breaking bolts in hd gear sets

[Wh200y]

so little bit of info for you.
motor: tekin roc 412 3100kv
esc: holmes trail master
battery: 3s 45c
gearing:
pinion: 16tooth
spur: 68 tooth
diff gearing: 36/14

insicion spools for front and rear will be here Friday...

so my issue is that I am shearing the bolts that bolt my ring gear to the diff cup. this has happened twice now with the first time it accually shearing the bolts and tearing the diff cup apart. I do have the drag break turned up pretty high and I feel this could be the issue but I do beat on it pretty hard when I'm out crawling. ive got everything else pretty much bullet proof and haven't broken anything else for a very long time its all vanquish so... I do currently have the stock diff cups and lockers installed but fear that with a full metal spool it will increase the harshness on the bolts I keep shearing. anyone have any suggestions for me. id really like to keep my drag break where its at.

Thanks in advance

[WHITE-TRASH]

Sounds like your screws were loose. Under torqued hardware will fail before over torqued. Loctite the screws in the new spools and I bet your issue goes away.

[svt923]

I have never had this problem but there are a few things that may help.

Since the HD gear sets are helical cut, they exert some force outward on the gear. This force may be pulling the screws out of the plastic diff cup enough to cause some play between the diff cup and the gear leading to snapped screws. The Incision lockers should prevent the screws from backing out (as long as you remember to use thread lock, we have all forgotten it at some point ).

The other thing may be the screws themselves. Cheap grade 8.8 hardware only has about 2/3 the tensile strength of grade 12.9 hardware. Stainless steel would be even weaker than the grade 8.8 stuff. Get some quality grade 12.9 screws, you can buy them in quantities of 100 from fastener stores or in smaller quantities from Amain.

https://www.boltdepot.com/Product-De...?product=13323

ProTek RC 2x6mm "High Strength" Socket Head Cap Screws (10) [PTK-H-1003]

[Wh200y]

Thanks guys I'll give it a try and see what happens.

[Wh200y]

And svt923 if you where closer I'd give you a big wet kiss. You even took the leg work out of it for me by posting links to what I need. Your the best thanks a lot.