SAE 90 vs 140 for swing arm spindle

Like most trying to keep a 140 weight oil in the swing arm is "challenging", so in an attempt to improve the situation and working in a commercial vehicle workshop i had access to Mobile Chassis LBZ a semi fluid grease... before people jump saying you cant use grease, this isn't grease as you know as it is designed for automatic chassis lubrication system and has such needs to be semi liquid to be pumped around... to use a comparison its around the same viscosity as golden syrup.
It can be pumped in easily using a grease gun, but i have sealed up the nipple so i remove it & top up using a syringe.
To be honest in the height of summer (oh how i wish) there is a very small dampness, but this is nowhere like the "moistness" using 140 weight oil

I like the idea to use STP. In my mind, I will think that the leaking will be reduced due to its higher viscosity.
It doesn't matter what the reality will be!!
Dennis

olympus said:

Like most trying to keep a 140 weight oil in the swing arm is "challenging", so in an attempt to improve the situation and working in a commercial vehicle workshop i had access to Mobile Chassis LBZ a semi fluid grease... before people jump saying you cant use grease, this isn't grease as you know as it is designed for automatic chassis lubrication system and has such needs to be semi liquid to be pumped around... to use a comparison its around the same viscosity as golden syrup.
It can be pumped in easily using a grease gun, but i have sealed up the nipple so i remove it & top up using a syringe.
To be honest in the height of summer (oh how i wish) there is a very small dampness, but this is nowhere like the "moistness" using 140 weight oil

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Not saying you're wrong, just have questions.

If you plug the ends of a spindle on the bench and fill it with 140, the tiny hole in each end of the spindle will take a VERY long time to drain the spindle but it will eventually happen. How would that compare? Regular grease will almost immediately block the hole and harden so regular grease does nothing.

I unscrew the existing oil fitting and use a pump oiler in the hole. Be very careful not to pressurize madly because it absolutely will blow the far cover right off the skinny rod.

As long as you are not overly retentive aboit the dribbling, just give is an oil up once per riding season...the intent is to saturate the oilite porous bushings...not keeping a volume in the spindle bore.

olympus said:

Like most trying to keep a 140 weight oil in the swing arm is "challenging",

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And basically unnecessary as the oil is put there to recharge the sintered bronze bushes it's not an oil bath so once the bushes are recharged the excess oil can drain away. If owners were really bothered about keeping the oil in the assembly they'd use the later seals and not the 'dust covers' and O rings.



The oil will fill the RH cavity if the oil nipple is used as it doesn't pump directly into the spindle then drain out of the LH end of the spindle into the cavity at that end and soak into the bushes that way. If the central bolt hole is used to fill then the oil will run out of both ends of the spindle. I have a number of spare spindles, none of them have the small holes.

The oil fills the pores in the bushes using capillary action, it climbs up the the bush as long as the bottom of the bush is in contact with oiil.


Capillary action is the ability of a liquid to flow in narrow spaces, climbing upwards against gravity due to adhesion (liquid sticking to the container walls) and cohesion (liquid sticking to itself), combined with surface tension, allowing it to "climb" through porous materials like paper towels or plant roots, essential for plants to transport water. The smaller the space (capillary), the higher the liquid climbs.

I have one of these vintage grease or oil hand pumps, I also had some omala 220 oil at the time, it is absolutely the best thing I've ever used for the swing arm, I put my oil in it.

I don't have trouble with the swingarm oil leaking, but my experience is with bikes I've built. Here are some things I do that I think cause them not to leak.
1) Cradles are always blasted clean and never powder coated.
2) The area where the o-Rings or later-style seals will touch the cradle are perfectly smooth or the cradle is not used.
3) Before masking for paint the rear edge of the cradle where the o-Rings or new-style seals will be pushed into place are rounded over and made very smooth (beveled if you like).
4) When masking, I want as little bare metal as possible showing once the swingarm is in place. This prevents rust from creeping under the seal. I mask the area, put in a spindle and original style seal plate and cut around it.
5) The oil nipples supplied for a while were really grease zerks and the threaded portion was WAY too long. The caused the timing side end cap to not be able to sit properly on its o-Ring and it ensured a leak. AN has fixed their part of this - no idea about others. The too long fitting can be used but it requires 3 washers to space it out properly.
6) When putting the bushings and dust covers (original setup) I use a thin smear of RTV between the bushing and cover to prevent weeping at that point and I use new covers if the old ones are no flat and perfect. Also, if there is paint/powder coat on the edge where the cover or new-style seal will sit, it can cause weeping there and it needs to at least be made smooth if not complete removed.
7) If the swingarm is powder coated or too much paint is used, or there is paint/powder coat on the edge that the O-rings will not sit in their groove properly and therefore the endcaps will not be properly sealed causing leaks.
8) If the spindle bore in the cradle is wallowed out and the swingarm can twist in the cradle, it's only a matter of time before the o-Rings or new-style seals will be worn and leak. I'm not a fan of Kegler clamps "just because", but in the absence of a good cradle, I install them using parts from McMaster-Carr.

