Super 7 countershaft

[Maurice Cox 1Participant @mauricecox1]

After delaying for far too long, I have finally dismantled my Myford Super 7 counter shaft, early pattern, with a view to renewing the needle roller bearings. It is very noisy, worse when the belts are tightened properly, and practically unusable on the higher speed range. To my surprise, it does not have the needle roller bearings as shown in the manual, but plain bronze bushes. The O/D of the shaft is 3/4" and the bores in the casting 1". Assuming that I can get the bushes out, should the needle bearings be a direct replacement? I have found some in stock on the internet. How should I go about pressing them in please?Any advise welcome.

Maurice

[Maurice Cox 1Participant @mauricecox1]

[Jon GibbsParticipant @jongibbs59756]

Hi Maurice,

Steve Jordan on Youtube has some useful videos on the ML7 countershafy bushes that might help…

**LINK**

HTH

Jon

[DMRParticipant @dmr]

I seem to recall plain bush replacements as an option to the needle rollers at one time, and someone here may be able to help you if you should go down a bush replacement path. But really anything could have been done to the housing and/or the shaft (less likely as it's tough) to effect a fit. I cannot recommend going down the replacement needle roller path as you will find that it most likely still rattles and spews oil out. There are various questions on here about the problem, if you do the simple search for "Mk1" or "S7". The best answer is to go for a replacement clutch assembly as I did, and others have done. I can talk you through that as to what you need/ don't need. PM me if I can be any help. Another point is that if the shaft has ever been bashed out the wrong way – towards the headstock – at any time then it is messed up anyway. Page 32 in my early manual.

Sorry that it's somewhat negative for what you planned. Keep trying.

Dennis

[Maurice Cox 1Participant @mauricecox1]

Thanks for that gents. The assembly shows no sign of having been bashed. It came to pieces fairly easily, but I could not remove the pulley, so I had to drive the shaft out,with a hide hammer, towards the left. If this is the direction that DMR means by "towards the headstock", what damage am I supposed to see?

Maurice

[DMRParticipant @dmr]

Myford would have a reason to say that. Safe to assume that the shaft to the right of the roller bearing in the pulley is slightly larger diameter than the hole in the roller bearing in the pulley and the "hole" in the centre of the needle rollers or bushes in your case. A locating face to tell you when you have pushed it in sufficiently from the tailstock side. So since you have knocked it out the wrong way, you have either:

A) A damaged shaft or a damaged roller bearing or both. Or it has been done before anyway.

B) Since you say the bushes were worn anyway, then you haven't done any more damage to them than is done already. I still have my complete early clutch and covers under the bench, but it would mean me having to strip it down to take accurate measurements for you.

It was the needle rollers that made all the noise. Since you didn't have any, it suggests that the outer bushes on the shaft and the bearing in the clutch were all bouncing around somehow. Did it rattle with the clutch engaged?

Sorry for the negative again, but keep trying.

Dennis.

[Maurice Cox 1Participant @mauricecox1]

This very strange. The shaft is unmarked except for some polishing where the bushes were, and is completely parallel for its whole length. I assume we are talking about the same thing; it's the type of clutch which is an expanding ring inside the cone pulley. Apart from adjusting it little twice in fifty years, it has given no trouble. Since the shaft is not worn, I now do not know whether to replace bushes with bushes, or change to needle rollers. I have found both the size I need on line.

Maurice

[Brian OldfordParticipant @brianoldford70365]

Maurice. You say you drove the layshaft out towards the left. That is incorrect. You should have removed the two-step pulley first and removed the shaft towards the right. I.e. the tail-stock. Driving it to the left may have damaged things further marring the shaft itself. On my previously owned Mk1 I did change the four needle rollers and the ball-race (5 bearings in total). It quietened things down quite a lot but it continued to make a mess with the surplus oil.

If there is some marring to the shaft oilite bushes may be a better replacement for the needle-rollers.

I did find quite a bit of the noise on my Mk1 to be the clutch release mechanism. The actuating shaft was worn in the hole it runs in causing the outer end (in the release lever) to "orbit" and thus cause vibration. Fortunately the actuating shaft had taken the lion's share of the wear and the hole in the shaft was OK. I made a replacement actuating shaft from a piece of 3/8" silver steel and also replaced the ball-race in the lever with an RS version.

When I sold it on it wasn't perfect but it was quite usable even at the higher speeds.

