ML7 Pulley & Pinion Gear Help Please

[Jon GibbsParticipant @jongibbs59756]

I had one of those 3am moments and would appreciate some advice please…

The day before yesterday my old ML7 spindle pulley was slipping on the bronze bush while drilling some big bore holes and so I spent a bit of time trawling old posts and found one which suggested just using Locktite.

So, after cleaning the muck and oil off the right hand side of the pulley cluster I dribbled some Locktite into the gap all the way round in the hope that it'd make its way into the joint and stiffen things up – and bingo it worked a treat.

…but then at 3am this morning I thought about the backgear oiling.

Did I need to do anything special to align any holes to make sure that the oil from inside the pulley can get behind the bronze bush to lubricate the spindle in back-gear before locktiting it all together?

Many thanks

Jon

[Jon GibbsParticipant @jongibbs59756]

[KWILParticipant @kwil]

No holes!

[Jon GibbsParticipant @jongibbs59756]

Sorry KWIL I'm probably being a bit dense – Do you mean there are no holes to worry about?

[KWILParticipant @kwil]

Correct, normally just press fitted when new.

[Jon GibbsParticipant @jongibbs59756]

Ok, thanks very much.

I was looking at this picture on the Myford website…

and seeing the hole thought there may be a corresponding one on the pulley cluster.

…but no sweat then

Jon

[Jon GibbsParticipant @jongibbs59756]

Well I've limped along for almost a year but it keeps slipping when I do anything heavy and I feel I'm going to have do something about it once and for all.

The question is what?

I think I'm probably going to have to dismantle the spindle and try to separate the pulley from the gear and get some loctite in there properly unless anyone has any better guidance please?

Is there an idiots guide to dismantling and then reassembling the lathe spindle? My ML7 is an original with white metal bearings. How do I set the thrust bearing for example? I have Ian Bradley's book and the official manual but that's all and neither of these give anything other than a 10000' view. I'm assuming that while I'm at it I should fit a new v-belt as well.

Many thanks in advance – any guidance gratefully received.
Jon

[Brian WoodParticipant @brianwood45127]

Hello Jon,

it is a good few years since I had my ML7 and I simply can't remember the details you are looking for. However, by posting, this will bump your query up for others to see and hopefully give you what you need. It was running the risk of disappearing off the bottom of the page

Regards Brian

[Gordon AParticipant @gordona]

Hi Jon,

Dismantling the ML7 headstock is not difficult if you proceed with great care.

There is a threaded collar at the left hand end of the lathe spindle with a grubscrew in it. If you loosen this screw you should unscrew the collar a turn to make spindle removal easier. You could mark the position of the collar on the spindle before unwinding it, or follow the rather vague instruction from the Myford operating manual on reassembly to tighten enough to eliminate end float without "undue friction by over tightening". I have used the latter technique with no problem.

You will probably need to remove the belt guard to get to the cap screws holding the left hand bearing cap (imperial allen key required). Lift the cap very carefully from its seating (some persuasion may be required) and note the position of the shims on each side, set aside carefully as these shims and their position are of paramount importance. The drip oilers can be left in place, but if you remove them plug the holes in the bearing caps to keep out dirt. From this point on cleanliness is vital.

Repeat with the right hand bearing, noting position and orientation of the shims. Carefully rotate the spindle and lift it out of the lower bearing halves taking care not to dislodge the whitemetal bearings.

Protect the spindle by wrapping it in something clean and remove the 2BA grubscrew from the 25T gear at the left hand end. This gear has to be removed and may take some persuasion, likewise the distance sleeve after the locking collar, thrust washer and thrust bearing have been removed. The vee cone pulley assembly should then slide off.

It is then your call as to whether you repair the gear/pulley assembly or fork out nearly 90 Quid for a new one from Myford! As regards the hole in the gear assembly, I would be inclined to line it up with the oil nipple in the pulley assembly.

Re-assembly is just a repeat of dismantling but making sure that everything is absolutely clean. To align the 25T gear with the half thread on the spindle I used a short piece of bar slightly smaller diameter than the core of a 2BA to guide the gear back into alignment with the spindle.

Before re-fitting the spindle, take out the countershaft and fit a new headstock belt.

Gordon.

[Jon GibbsParticipant @jongibbs59756]

Hi Gordon, Brian,

Thanks for your kind postings. As it happens I managed to dismantle the spindle last night and have made a start.

After separating the pulley and pinion gear it is clear that the holes are supposed to align particularly since mine is an early model and has the oil hole for the backgear in the bottom of the groove of the middle pulley. Without aligning the holes there's no real way for the oil to get to the spindle.

My new belt should arrive in the next couple of days and then I can reassemble everything but I've already managed to locktite the pulley on, clean the swarf and muck out of the headstock casting, cleaned and lubricated the countershaft and set the shims on the bearings. I was really pleased to see the state of the white metal bearings and the spindle – they're all as smooth as baby's bums!

Thanks again

Jon

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