One hard hit on a rock or a full-throttle desert pull and the factory knuckle ball can fold like paper leaving you stranded with a destroyed birfield and a massive repair bill. These HotMetalFab 3/16" heavy-duty gussets weld on in an afternoon and turn that weak spot into a tank. Thousands of 80-series owners have already made this the #1 preventive upgrade don’t be the guy who learns the hard way.
Why You Need These Gussets
- Made from 3/16" laser-cut high-strength steel – thicker and tougher than most
- Complete pair – includes both upper and lower gussets for driver + passenger sides
- Precision fit for 1990-1997 Land Cruiser (FJ80, FZJ80, HDJ80, HZJ80, LX450)
- Wraps the knuckle ball exactly where stress concentrates
- Ships raw and un-welded – weld them exactly how your rig needs
- Does NOT change steering geometry or suspension travel
Feel the relief of knowing the front axle on your $20k–$80k rig won’t grenade the next time you send it.
Installation Is Simple
- Clean the knuckle ball area (wire wheel or flap disc)
- Test-fit each gusset – they drop right into place
- Tack weld, check alignment, then fully weld with 7018 or good MIG wire
- Paint or bed-line to match your rig
Most people finish both sides in under two hours with basic welding skills.
Who Needs These Gussets?
If you own a 1990-1997 Land Cruiser and you wheel it harder than pavement princess duty, these are mandatory:
- Overlanders running 35s–37s and heavy armor
- Rock crawlers who actually use their birfields
- Desert/pre-runner guys pinning it in the whoops
- Anyone who’s ever seen a snapped knuckle ball on the trail and thought “not my rig”
Frequently Asked Questions (FAQ)
Will these fit my Lexus LX450?
Yes — the LX450 is a re-badged FJ80. They fit perfectly.
Do they work on solid-axle swapped trucks?
Only if you’re running 1990-1997 80-series knuckles and housing.
Can I weld them myself?
Absolutely — they’re designed for home welders. Just good penetration and you’re golden.
Do they clear long-travel or aftermarket steering?
Yes — they stay tight to the knuckle ball and don’t interfere with tie rods or high-steer arms.
Are they shipped raw or coated?
Shipped raw steel — ready for primer/paint, bedliner, or powder coat after welding.
What’s the lead time?
In stock and usually ships same or next business day via UPS Ground.
Is this really the weakest point on an 80-series front axle?
Ask anyone who’s broken one — the knuckle ball folds long before the housing or birfields give up.