[Maurice Cox 1Participant @mauricecox1]

As I said I had to drive it to the left as I could not shift the drive pulley. I still can't see what I am supposed to have damaged. The shaft is smooth and parallel, with machine indents for the grub screws. There are no burs on it and it slides nicely through the bushes. The only part it has to be driven through is the ball race in the cone pulley, and even that isn't that tight. The worst wear that I can see on the shaft is at the pulley end; it's about four tenths undersize. It seems to be the bushes that are worn. I shall order four more tonight. Thanks for your advice gents

Maurice

[DMRParticipant @dmr]

No further responses again Maurice, so……

You seem to have come to the right option to replace the bushes with bushes. Unless you opt for a modern clutch replacement which I can promise will solve your problems. If you can see that the existing bushes have marked the shaft, then new roller bearing are not likely to be a sufficient fit to work at all. You should also consider replacing the bearing in the pulley as it may well have been stressed while the shaft went out the wrong way. As to your original query about getting the old ones out and the new ones in, you seem experienced enough to know that you need to keep things square on to the recesses and use a press if possible, not a hammer!

Plenty of sites for "bronze bushes", take your pick and good luck, but remember to drill and oil hole if necessary and debur before you push them in.

I can send you the relevant pages from the early manual about the clutch/belt replacement if you haven't got them.

Ah, you just beat me to it Maurice with your 17:38 response, but the ball race should not be a loose fit on the pulley if that is what you mean?

Dennis

Edited By DMR on 14/07/2017 17:55:08

[DMRParticipant @dmr]

Maurice,

I have unearthed my early clutch set. It occurs to me that if you have still not shifted that pulley of the shaft end then you cannot reinsert the shaft properly anyway. The pulley on mine is held by two grub screws; do you mean you cannot get them out, or that, having unscrewed them the pulley won't shift (in which case use a hammer but don't break the casting)? If its the former, then you have a problem as they are probably in recessed holes. Which is it? Having removed the grub screws that shaft will knock off.

Dennis

[Maurice Cox 1Participant @mauricecox1]

Thanks Dennis, I intended to change the ball race anyway. The pulley gradually moved along the shaft as I tapped the other end; once I got the shaft out I managed to get it off. The ball race is not loose in the pulley at all. I just meant that, while a very tight fit on the shaft, it can be move along it without using silly amounts of force. Is it the ball race that I am damaging by driving the shaft the wrong way? It looks like an ordinary radial thus type, so I can't see what difference it makes. I have the manual thanks.

Maurice

[Brian OldfordParticipant @brianoldford70365]

Just a final note for completeness.

When I removed the two-step pulley from the layshaft. After slackening the two grub screws I did try driving the lay-shaft out towards the tail-stock end of the machine. I found it so tight I began to get a bit twitchy about breaking the casting. I eventually realised that discretion is the better part of valour and decided to use a puller to get the pulley off.

Once the pulley was off I was able to drive the shaft towards the tail-stock with gentle blows from a hide hammer. Having used them on other projects I'm sure you find sintered bushes quite satisfactory. Like a steam loco lubricate before and during use.

[Maurice Cox 1Participant @mauricecox1]

I have four "Oilite" bushes on the way for my countershaft. Do I have to prepare them in any way before insertion? Someone told me to soak them in the lubricating oil prior to fitting. Also, I intend to change the ball race. It has retained its grease very well over the years, but I would like to fit a sealed one. Is there a problem with this? Thanks again.

Maurice

[HopperParticipant @hopper]

Oilite and similar sintered bronze bushes generally come pre-soaked with oil, ready to install. No need to drill an oil hole through them like you would with a solid bronze bush. Just drip oil down the hole in the housing after installation and it will spread itself through the "honeycomb". No reason you can't fit a sealed ball bearing in place of the old one.

[Maurice Cox 1Participant @mauricecox1]

Thanks Hopper, should be up and running again soon now. Cheers

Maurice

[Maurice Cox 1Participant @mauricecox1]

Sorry to be a nuisance about this, but I want to get it right. I cannot drip oil into the housing as Hopper suggests, as the oiling points all have oil nipples fitted. Will oil from an oil gun permeate the "Oilite" bushes fast enough to get enough oil through in a reasonable time? There are two bushes fitted at the pulley end of the shaft with a small space between, so this fine, but I have just removed the bush from the cone pulley. It is "Oilite" bush, and has had an inexpertly drilled hole put in it under the nipple. Also I am so far unable to find a sealed ball race of the correct diameters, and only 5/16" wide, so it will be getting another open one. This is fine, but what should I lubricate it with. The stuff in the old one has stayed in for about fifty years!

