Trans lube Question

Hello,
I don't want to start another layshaft bearing thread.
I'm specifically looking to hear from riders such as Les and Dave etc...
who have used the 6203TB c-3 phenolic resin caged layshft bearing as to what lube they use?
FAG bulletin cautions using EP based lubes w/ these cages.
I have not read or found any reports of cage failures as a result of using EP lubes.
What's my options or it doesn't matter.
Thanks,
Marshal

Marshall I doubt I have that special bearing you refer to in your post, but I have had the same layshaft bearing in my bike since I bought it in 2000. I don't know if it was even changed when the PO rebuilt it, but my point is I use whatever off the shelf tranny/gear oil there is availabe at auto zone or walmart and buy the heaviest weight. I have over 20k on the thing in my possession and god only knows prior to me. I don't think it matters a bit. Plus I rarely change the oil in the transmission so I don't believe that is a real issue either. I personally think the failures are more due how much people hammer on their bikes and possibly poor quality bearings, but that's just an opinion.

MarshalNorton said:

FAG bulletin cautions using EP based lubes w/ these cages.
I have not read or found any reports of cage failures as a result of using EP lubes.

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I generally use synthetic GL4 gear oil these days.
But your comments prompted me to do some searching, and I found a FAG pdf document which does give a warning that gear oil additives can reduce the service life of polyamide cage bearings but my not be relevant to "textile-laminated phenolic resin" cages.

http://www.basco.com.pe/Catalogo%20FAG/ ... terial.pdf

However, the rate of cage deterioration appears be directly linked to the operating temperature of the bearing, and increased constant running temperatures and/or 'old' contaminated oil will shorten the service life of the bearing.
If the document data is reasonably accurate (and if I've understood it correctly) then - for-instance, for a polyamide cage bearing running at a CONSTANT TEMPERATURE of 100°C / 212°F should have a service life of around 10,000 hours (for hypoid gear oil) and 24,000 hours (for gear oil). I'm not sure what the layshaft bearing running temperature would be likely to reach under normal conditions, but I doubt it usually gets as high as 100°C/212°F, unless somebody knows different?

According to the information, lowering the constant operating temperature considerably extends polyamide cage bearing service life and, although the lines go off the graph, running at a constant operating temperature of say, 70°C /158°F suggests a bearing service life of around 80,000-100,000 hours, so I'm not going to worry, but if in doubt, then I suggest changing the bearing every 10 years or so.

This is very similar to vinylresin in gas tanks resisting about everything until about boiling hot then decays with various solvents.

Thinner oil carries away more heat than thicker. I've done my experiments and will stick with ATF in my hi rev lower gear Peel but normal grade in my normal Combat that gets its highest speed loads in 4th, so sleeve/main shaft locked up and nothing to lube in between them, cause it sure ain't getting in there if spun up much.

Keep in mind the subject of this thread is chemical based. Same should be main reason to change even gear box oil more than once a decade. Its corrosive acids from condensation that most pit and decay the hardened surfaces than plain ole wear and tear. Its worth while to do an early lube change after a new gear box breakin.

Riders,
thanks you for your responses.
Les, that was what I was referring to.
I stumbled upon that same bulletin and was wondering if I should switch out from EP 85/90wt?
You are right heat and break down cause deterioration of resign cages.
I think I'm going with the red line GL5 or 4 as you have used. Difference?
ATF, I've heard used in the primary but not in the trans case?
Hobot, do you mean using in your trans?
The other rider who suggested off the shelf 90 wt from Walmart etc....
You probably have a steel or brass caged bearing which would not be affected by EP type additives.
20,000 on the bearing, hopefully it has been replaced since leaving Wolverhampton :shock:
If so no problem but w/o any proof it is probably on borrowed time.
It's like an Al-qaeda bearing liable to explode w/o warning :mrgreen:
Marshal

I don't know if ATF is safe for composite cages. Mine were all brass or such.
i think gb get half its heat by its internal friction and other half via engine cradle.
Hottest I ever got gb was not boiling but could not hold hand but seconds so guess like 170'F. Low speed gears need thicker oil, hi speed thinner.

ATF has long been used in AMC gear boxes no problemo, not just me, who after seeing that gear lube was not up to Peel screaming the sleeve shaft in lower gears, was very relieved I was not experimenting, just using proven alternative to 90wt. Don't be so worried, 90wt is closer to 30 grade engine oil. So ATF ain't all that dramatic a change, but was enough to get in and carry off my heat so no more carbonized metal ceramic slag developed. If not spending much time near red line in lower gears about any grade thick or thin is fine. Engine usually leaks less than 1' or gb, so nice to get idea of where to look first for the new mess. in Peel I've had Dextron II in forks, primary and gb all at once. Since then I now like power steering fluid in forks better. Old Ford Type F ATF had friction modifiers for the clutch bands so may be better for clutch plates.

ATF is very good gear lube. Automatic transmissions have more gears in them than most standard transmissions. Many car standard transmissions use ATF including Mercedes since the fifties. Jim

Jim,
would it be safe to use ATF in the AMC gearbox with a phenolic resign cage layshaft bearing?
Hobot did not think it was safe.
Thanks,
Marshal

I have had several cars that specd ATF for the manual tranny. OTOH, though I'd LIKE to think ATF would be fine, since I KNOW that gear oil is specd for the Commando and ATF has never been, I don't think I'd make such a change without some long-term, decent-sized data base, with teardowns/measurements supporting it.

I realize someone could make the argument that they (Norton or AMC) just never bothered to test ATF because there was no real reason to do so and that if they had, it would be fine. That may be true but since they didn't, there is no data.

Don't get me wrong, I'd RATHER use ATF than gear oil but I don't care to be the beta tester.

Marshall,
Phenylene oxide or noryl as used in bearing cages is considered marginal when used with lubes containing PAOs [less risk with diester] such as most synthetic lubricants. Cracking can be the result. It is commonly used anyway and the risk is small. I have seen many cracked noryl cages but failure is uncommon. Conventional ATF and most gear lubes are safe however some gear lubes are not good for bronze bushings.

Personally I use bronze cages and synthetic ATF. Jim

Mike
My Commando has been beta tested the last 80,000 miles or so with atf. Probably time for a rebuild.
By the way many over the road trucks use ATF in there HD gearboxes also. Jim

OK, Jim...when she goes back together, ATF it is! If it blows up in next year's LaCarrera PanAmericana (hope to be the third Commando in the race), I'll be sending you a nasty note!

Oh, by the way, will you have E-start ready by then or will I be kick starting for the whole race?

Race bikes don't need no stinking starter.

Jim,
I assume you probably have a clutch rod seal on your bike. Any comments on running ATF without the seal? More creep on the rod, less? Maybe it doesn't bother clutch plates as much as gear oil? I have noted that some run ATF in the primary anyway.

Russ

I do have clutch rod seals on my bikes. I have always machined the end of the mainshaft for a small metal cased lip seal.
However back when I ran chain drives I always used atf in the chaincase because it didn't seem to make the clutch as sticky as motor oil. Jim

Regular old Dexron?

Regular ole Dextron II. Other variety may or may not work as well or maybe better.

Yes Dexron. Or Dexron synthetic if you want to splurge.

I'm in Mexico; they never heard of Dexron synthetic!

MexicoMike said:

I'm in Mexico; they never heard of Dexron synthetic!

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Your probably lucky.