Big Bertha bolt kit?

[Oakley]

I've been hearing some horror stories of the diff bushing spacers failing and bolts sheering off.

anybody got experience with that?

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[WD Pro]

A little …

WD

 

[J17GT]

If you do any type of racing or hard driving on a sticky tire, the upgrade is worth it. I do some drag racing and had my entire rear cradle out last winter for upgrades. Sure enough, the driver side diff bushing was already starting to tear with ~30 drag passes. I upgraded to the big bertha kit with diff inserts.

 

[Oakley]

did you have to pull the pumpkin to install the bolts? that's the kit im thinking about. a little NVH to prevent catastrophe might just be necessary.

 

[J17GT]

did you have to pull the pumpkin to install the bolts? that's the kit im thinking about. a little NVH to prevent catastrophe might just be necessary.

Yes, best to pull the pumpkin. You need to drill out the mounting holes on the diff for the larger big bertha bolts. I also had to drill out the upgraded poly diff bushing sleeves and washers for the bigger bolts. Kelltrac now sells a kit with the correct size sleeves and washers with the bolts.

This is what to get: https://www.kelltrac.com/S550-Big-Bertha-Diff-Upgrade-Kit-Poly-Lockout-Kit_p_181.html

Small increase in NVH, just a little more gear noise. Totally tolerable to me and worth it for the significant upgrade.

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