Gear oil for horizontal bandsaw

I thought I'd take the gearbox cover off my Chinese 4" bandsaw to see if the gears needed more grease and a load of oil spilled out. So I need some fresh oil. The oil had the appearance and smell of EP90 gear oil and I was about to go to the local car spares shop to buy some when I came across various dire warnings on US forums about automotive gear oil having additives that will attack the brass/bronze gear wheel.

Is this true about EP90 being unsuitable for yellow metal gears and, if so, what oil should I use (that I can buy about half a pint of)?

Hello Otley,

​You were lucky to have gear oil in yours, mine of 115 mm size but similar origins had what might be described as light oil which was black with debris from both the bronze gear and steel worm. The severe wear was eventually traced to misaligned shafts; I cleaned it all up after putting that trouble right and refitted new bearings, which were completely shot and then refilled with EP 90.

I never considered the warnings that have been made of bronze attack by this grade of oil, but to use anything other in a worm drive is not satisfactory in my view so I think it might be best to check it from time to time. Have the blade carrier horizontal when you remove the gearbox lid, it will retain the oil in that position.

Do NOT use grease, the bearings need lubrication too.

Regards Brian

Unless you get water & combustion products in there, a problem is unlikely. EP additives are avoided in engine oils for this reason.

I researched the same question a couple of years ago and got confused answers. It seems that modern GL-5 oils should not attack copper but it depends somewhat on the application. A plain gearbox should be OK, but not one that includes synchronisers.

Based on some positive reassurance I found somewhere on the web I used Castrol EPX 80/90. After a year I opened the gearbox up and found a little bronze dust floating on the oil but no obvious damage to the worm. It's just more polished than it was when new.

I would worry about yellow metal much more if I was putting oil in an expensive classic car.

Cheers,

Dave

Thanks for the replies. I think I'll risk the EP90. While looking around for some information on lubricants, I found this US manual for the machine. It says grease the gears, but also has useful info on setting speeds and selecting blades :**LINK**.

Heavy diff oil will do , most diffs have shims that are copper alloy probably bronze and manual gearboxes have syncro rings made of similar stuff .

The stuff in mine is very thick almost like honey .

There is not much load there .

Ian.

As a 35+ year Land Rover runner EP90 oils are my thing. It is GL4 that is safe to use not GL5

One also needs to remember that EP 90 is not a 90 grade oil, it is an oil that behaves like a 90 grade oil under conditions of extreme pressure, ( hence the EP90 grade) the actual oil is much thinner more like a 40 grade oil.

If you want a heavy oil which definitely won't attack brasses , then you will need good old fashioned SAE90, or 140 even. Note that SAE 140 is so thick , that it is like golden syrup when cold, it is very viscous. This is one reason EP oils were developed, as they are much thinner than the equivalent SAE oil and therefore created much less drag in automotive gearboxes.

Worm drive boxes under extreme pressure need a Moly 90 weight oil which is 90 weight.

It looks like grey sludge from new.

Having said that these bandsaws are under no extreme loading and any oil is better than no oil.

The instructions for the Sealey bandsaw (model SM5.V3) recommends "annually replace gearbox oil -SAE90)

(This is the usual 6" x 4" bandsaw)

Edited By Robbo on 08/08/2016 22:54:11

i.e. a non-EP oil, which seem reasonable as the worm and wheel gearbox isn't hypoid.

Millers Oils supply such stuff for classic vehicles; I believe Castrol do as well, and I'm sure there will be others.

This is an excerpt from the Superwinch Husky manual, a winch often fitted to Landrovers etc. which contains a large bronze wormwheel.

Arctic -13°c to 15°c SAE 90 Oil

Temperate -16°c to 29°c SAE 85 / 140 Oil

Tropical 19°c to 43°c SAE 140 Oil

Note: EP (Extreme Pressure) additives can damage copper based alloys like phosphor bronze used for the worm gear and we do not recommend their use in the worm gearbox. If any doubt exists, consult your lubricant supplier’s technical department.

Edited By peak4 on 09/08/2016 12:11:00

Edited By peak4 on 09/08/2016 12:11:13

Edited By peak4 on 09/08/2016 12:12:14

SAE 140 isn't quite treacle thick. I was surprised to find it actually poured quite well the first time I changed the oil on a Norton Commander gearbox. Presumably SAE 140 was specified because the Truimph derived five speed cluster needed all the help it could get to coupe with rotary engine torque probably over twice what it was designed to carry.

These days I run Castrol R 40 in it which is an excellent oil for highly loaded sealed gearbox applications. Allegedly R can cope with loadings rather greater than most EP oils provided it doesn't get too hot. I'd be tempted to try it in my old Alpine branded bandsaw worm drive if the 'orrible thing were still in regular use. Nowadays a Manchester Rapidor power hacksaw and 14" varispeed Startright bandsaw have consigned it to the emergency corner.

EP90 oils are chemically active in that they change composition under heat and pressure to carry the load so you have to be sure that gear materials don't get involved in the reaction.

Clive.