Birfield forensics ? (1 Viewer)

[671fj40]

Any idea of what what caused this damage? 72 fj40 I bought three years ago. Just getting around to rebuilding the knuckles. Did the passenger side first. Other than being too loose all was in good shape. Replaced upper/lower bearings and axle seal. Torqued everything down with the original shims and it was still too loose. Replaced shims with the 2 supplied with the rebuild kit and came up with 5 lbs of resistance and called it done. Drivers side was different #1 The nuts on the knuckle arm were loose and the cone washers are missing. They were replaced with just flat washers. #2 The bottom knuckle bearing cap was also loose but have the cone washers in place. I could move the knuckle up and down enough to see, feel and hear. Once the axle was out, knuckle removed and things cleaned a bit I can see this damage (clearance issue?). My guess is that perhaps previously a birfield joint broke and was replaced? I don’t see damage on the current joint.

 

[White Stripe]

If the knuckle was very loose it could probably cause that wear. Also look at the condition of the locking hub

Any idea of what what caused this damage? 72 fj40 I bought three years ago. Just getting around to rebuilding the knuckles. Did the passenger side first. Other than being too loose all was in good shape. Replaced upper/lower bearings and axle seal. Torqued everything down with the original shims and it was still too loose. Replaced shims with the 2 supplied with the rebuild kit and came up with 5 lbs of resistance and called it done. Drivers side was different #1 The nuts on the knuckle arm were loose and the cone washers are missing. They were replaced with just flat washers. #2 The bottom knuckle bearing cap was also loose but have the cone washers in place. I could move the knuckle up and down enough to see, feel and hear. Once the axle was out, knuckle removed and things cleaned a bit I can see this damage (clearance issue?). My guess is that perhaps previously a birfield joint broke and was replaced? I don’t see damage on the current joint.

View attachment 2625380

View attachment 2625381

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and the spindle bushing.

 

[pb4ugo]

A broken birfiled would show scarring and random gauging all around the inside of the knuckle and ball. Your scarring appears to be limited to the top and bottom of the knuckle and ball. My guess is with the trunion bearings being bad and the knuckle moving up and down, the birfield large end was rubbing inside the top and bottom of the axle housing ball.

 

[671fj40]

Cleaning the knuckle I found a piece of metal. No clue as to what it was? I may have tossed more pieces out with the old grease. It is hardened steel and by itself could of caused the damage before it found itself a spot to rest. Looks maybe like a roller out of a bearing? Although the bearings I removed were bad they weren’t destroyed?

 

[1969FJ]

Perhaps a broken birfield at one time, repaired, but pieces left in there to do damage ?

 

[germaneighter]

I know this is an old post but I just found it. I found similar damage from a previous issue this last week when I started my front axle tear down.

 

[671fj40]

That looks ugly my friend

 

[greenbeasty]

That made some racket!

 

[Jack S]

both pictures look like they were ground out by prior owner to fit fj60 birfields in, they are bigger and need to be clearanced. It does not look to me like it is from rubbing.