These are my findings on various Garrard 301's and 401's that I have dismantled for relubrication.This guide is in response to inaccuracies that were on the Slatedeck websitewhich they have kindly amended regarding so called "steel" bushes. I am NOT a competitor to Slatedeck and my only aim is to give as much information as possible to Garrard users.
I would like to point out first that I am a qualified engineer. I was Technical Manager for a manufacturing company with its own engineering department and I was there for 28 years. I latterly designed sophisticated machinery and I had to have an understanding of all aspects of engineering and manufacture. I dealt with bushes and bearings on a daily basis. I had access to all documentation and technical matters for oil, bushes, bearings etc. Because the company I worked for had been in existance for over 100 years we often reconditioned machinery from the 1950s, 1960s and 1970s which is the same period Garrard were producing the 301s and 401s. Consequently I had access to manufacturing drawings and bearing suppliers catalogues from the same period.
In 2002 I gave up my career to concentrate on my hobby of selling records and hi-fi on eBay.
I have three Garrard 301s and one Garrard 401 as well as a few other turntables. I have had a number of Linn Sondeks. One of the best turntables Ive ever had was a Thorens TD 124 II.
Below is a photo of one of my Garrard 301 Bearing Assemblies which I sold recently on eBay.
A prospective buyer from New Zealand asked me if it had "steel" bushes. Unfortunately, he had read the Slatedeck website, before they had amended it, which mentions someone other than Garrard fitting "steel" bushes to many Garrard 301s.The rogue "steel" bushes they show in their photos are not steel but a grey sintered bush with a highcast iron content which were probably fitted by Garrard and probably came from a long established company called Oilite who still stock cast iron bushes which has always had reasonable bearing properties (although not as good as bronze). A standard Oilite bush is a sintered bronze material which absorbs oil and was fitted to some 301's and 401's. A lack of oil will have a more adverse effect on the spindle with the sintered cast iron type than the sintered bronze type.
Grease bearing 301s use bronze bushes which, technically, should have an elliptical oil groove machined into them and the upper and lower bush should have the oilgroove breaking out of the bush facing each other so that the greasecup between them can enter grease inside each bush when the cup end is screwed in. These bushes probably came from another long established company called Glacier or manufactured by Garrard themselves from stock phosphor bronze bar or bronze tube called "Encon". Phosphor bronze bushes, unlike Oilite bushes, do not absorb oil and therefore there is no way of lubricating them without an oilgroove machinedin them. The upper bronze bushes without oilgrooves on oiled 301's can only rely on oil seeping down from the felt washer. Upper phosphor bronze bushes on greased 301's rely on grease being forced up into them. With only 0.0005" to 0.001" clearance this is not enough to keep them well lubricated resulting in rapid wear and consequently rumble. However, I believe Garrard did not use oilgrooves and used plain phosphor bronze bushes instead with a reasonably sloppy fit to allow the grease to be forced between the surface of the bush and the spindle using the high viscosity of the grease to take up the play. Beware of anyone offering non-absorbant bronze bushes without oilgrooves or a very close tolerance fit as it is difficult to keep them lubricated unless you use a thin oil such as Redline 5W 30 which is a superb oil for all turntable bearings (see below for further information). Absorbant Oilite bushes are better in this application as a closer tolerance can be achieved without worrying about a lack of lubrication reaching the bearing surfaces. A good sliding fit is 0.0005" to 0.0007" or in metric13 to 18 microns (H7 is 0 to 18 microns). Too tight a tolerance may also create slight drag with wow and flutter. Not a close enough tolerance may cause rumble.
Oilite bushes are far cheaper than Glacier phosphor bronze bushes with oilgrooves and it would have been for these economic reasons, and others,why Garrard would have changed. (According to Loricraft..."In 1955 it became clear that the 301 would be too noisy for professional stereo monitoring. Various modifications were made up to 1964 . Most significant is the change from grease bearing to the oil bearing circa 1956").
