Power Window regulator lacks 'power'

[Maurits Jonkergouw]

Hi list,

One of my power window regulator lacks 'power' ie. it's far more easy
to 'stop' it going up compared to the other one. Lucky for me it's
the passenger side, but still. I've read to keep the tracks
lubricated and maybe that's the only culprit (beside bad pulley
and/or frayed cable), but before checking it out, could there be
something wrong with the regulator itself I could fix while being
there. Any BTDT's?
--
Regards,
Maurits

'86 quattro GV (WR)
'85 coupé KV
'82 coupé DD