Description
Pair of new motor bearings for the platter motor in the following Bang & Olufsen models:
Beogram 4002 (Types 5511, 5513, 5514, 5521, 5523, 5524 only)
Beogram 4004 (Types 5525, 5526, 5527 only)
Beogram 6000 (Types 5511, 5515 only)
(That is all DC-motor versions).
If the original bearings are renovated properly in time (before the motor starts running uneven or rough, starts whining or screeching, starts slowing down intermittently, starts running warm and becomes unable to keep correct speed) they should be able to perform fine for yet a lot of years.
If, however, the motor ran with dry oil or no oil at all, even for only a brief moment, it’s fairly safe to say, that the delicate bearing bronze material with the pores containing the essential oil will have been damaged. The soft material will be “smeared out” and the pores containing the oil will be closed. This typically results in audible wow and flutter (speed fluctuations).
Bearings damaged this way usually cannot be rescued.
Even a fresh oiling will in these cases only make the motor run fine for a short time. Perhaps a few days – perhaps merely an hour or two.
Any attempt to polish or sand the running surfaces of the bearings will only add to the damage in that it will smear out more material and clutter up pores with debris.
The only “guaranteed” solution is to replace the bearings.
If a green’ish residue is visible in and around the bearings and in remains of old and dry lubricants, it can be taken as a sign that the bearing surfaces are damaged beyond future use, because the green residue comes from the copper content in the special alloy used for these bearings.
The safe solution is always to fit new bearings.
This is a set containing two bearings; The small bottom bearing and the slightly larger top bearing.
Custom manufactured by Danish Sound Parts, these bearings are direct replacements for the original parts.
The bearings are pre-oiled (impregnated) and ready to fit. They will arrive oily and should not be wiped or dried before fitting.
It is recommended to clean the motor spindle using a soft lint-free cloth with isopropanol alcohol to remove finger-prints and/or any remains of old lubricants before fitting in the new bearings.
Note:
It is perfectly normal, that new bearings need a run-in period in order to build up an even oil film, settle their position and adapt to the spindle.
Danish Sound Parts recommends, that new bearings are run-in under normal load conditions, – that is with the belt fitted and platter rotating (but with the tonearm raised to save needle playing hours) – for at least 48 hours.
With a record on the platter press PLAY/START and then touch the < key briefly to stop the carriage motion, then press 45 to speed up the process.
The deck will now run the motor (and rotate the platter with the tonearm hovering) until you press STOP.
A non-stop 48 hours run-in will be best. If done over more sessions each session should be a least 8-10 hours non-stop to allow for proper warm-through etc.
MP-005