In other words, lots of root causes of leaks, all I know of are preventable.

At this point, I have no solid opinion on the O-rings verses new-style seal. The O-ring version seems more robust to me, but also more likely to leak if either the cradle or swing arm dimensions are off.

An experiment that coming is x-Rings. Most (all?) O-rings sizes also come in x-rings. For instance, the 6 O-rings (06-1900) specified for the fork ears are easier to work with in the x-ring version.

Shelby-Right said:

I have one of these vintage grease or oil hand pumps, I also had some omala 220 oil at the time, it is absolutely the best thing I've ever used for the swing arm, I put my oil in it. View attachment 123436

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I have one of those, but I use it with grease for the other grease points on the Commando (rear hub brake cam, foot brake lever pivot), my Velocette (swing arm bushes) and my classic mini (suspension ball joints and rear wheel swing arms).

I use this lumax one for commando SA oil:

One of the problems with the O ring is that oil can leak around it on two sides.

Walridge sells 1/2 litre bottles of 140w swing arm oil for $15 Canadian , enough to last a lifetime.

Andy Higham said:

I just had a thought looking at the last photo.
If the centre locking bolt was hollow and a pipe attached to a clear plastic reservoir under the seat, the oil could be observed and topped up easily

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this is what i did

Andy Higham said:

I just had a thought looking at the last photo.
If the centre locking bolt was hollow and a pipe attached to a clear plastic reservoir under the seat, the oil could be observed and topped up easily

Click to expand...

L.A.B. said:

One of the problems with the O ring is that oil can leak around it on two sides.

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I don't think the o-rings have quite enough preload, like the cups need to be shimmed in. 010" each side before installation, maybe some bikes have a stack up of tolerance that makes them looser.?

Andy Higham said:

I just had a thought looking at the last photo.
If the centre locking bolt was hollow and a pipe attached to a clear plastic reservoir under the seat, the oil could be observed and topped up easily

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Why not feed it from the factory-installed oil leak (chain oiler)?

Seriously, what could it hurt?

grandpaul said:

Why not feed it from the factory-installed oil leak (chain oiler)?

Seriously, what could it hurt?

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That would work just fine for its intended purpose, lubricating the swing arm bushes. However, the slight amount of oil weeping out would send the polishing cloth brigade crying and clucking , because unfortunately, too many people feel that oil equals filth.
So long as it's not leaving a big puddle on the floor Machinery needs oil to stay lubed.

JMWO

I use 30 wt oil that I dribble in via the bolt fitting at the top center of the swing arm every year or two.

One "fun " experience I had back in the day was using a standard grease gun that I put oil in to inject via the OEM fitting. That lever on a case gun can exert considerable pressure and I wasn't really thinking. I blew the fitting off the far side of the swing arm when that long, skinny screw stripped out of the fitting due to the pressure. Had to remove the chain case to make the repair. Be careful with grease guns!

The above post has made me think. Using a grease gun or oil can to pump oil into the pin cavity will cause a pressure build up that could cause the oil to be pushed out past the seals.
If the oil is fed from a reservoir by gravity, as the oil is consumed/leaks the cavity will be filled without pressurising the seals

Andy Higham said:

The above post has made me think. Using a grease gun or oil can to pump oil into the pin cavity will cause a pressure build up that could cause the oil to be pushed out past the seals.
If the oil is fed from a reservoir by gravity, as the oil is consumed/leaks the cavity will be filled without pressurising the seals

Click to expand...

I have blocked of the nipple so remove it and add the lube via a syringe

Andy Higham said:

The above post has made me think. Using a grease gun or oil can to pump oil into the pin cavity will cause a pressure build up that could cause the oil to be pushed out past the seals.
If the oil is fed from a reservoir by gravity, as the oil is consumed/leaks the cavity will be filled without pressurising the seals

Click to expand...

I just remove the pin retaining bolt on the top of the swing arm and pump oil in through the fitting until it comes out the top. No chance for a pressure build up.