Metal in Trans Fluid

[sapote]

I have zero experience rebuilding a trans but isn't the circled part from this screengrab a pair of syncros?

You're right!
My bad as I had never thought they put the synchro on the intermediate shaft for the 3rd and 4th, as it's a long way to reach the slider with the shift rod at the upper right corner. I label the 3 shift rods: R, 1/2 and 3/4.

So with both 3 and 4 synchro submerged, then why only the 4th sync with issue?
Btw, unless the box has only 1/4 qt of oil, filling the box a little lower doesn't make any difference for the wet 4th synchro.

I still don't think bad synchro is the root cause here.

[eacmen]

BTW a month ago this guy did a great video with a tear down and re-seal of the 420G:

https://www.youtube.com/watch?v=ueI6AaQFhPU

Although he labeled the large shift fork going down the side of the trans to the intermediate shaft 5/6? Maybe that was just a mistake.

[oceansize]

BTW a month ago this guy did a great video with a tear down and re-seal of the 420G:

Although he labeled the large shift fork going down the side of the trans to the intermediate shaft 5/6? Maybe that was just a mistake.

That video is fantastic.

[sapote]

Yes it's the best video so far for disassembling this box.
Couple errors in calling the 5/6th shift shaft as counter shaft at 17:21, and calling the 3/4th as 5/6th shift shaft at 40:39

[bigjae46]

BTW a month ago this guy did a great video with a tear down and re-seal of the 420G:

https://www.youtube.com/watch?v=ueI6AaQFhPU

Although he labeled the large shift fork going down the side of the trans to the intermediate shaft 5/6? Maybe that was just a mistake.

Nice! That looks far more orderly than my experiment disassembling a dead 420g. It went...pull the halves apart, a bunch of parts fall onto the floor and then I say "fuck me".

/experiment

lol