What happens when you forget to shim the diff main gear 4S/3S

[jondilly1974]

Somehow I forgot the shim on the main gear side when I last rebuilt my K4S and this was the result

 

[Porschetech🇬🇪]

Somehow I forgot the shim on the main gear side when I last rebuilt my K4S and this was the result

View attachment 73214

Yikes!!

blame it on the alcohol. ?

 

[suchtragedy]

I bet that sounded dreadful

 

[jondilly1974]

I bet that sounded dreadful

It was just a few seconds and then all I had was FWD

 

[Porschetech🇬🇪]

It was just a few seconds and then all I had was FWD

Plastic has that effect ?

 

[suchtragedy]

Maybe now you can make a diff replacement video for the community ?. On the next episode of JDs garage...

 

[jondilly1974]

Maybe now you can make a diff replacement video for the community ?. On the next episode of JDs garage...

Dang you could have told me that an hour ago. Now I gotta ruin another diff on video this time ?

 

[suchtragedy]

Dang you could have told me that an hour ago. Now I gotta ruin another diff on video this time ?

When there's a will there's a way my friend ?

 

[Camaroboy383]

ugh.. that sucks..good thing they are cheap as dirt, and im sure you have a few on hand like i do.. ??? ive only ever had to do one on the typhon, but always have spares...? the strangest thing was the yoke setup in my typhon was super tight on the mesh when i got it.. after it died, the new ring and pinion felt just as tight and pretty much bound it was meshed so tight.. i removed the shim and it was like spot on.. still even a little tight.. these yokes are all over the place on qc, too tight, too loose, flip of the coin...?

 

[jondilly1974]

ugh.. that sucks..good thing they are cheap as dirt, and im sure you have a few on hand like i do.. ??? ive only ever had to do one on the typhon, but always have spares...? the strangest thing was the yoke setup in my typhon was super tight on the mesh when i got it.. after it died, the new ring and pinion felt just as tight and pretty much bound it was meshed so tight.. i removed the shim and it was like spot on.. still even a little tight.. these yokes are all over the place on qc, too tight, too loose, flip of the coin...?

I find the diff cup seal will squeeze out if you tighten the screws on the main gear too hard and it runs on the input gear face. Also, if you crank the yoke screws all the way snug, it will bind too.

 

[Porschetech🇬🇪]

Damned if you do and damned if you don’t ?

 

[fpvmiller]

I know it's pricey (cause I checked the prices) but I am wondering if the hot racing aluminum/steel setup would help to mitigate this?

 

[jondilly1974]

I know it's pricey (cause I checked the prices) but I am wondering if the hot racing aluminum/steel setup would help to mitigate this?

I’m sure it would. Also, a 0.5mm shim does the job too ??‍??

 

[suchtragedy]

So while we're on the subject of these diffs can someone tell me the purpose of the hot racing aluminum yolk is? Like what problem does it solve supposedly or is it just one of those "aluminum is stronger so it's better" things?

 

[Camaroboy383]

So while we're on the subject of these diffs can someone tell me the purpose of the hot racing aluminum yolk is? Like what problem does it solve supposedly or is it just one of those "aluminum is stronger so it's better" things?

the plastic yields under torque (twists) can kill the ring and pinion.. ? and they don't distort when you tighten them up..

 

[jondilly1974]

So while we're on the subject of these diffs can someone tell me the purpose of the hot racing aluminum yolk is? Like what problem does it solve supposedly or is it just one of those "aluminum is stronger so it's better" things?

I bought them a long time ago and don’t recall what prompted me to buy them, but what most would gain is a hot bearing won’t melt aluminum. Some noobs run stock bearings way beyond their lifespan.

 

[suchtragedy]

Got it.. so basically a good idea once you go big power and/or want to be lazy about regular maintenance ?

 

[fpvmiller]

Got it.. so basically a good idea once you go big power and/or want to be lazy about regular maintenance ?

I'm falling into the latter hahahaha I dreaded tearing down f/r diffs on my race rigs. With my granite/kr6s I'm trying to just charge and rip. My granite is just snowballing into a fun project right now.

 

[suchtragedy]

I'm falling into the latter hahahaha I dreaded tearing down f/r diffs on my race rigs. With my granite/kr6s I'm trying to just charge and rip. My granite is just snowballing into a fun project right now.

You are the RC version of Pimp My Ride ?. I'm greatly enjoying your journey, I get to see what cool stuff works/doesn't work without hurting my own wallet first ?

 

[MrTitanium]

Even with the right shimming, there is only so much these plastic gears can take before they give up the ghost. It’s a real shame that Arrma hasn’t yet released their CNC steel gear set (AR310855 and AR310856) as I was really happy when I first saw them on their site. Now, part numbers can no longer be found.

With this being said, I ordered the HR diff gears, diff cups and yokes. A small fortune, to be honest. All that’s left is doing a dry assembly and installation. There’s a fellow on YouTube who reviewed this assembly and it looks promising.