A well lubricated grease OR oil bearing will last for decades. A non lubricated bearing, particularly the cast iron type,will eventually destroy the spindle which is an expensive item to replace.
The spindle is turned from Mild Steel 0.010" to 0.015" oversize then casehardened then centreless ground to a tolerance of 0.0005". My spindles have been 0.484" which is 31/64". This is an unusual size to choose as " would have been more sensible as " hand reamers and " bore bushes are stock sizes. However, manufacturers tend to like off standard sizes as it means customers have to come to them for expensive spare parts instead of going direct to bearing suppliers and this generates more income for the OEM (Original Equipment Manufacturer).
You must check the spindle for wear as a lack of lubrication will damage it especially if you have the grey coloured, cast iron, sintered bushes in your housing. A couple of dark coloured rings as shown on the photo are ok but if you can feel a slight indentation with your finger nail then the spindle has to be replaced or reground a few thou and matched with undersize bushes. Using a good spindle as a GO plug gauge you can check the bushes for play. The lower bush is normally ok as it is gravity fed with oil from the screw at the top. However, the top bush is only lubricated from the top felt washer which must be saturated at all times. If the bushes need replacing you can either pay a fortune for someone to do it for you (Slatedeck charge 98), or, I would obtain a couple of Oilite bronze bushes (only about 1.50 each) the correct length and OD and open them up to the correct ID with a boring tool on a small lathe (can't use a machine reamer as this harms the bearing properties. A hand reamer might be ok but the tooling cost for a special 31/64" diameter would be prohibitive. Also, reaming is not recommended as it can produce a glaze on the surface which harms the oil absorbancy). If concentricity is a problem then a bush of a larger outside diameter could be bored (not reamed) to the correct size then placed on a mandrel and turned to the correct outside diameter, this normally ensures concentricity. Most local engineering companies could do this for you, just look them up in your local Yellow Pages under Precision Engineers. I donot offer this service and I amNOT a competitor to Slatedeck, my only aim is to give Garrard users as much information and choice as possible.
The lower thrust bearing is normally again in good order due to gravity fed lubrication. However, it is worth checking that it doesn't have a flat worn on it. Having said that, if you can't hear any problems from the Hi-Fi News Analogue Test LP, side 2, track 6 then there is no need to worry. If there is "residual noise" then changing toa ceramic, brass, bronzeor hard chromeball typeshould solve the problem. Using sound editing software the dB can be measured for different materials, tolerances and lubricants.
As for the correct oil or grease? Any suitable lubrication would have saved the bushes and spindle from wear. Oilite suggest immersing their bronze bushes in SAE30 oil at 70 degrees C for 15 minutes before fitting. However, some oils of differing viscosity may impart a signature sound to the records depending on the wear in the bushes. This is only detectable if you have a perfect sense of hearing with a musical ear or sound editing software. Having been to too many rock concerts over the years Im not sure I can tell the difference any more aurally, but I do have Cool Edit Pro to check the dB for rumble etc. One oil which is highly recommended by Hi-Fi World magazine is Redline 5W 30 which I sell in handy 10ml screw top syringes. Of all the hi-fi magazines I find Hi-Fi World are not afraid to admit that analogue vinyl records played through a decent set up blows CDs out of the water. It is refreshing that their opinions are not bound by advertising revenue from the big CD and hi-fi manufacturers, unlike some publicationssuch asGramophone. A general purpose bearing grease should be adequate for grease bearing 301s. However, different types of grease may again impart a slight signature sound depending on wear, viscosity etc.
I hope this guide has helped to dismiss any confusion regarding Garrard 301 and 401 bearings, bushes and oil. Just remember to lubricate your bearings regularly. If you found this guide helpful then please click the YES button below.
For a close up photo of the above bearing assembly hit the link below.
Superb Turntable Oil
Afewpeople with commercial interests obviously found this guide unhelpful to their business. IfYOU found it helpful just hit the YES button below. If you want to hit the NO button then perhaps you would like to discuss any perceived inaccuracies with me first. I would be happy to discuss any aspects of the above via the eBay Message service.
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