Mobilgear 632

Andrew, I've got some ISO VG220 gear oil if you want some.

Peter

I've got some very heavy EP gear oil, can't remember the grade but not your usual car stuff, (might be 220) managed to buy it in 5l quantities from Rock Oil

I'll have a look tomorrow, I think I've got 5l spare

Tim

Peter, that is very kind, do you know what the difference is between the VG220 and VG320 ? (and not 10 before JS or Tony pipe up !)

AWEM

An SAE140 back axle oil will probably as good or better than the original! It will be a of a similar viscosity.

Oddly enough, one of the Pedrazzoli Mec Brown saws has just turned up in the labs at work from another site. Unfortunately, I don't think that they want to get rid of it.

Mark Rand RTFM

Cheers Tim that would be good

AWEM

To put it into more familiar numbers:-

Mark Rand RTFM

If you do acquire it Mark check the gearhead backlash - mine had totally stripped the teeth off the bronze wormwheel. Probably years of abuse with the wrong oil in it! The wormwheel has a tapered clutch surface making it a bit more complicated to homebrew one. I was very impressed that there is no problem with spares for machines going back to the 1960's

AWEM

Oils are not my thing but the mention of SAE 140 suggests a solution. I once had to obtain some for a French Hotchkiss car. There wasn't any in the whole of France. I got him SAE 140 for a LD150 Lambretta back end. It may be a more appropriate spec. Certainly you will get 5 litres from local wholesalers. I got 5 litres of best Loire ' red' AOC in exchange.

Norm

Just the viscosity as far as I know, 320 being a bit thicker than 220.

The gear oil I've got comes from Ovoline, we used to keep a 50lt drum in stock for use on our injection moulding machines.

We actually used the gear oil in place of the slideway oil and also for the pumped toggle lubrication system, as it has a very good tackifier in it, so it stayed on the machines and didn't drip oil on the mouldings instead. I also used if for lubing the milling machine.

Anyway, I've got the best part of 4litres sitting in a container that you're welcome too, just not sure how to get it to you.

Peter

Andrew I'm interested more in what you found when stripping the head. When I stripped my Mec Brown, there were almost no signs of wear on the bronze gear, a tiny amount of play in the bearings, and the dished washers for the clutch looked "dished". A tiny amount of backlash in the keyway, so I remade the key. I did notice the gear wheel mount that is supposed to slide on the key was binding, so the clutch tension ineffective. I fitted new bearings, but never got around to reasembling the rest of the saw, so dont know if it cured that awful sound you get when cutting. I do realise, the angle of approach of the blade to the material affects how the saw cuts, and the blade TPI. If I cut 80 x 4mm flat mild its ok, cut 40 x 18mm and it complains loudly. AFAIK they all seem to do this, so am interested if yours continues to do so. Bob

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Bob,

Apart from a totally destroyed wormwheel, everything else was in very good order. Not having a manual I made the mistake of undoing the nut on the end of the wormwheel shaft to try dismantling that way, not realising it all came out as a 'cassette' - so managed to destroy the sliding pins that retain the inner nut, but apart from that it was suprisingly good. I now have the manual (ex Faserblazer on ebay) - always useful after the event. It advocates moving the centre line of the saw back 5mm from the centre line of the bar you are cutting.

AWEM

I seem to remember that some types of EP oil are very very wrong for bronze. (best read with lisp)

Thanks I got the book first from the same place first. Both my Mec's have the sticker on that describe moving the centre line and the TPI for different types/sizes of material. It's a pain when swapping from different sizes often to adjust the centre line. It seems its the blade that vibrates that causes the noises and not the gearbox, hence the adjustments required. I'm saving up (£4000) for a MEP column saw, a dream to use, slices through bar like the proverbial knife. Bob

What I have is SAE 85W/140 EP gear oil, but it looks as though you are sorted a bit more locally. If not, it looks as though I've got a trip to the midlands coming up in the next week or so, if that would help.

Cheers Tim

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machine.

Peter, and all other who offers suggestions, many thanks.

As a temporary expedient I've popped some EP90 in, which was the thickest that the local car place had. If I trip over some ISO 320 I'll change it in the future but for the very intermittant use it'll have with me I reckon it'll do. (Though I do remember some comment about some gear oils being incompatible with bronze as someone else mentioned - any hard facts anyone?

Incidentally, as all this was caused by the demise of the previous bronze worm wheel the casing was full of 'bronze paint' when I stripped it. I cleaned it up as best as I could before re-assembly, but decided to flush it with 15W40 before putting in the thicker stuff, to get out as much muck as I could. Even after four flushings I could still detect traces of bronze in the flushing oil.

AWEM

Active sulphur EP additives are the enemy:-

Mark Rand RTFM

So what do the gears look like? Spur? Helical? Unlikely to be hypoid, I would have thought. If they are *not* hypoid you may not need an EP oil, in fact you have to be a bit careful as EP additives can attack copper alloys (brasses and bronzes). As you have found out from the price, these oils are for high rating gearboxes.

ISO 320 is on the boundary between SAE 90 and SAE 140 gear oil, or just a bit thicker than SAE 50 Engine oil. So you might well be fine with a good

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hypoid, I

The gears are a steel worm and bronze wormwheel. I bought the Pedrazzoli Super Brown cold saw as 'burnt out motor' on ebay, but infact the dual speed motor was fine, and the wormwheel was totally stripped. As I understand it I should avoid a GL5 spec oil due to bronze corrosion issues and go for a GL4