Sct410.3 diff leaking

[teknojim23]

I have a leaking center diff and wondered if it's just the o-ring that seals it or is it the grease on the outdrive too? I used synthetic permatex grease and it seem a little thin so wonder if that why. It's the side without the spur.

 

[Billl DeLong]

Yes, you need to apply grease on the recessed groove of the shaft as well per the instructions on page 4, steps B-1 and B-4 :

https://www.teknorc.com/wp-content/uploads/2023/10/SCT4102.0_instructions.pdf

Any general purpose grease should work fine, I prefer White Lithium Grease myself:

• Maintenance Tips

 

[teknojim23]

Thanks i did apply the grease but it was a synthetic and was not extra thick. Should.i use a thicker grease maybe? Also the o-ring would be seated but when I push the outdrive in the o-ring pops out a bit and it's hard to tuck back completely.

 

[Billl DeLong]

I prefer to use a dental syringe and use the out drive as a skewer to push the o-ring deep into the diff and use needle nose plier to press the o-ring in place to ensure a proper leak-proof seal:
https://www.rcgroups.com/forums/showpost.php?p=51858081&postcount=4

I use my finger to wipe away excess grease on the shaft before inserting the outdrive into the diff case:

 

[RustyUs]

Maybe check for a tear in the o-rings while doing a rebuild. I never had an issue with the older orange TKR5144 o-rings in my rides. I just use Maxima waterproof during rebuilds. It's worth noting that most new kits are using the TKR5144B o-rings. I'm not sure on the durometer of them, but I would think they are a bit softer and are used as a tunable part for diffs.

Softer o-rings equals more resistance?