Pair of new motor bearings for the turntable platter motor in the following Bang & Olufsen models, all using Motor part# 8400093 and 8400098, DC3V types MHN-3P2RDB and MHN-3P2RDS:
Beogram 1500 (Type 57xx only)
Beogram 3400 (type 5726 only)
Beogram 3404 (Type 5727)
Beogram 6000 (Type 5751,5753,5754 only)
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 (and it’s usually first when things no longer runs fine that owners first begin to think about it), 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 have been “smeared out” and the pores containing the oil will be closed. This typically results in audible wow and flutter (speed fluctuations).
In severe cases of dried lubricants, the motor can be difficult to rotate by hand or have seized altogether.
Bearings damaged by running with dry – or no – lubricants 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.
The safe solution is always to fit new bearings.
This is a set containing both bearings needed (top and bottom bearings are identical).
Custom manufactured by Beoparts-shop, 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 fingerprints and remains of old lubricants before fitting in the new bearings.
It is perfectly normal, that new bearings may need a run-in period in order to build up an even oil film, settle their position and adapt to the spindle.
Beoparts-shop recommends, that new bearings are run-in under normal load conditions, – that is with the belt fitted and platter rotating for at least 4-6 hours – with the tonearm raised (or cartridge dismounted, depending on model) to save needle playing hours.