Tom Aurand wrote
EddieM wrote:
Tom Aurand wrote




I'm betting the motor bearings, capstan bearing
and/or pinch roller bearing.
All are likely sleeve bearings, can be cleaned with
degreaser and re-lubed with sewing machine oil.
Carefully and thoroughly clean the capstan and
pinch roller after reassembly and before ANY
operation. If done well should last for 5 years
of moderate use.

I'm thinking it's also the motor and that it's getting weaker.
Well if it's old, it should be replace. I wonder how to replace
these things. The speed gets worse over time so eventually
it's going to get worse. This reel to reel recorder's problem
is time and it's getting old.

There's practically nothing in those old motors to "get weaker"
except plugged up bearings. Pretty unlikely to find a replacement.
A thorough cleaning will resolve. Belt replacement would be good.

Well I guess then that it doesn't take time to plug them bearings in
the motor to make them weaker.

csblue wrote:

I am trying to restore a Sony TC-630 reel-to-reel recorder. It records
fine,
but after I play the recording for a period of time, say ten minutes, the
speed starts to slow down and gets worse with time. After turning the unit
off and letting it rest awhile, the speed is correct again for a time,
then
slows down again. I have lubricated and cleaned everything that I should.
Any ideas???

Thanks,
Steven