want to learn a simple new car (mt10) after I got it. But I decided to when I realized I wanted to keep it and not return it. Team Associated’s warranty process is spectacular also, after I got through the process of submitting it properly that is. They warranted the entire Steering assembly, including servo, as well as the broken c-clip etc. And they did it the same day I submitted the claim and mailed the parts out an hour later! Can’t wait to receive them and get that little car back up and running lol. I have already shoo gooed the lid, put on some protective body skids and found a nice heat sink and fan in my extra parts for it. If the reason it drives so good is the center differential…then I am now a Center differential fan.

At least things are calming down. My step daughter is getting settled in even though she’s very delicate emotionally. My wife is doing extremely well and can finally start helping take basic care of herself. My foot…well it’s still all fiddlesticked up. I haven’t been able to rest it at all. I really need to get in to my orthopedic to look at it. It’s been nearly 2 weeks and it feels just as bad as it did on day one 🙄

MT10 is my favorite RC. I have not had any steering issues just normal wear and tear. But TBH it still looks new. And I have given it plenty! But I did rip my Typhon yesterday and that rig is just FAST! It's my 'send it to the moon buggy' and it takes it!!!
 
MT10 is my favorite RC. I have not had any steering issues just normal wear and tear. But TBH it still looks new. And I have given it plenty! But I did rip my Typhon yesterday and that rig is just FAST! It's my 'send it to the moon buggy' and it takes it!!!
Yeah I love my typhon. Hardly driven it yet though really. I have belted mx28 STs on it and it freakin rips. I’m looking forward to getting the mt10 running again. I did enjoy it for a little while.
 
This might be a hard question to answer but what did changing to 20k oil do? How does it change how the truck runs?

If I’m not mistaken, 20k would be thicker than the stock oil? Does thicker add resistance to the gears?
Diff fluid weight changes the handling characteristics. Some say thicker diff does increase the chance of damage to the drivetrain because of more resistance. But 20k is not considered so heavy, and there are people running much heavier, so I can't say for sure whether or not it would affect durability.

The differentials allow the two front (or two rear) wheels to spin at different speeds. When you're turning, the inside wheel spins less than the outside wheel. More power goes to the wheel with less resistance (the outside wheel). Allowing the wheels to spin at different speeds enables a tight turning radius.

However, there are times this is undesirable. If one of your wheels has no traction, it will provide little resistance. Most of the power will get sent to this spinning wheel which of course is useless. Heavier diff fluid forces the two front (or two rear) wheels spin at closer to the same speed. So instead of sending all the power to the wheel with no traction, the opposite wheel also gets power.

So heavier diff oil can reduce excessive wheel spin and increase traction. This will help with straight line acceleration, especially on loose surfaces, since it won't waste as much power on wheels when they're slipping. It will also reduce excessive spinning/slipping during turns. But too heavy may decrease how tight the car can turn, since a certain amount of slip/spin is desirable. How much depends on your preference. https://escaperc.com/pages/about-differential-oil-setup.

I was running on very worn down tires at one point so my wheels were slipping too much. Changing from 10k to 20k both front and rear made a noticeable difference. I liked it. In general I like sliding around, but 20k made it controllable. Since then I've gotten new tires, traction was no longer a problem so I switched back to 10k.
 
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I had some time today build my diff now that all my parts came in.

However something is concerning me. When I hold the yoke and turn the input gear from the outside there is a lot of resistance. And this is WITH grease on the outside. Is that…normal? It concerned me so much that I even opened up the front of my truck to compare that diff and it’s doing it too.

I’m referring to spinning the input gear and it turning the large gear on the outside of the diff casing.

The photo is of my front diff. Although I doubt that matters.

Is the resistance normal?

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I'm not saying binding in the ring and pinion gear is normal but it's definitely not uncommon. I did a complete rebuild a couple of days ago, new input gear and diff case and there was a very small amount of binding. A small 'catch' each full revolution. I think the plastic yokes allow very little tolerance and are a major cause of diff issues.
 
I'm not saying binding in the ring and pinion gear is normal but it's definitely not uncommon. I did a complete rebuild a couple of days ago, new input gear and diff case and there was a very small amount of binding. A small 'catch' each full revolution. I think the plastic yokes allow very little tolerance and are a major cause of diff issues.
That's pretty much exactly what mine is doing. I realized my diff case gear had low teeth in some parts but luckily I had a spare and that's what I was using when I noticed the binding. The thing is the spare is not NEW. I inspected it best I could and the teeth look ok. Definitely better than my other one. At the point where it binds a bit, the teeth could be worn down a BIT but it could be my imagination.

I'm tempted to just get a new diff case now and have it on hand. I already have everything else to completely build a new diff.

I would need a bottle of oil. So do I go the stock 10k, or the 20k that seems to be the common "upgrade?"

I was just checking Amain where I get most of my stuff and they are out of Diff Fluid. Would something like 15K be worth a try? It seems most people go for the even numbers. 10k, 20k, etc. Any particular reason for that?
 
Yeah I love my typhon. Hardly driven it yet though really. I have belted mx28 STs on it and it freakin rips. I’m looking forward to getting the mt10 running again. I did enjoy it for a little while.
I just got kraton/mojave 6s shocks in for the typhon and yellow TA springs are on the way. I am also going to throw on a new set of mx28 MTs and tbone basher bumper just for fun 😃
 
I bought the metal ring and input gear for the back diff, since it's usually the rear that strips out first. It went together very well. I also upgraded to the HR motor mount. It is so much better built than the 3s blx mount. She thick. I also have the metal spur gear so I shouldn't have to worry about stripping gears for a while.

I think my next upgrade will be cvd shafts as the u joints keep popping out of the hubs. Or I'll just buy a couple extra composite driveshafts for when they wear out.

Mine popped out when I ran my Typhon on 4s. It can handle it as I have a 120 amp Max 10 esc. But I mainly run it on pavement and some grass. But only on pavement when it's on 4s.
 
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