[DMRParticipant @dmr]

Maurice,

When I said about 'oil holes if necessary' I did not know what you would be buying. As Hooper said, there is no need for any hole drilling in Oilite bushes; they will run for a fair bit of use without any replenishment, provided they are a good fit to start with (and that includes on the shaft). The amount of oil you will use is wholly dependant on your use of the machine and only you can judge that.

As to the original oil nipples, the best plan is probably to just remove them but……………that leaves an upward hole for dirt and swarf to enter, so remove the nipples, fill the resultant hole from an oil can and replace the nipple. Another possibility is to stick a bit of wool, etc in the hole and just keep that moist. I guess they were threaded 2BA so you could substitute nipples for short screws if you want.

As to oil, SAE 30 (a descent motor mower oil, etc) or thinner should be fine. Nothing sticky like chainsaw oil, and never a grease no matter how rattly you find things.

Get going again and see how you get on. It is not a matter of getting oil through the bushes "fast enough" as you imply. Suggest you read up on the Oilite bush to understand better how it is meant to function. if you still find play or any looseness in the two bushes that sit close together, do not try to keep oil flowing through and out of them. It would be futile and a waste of oil. Just put some in (via the nipple hole) from time to time and the bushes will do the job. It is very much a suck it and see, totally dependant on the use the machine gets. There is no need to have oil dribbling out anywhere all the time.

Trust that helps.

[Brian OldfordParticipant @brianoldford70365]

Maurice

If you do chose to remove the oil nipples to make lubricating the bushes easier you might want to consider fitting some of those sprung flap type oilers instead. There's some here to demonstrate the type of thing I mean. http://www.ebay.co.uk/itm/BRASS-PLATED-STEEL-FLIP-TOP-OILERS-M6-THREAD-/192210586821?hash=item2cc0a4ccc5:g:48wAAOSwsXFZOBk3

[Maurice Cox 1Participant @mauricecox1]

Thanks gents for your help. I was considering putting a couple of oilers with sprung flaps on the two shaft bearings. However, there is a third one mounted on the hub of the cone pulley, and obviously it rotates when the clutch is engaged. Not sure what to do here. I thought of making a short threaded reservoir with a threaded bung to keep the oil in. The new parts have all arrived this morning. The bushes, clearly labeled "Oilite" show no signs of being impregnated with oil, not to the touch, no smears on the inside of the bag, and no odour. So, do I soak them? This is what we did with quite small ones that we used when I was working. They were kept under oil in glass jars until needed, but I was never sure that it was something that one of my bosses thought was a good idea.

[Brian OldfordParticipant @brianoldford70365]

Maurice

I would speculate that it would do no harm to soak them as you describe. Should you end up with too much oil we both know the countershaft will self-moderate that situation with stains on your shirt if the cover is left up when running. . . . . . . .How do I know?

[Maurice Cox 1Participant @mauricecox1]

I have just finished pulling the old bushes from the casting. Quite a tight fit. The new ones just about wring onto the shaft as they are. I assume that they will get smaller when I press them into the casting. Time for the expanding reamer? Or do I have to lap them?

[BrianParticipant @brian]

Maurice, take alook at the work Steve Jordan has covered on You Tube it deals withe the work you are doing. click this link hoping it works https://www.youtube.com/watch?v=u9UuUctxy4k. oops sorry cut and paste.

Regards

Brian

[Maurice Cox 1Participant @mauricecox1]

Thanks, will do.

[Swarf MakerParticipant @swarfmaker85383]

Oilite bushes, due to their porous nature are designed to be at the correct (designated) bore size when fitted into a housing of the prescribed dimension. I would not expect them to be a tight fit on the shaft prior to fitting. If your bushes are anticipated to be under size in the bore when fitted, it will be because the housing dimension is incorrect or the fitting procedure is poor.

If you attempt to ream these bushes in situ, you will 'smear' the honeycomb structure of the oilite and thus close of many of the pores that hold the oil. Thus the self lubricating properties will be compromised.

If the original bushes were oilite then the housing for them should be of the correct dimension. These bushes are actually quite fragile and to obtain the correct clearances you need to be very precise when installing them to ensure that they are accurately located along the axis of the bore, otherwise they will become (perhaps very slightly) distorted as they are inserted.

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