49 gearbox a10 motor

[shuswapkev]

I have a bits and pieces a10...all works great.. the case is 49...engine is 51...not much of the internals are original with the cases...
except...

makes a bit of noise in third gear..howling...  obviously greater when under load...going up a hill...taken apart....cant see anything wrong... neither 3rd gear pinion has a bushing to wear...??  could be mismatched gears (from different gearboxes) as I made the gearbox out of a bucket of parts...???
the rest of the gearbox works fine.....shifts real easy...neutral is very  easy to find even when motor Is running...

any advice as to what I should be looking for??

thanks for any help...

[muskrat]

G'day Kev.
Ah, they ALL do that, Sir.
Some a bit more than others. My s/a is a little better than my plunger. Only seems to be in third.
I use a little Nulon gearbox and diff treatment in them. It helps a little with the whine and shifts are better.
Cheers

[shuswapkev]

muskrat
  thanks for that...sort of suspected might be the case as...not much there to really go out of synch...and mismatched gears do make a lot of noise... as in when you rebearing a differential...
my shovelhead started doing that about 10-12 years ago...and I have replaced both 3rd gears..shaft..retimed with factory tool...still howls...?? not real bad...but??
I drill all my drain plugs and install rare earth magnets..and not much more metal on it than what I would expect..