Swing Arm Play

splatt · Dec 19, 2012

hobot said:
Btw 140 grade gear lube = 40-50 grade engine oil. Thickest engine oil like for pre-war Harleys is 70 grade or weight, though the W means Winter grade not weight. Industrial cutting oil can be in this warm grease like thickness too.

sae 50 engine oil only =90 gear oil, 70 would be correct or use iso 460 =sae150 gear oil, iso 680= about sae 190 gear oil

Rohan · Dec 19, 2012

Have you seen 140 gear oil ?

Its WAY WAY beyond 50 weight engine oil.

50 wt engine oil and 90 wt gear oil are supposed to be the same viscosity.
Only numbered differently, so folks don't use em in the wrong application...

pete.v · Dec 19, 2012

I use 85w140 and works great. We're just lubing the darn spindle here. Straight 140 is not readily available.

As far as application, I use a grease gun. Clean out the grease from the pumper and pump some spirits through the end. You need to save an old used tube or get a new cartridge of choice and push it out into a marg tub for axle grease supply and wipe it out. Pull the plunger back on the grease gun and lock it in place. Place the used tube all the way down in the bay and put about 8oz of chosen oil(more than enough). Screw the pumper on, release the plunger. Loosen the center retaining screw on your "pre" mkiii spindles till it's just about out and fill er up till it oozes from the screw. Pump the unused portion back into the bottle and save for next time.

You'll have to ask LAB about MKIII units.

Hobot · Dec 19, 2012

One should use the thickest stuff you can stuff around the spindle not for the lube factor just the stick around a while factor. The extra large numbers of gear lube grading does not reflect the amount of slight extra thickness over motor oil with half the grade number rating. 90 gear lube is about like 50 motor and 140 is about like 60 motor oil See what ya make of this if ya care. I like any the motor honeys like STP or Lucas oil treatment myself.

https://www.opieoils.co.uk/pdfs/tech-ar ... ations.pdf

splatt · Dec 20, 2012

85w-140 will behave like a 85w oil in a swing arm application

rpatton · Dec 20, 2012

rvich said:
The spindle was a nice tight fit until I drove the bushes out with a similar sized socket. The process compressed the end of the bush enough that it would no longer slide on to the spindle and would require honing if it were to be reused.

Russ

Russ, Just for future reference, this would be a great instance to use the old 'threaded rod and appropriately sized socket technique' in place of a press. You can use: nut-washer-socket ----------flat thing-washer-nut
to pull things out and put them back without hitting them. Steering stem bearings, wheel bearings,and other bearings and bushings are some good applications. Use the fine thread 3/8" with never seize.

rpatton · Dec 20, 2012

kettle738 said:
Well, I've just fitted the new bushes to the swinging arm, and to my total amazement the spindle is now a nice tight push fit, the slop has disappeared.

Mick.......kettle738.

It's great that it came out the well. When a bushing or an outer race gets pressed into something with an interference fit then there will be some crush, just like there's some stretch on inner races pressed onto shafts. The first time I came up against it was when I had an upper fork bush that fit the stanchion fine till assembly time. Locked it up very solidly.

JRD · Dec 20, 2012

what needs to be understood is that those bushings are made (or should be made) of sintered bronze , not from solid bronze. This explains why they absorb oil but also why they are prone to distord when put in place.

see http://www.lm-tarbell.com/machining_sintered_bronze.htm about how this should be manufactured and machined

Swing Arm Play

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