Talion Sun Gear Blew Up - What To Do?

[JohnnyBLX185]

Hi all, this is my first post, but I've been using this forum as a very useful reference--so thanks everyone!

Today the sun gear on the left side of my rear blew up--Talion v4. Maybe because I was running a 20t pinion and Backflip tires on 6s? The sun gear ended up in 4 pieces and the pin was sheared off.

Anyway my question is do I rebuild the differential, just replace the whole differential (doesn't cost much more), or is there a stronger option than stock parts? I'm just don't know if this was a one off break, or if this is likely to happen again. If I rebuild, should I shim the differential differently--could that have lead to the breakage? Maybe buy a stronger differential case--though that did not seem to be the problem.

For what it's worth, the differential that broke was totally stock, with stock fluid.

Thanks, JBLX

 

[Mattyd926]

Rebuild move on

 

[adidas303]

I think I've heard Mugen brand may have some differential sun and satellite gears as replacements that might be a lil stronger, sorry I don't have any part numbers. Otherwise stock replacement would be ok as well, just maybe use a lil thicker diff oil. I don't own a Talion but I think they are also 10k/100k/10k diff oil weight Front/Center/Rear order. Maybe try like 200k in the center and like 50k front and 20k rear... The thicker oil may be able to take a bit more of the stress of the acceleration also. ?

 

[JohnnyBLX185]

Thanks for the quick replies.

The replacement gears are plentiful on eBay. But does anyone know if the AR310436 part number includes the pin that holds the sun gear on, or is that a separate part? Mine was sheared into three pieces.

 

[adidas303]

Thanks for the quick replies.

The replacement gears are plentiful on eBay. But does anyone know if the AR310436 part number includes the pin that holds the sun gear on, or is that a separate part? Mine was sheared into three pieces.

Those pins are going to be separate, AR310440 is part number for those!

 

[slick2500]

I think I've heard Mugen brand may have some differential sun and satellite gears as replacements that might be a lil stronger, sorry I don't have any part numbers. Otherwise stock replacement would be ok as well, just maybe use a lil thicker diff oil. I don't own a Talion but I think they are also 10k/100k/10k diff oil weight Front/Center/Rear order. Maybe try like 200k in the center and like 50k front and 20k rear... The thicker oil may be able to take a bit more of the stress of the acceleration also. ?

Yup these.
You need all of the Mugen gears, each set is enough to do 1 diff and you will want to do all 3 diffs at the same time.
https://www.amainhobbies.com/mugen-seiki-htd-differential-gear-4-10t-muge2238/p587568
https://www.amainhobbies.com/mugen-seiki-htd-differential-gear-2-20t-muge2239/p587569

Thanks for the quick replies.

The replacement gears are plentiful on eBay. But does anyone know if the AR310436 part number includes the pin that holds the sun gear on, or is that a separate part? Mine was sheared into three pieces.

Ar310440 is what you want. https://www.amazon.com/dp/B00NE0FQW0/ref=cm_sw_r_other_apa_i_5FqJEb3S2YBZE

 

[JohnnyBLX185]

Cool. Thanks for all the input. Maybe for now I'll just rebuild the diff stock and see if it holds--new pin and new sun gear, with a few spare parts left over.

BTW right now I'm running 500k center and 100k front, but haven't changed the rear oil yet--but I guess that will happen soon. My driving is mostly bashing or onroad hooligan-style so I was thinking something a little thicker for traction and drifting--so maybe 50K oil? I was thinking the 100k I have for the front might be too thick for the rear diff.

 

[3d-rc.myshopify.com]

A thicker fluid on road will have a higher chance to break those gears again. The center is perfect with 500 but if you are on pavement a lot I personally would use 60 front 30 rear. These diffs don't like shock too much. However if you don't mind the work go 100f 500c 250r she will be a drifting monster. But diffs will need maintenance more often.

 

[adidas303]

Specially running the bigger tires, I was wanting to ask which diff went out on ya, front or rear?

 

[JohnnyBLX185]

Rear diff. The sun gear on the left side shattered along with the pin. Couldn't tell which went first. I still had the stock oil in the diff when it happened.

 

[3d-rc.myshopify.com]

Rear diff. The sun gear on the left side shattered along with the pin. Couldn't tell which went first. I still had the stock oil in the diff when it happened.

I recommend getting a couple rebuild sets. It won't be the last time lol

 

[adidas303]

Hmm, the side with the lighter weight. Stock is 10k weight. My Outcast 6S I run a 50k/500k/30k and haven't had any issues since the change.

 

[Aive]

Shim your diffs too, you can buy the shims from amain: https://www.amainhobbies.com/mugen-seiki-differential-washer-set-muge0206/p3241

Watch this:

 

[JohnnyBLX185]

Do you suggest adding a shim behind both sun gears and doubling up on the spider gears? And then doubling up on the external shim on the differential for the ring/pinion mesh?

Funny, kind of reminds me of guy who did some mig welding on my Jeep. He didn't want to buy a limited slip for his buggy, so he shimmed the spider gears super tight--cheap LSD.

 

[jondilly1974]

Do you suggest adding a shim behind both sun gears and doubling up on the spider gears? And then doubling up on the external shim on the differential for the ring/pinion mesh?

Funny, kind of reminds me of guy who did some mig welding on my Jeep. He didn't want to buy a limited slip for his buggy, so he shimmed the spider gears super tight--cheap LSD.

The sun gear should get a Mugen shim as it is a larger diameter and supports the pin better. The V4 have shims on the planetary gears and shouldn’t need more.

 

[Aive]

For the V4’s, the planetaries each haves a shim, however, Rich’s advice is to add one shim to each pair of planetaries. So two out of four planetaries will have 2 shims instead of 1....

Here‘s another a couple of videos that basically demonstrates it:

I also add an external shim to push the diff cup towards the pinion gear.