help! smoke from rear axle 6711

[grumpy6711]

went up the road today to collect topper and within 100m and 3 minutes from starting i noticed smoke coming from where the right hand brake pipe enters the bell housing!
it is not the brakes binding as it free wheels and i can even push it .
there was a 'clacking' noise as if the diff lock was on, so did some back and for to release it. now just an odd clack now and then i think (its a rattly old tractor.)
any ideas as what may be causing the smoke?
i would have thought the only things that could cause smoke would be clutch and brakes, but both seem ok.

 

[grumpy6711]

just removed brake cover plate to see if i could see anything obvious. nothing.
seems to only do it at 'high speed' as in road travel in 3rd or 4th gear. never been into 5th!
i suspect leaking brake cylinder onto something but there is no heat obvious anywhere. any suggestions anyone?

 

[Renze]

hanging brake. Also check the park brake release spring on the outside before taking it all apart.

 

[grumpy6711]

hanging brake? as in part of the brake mechanism (shoes?) hanging loose?
remember - wheels not binding at all.

 

[Renze]

hanging=binding. It doesnt need much to generate heat.