Oil Question

[RoyC]

I have purchased 4L of Mobil 1 15W-50 Racing 4T synthetic motorcycle oil for my 1958 A7ss.
My question is :- Can I also use this same oil in my primary chain case or will it not work with the clutch (6 spring) ?
http://www.ebay.co.uk/itm/322388335677?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
Thanks.

P.S. I have just removed the primary cover and the fluid that came out has the same colour as automatic transmission fluid.

Just found the answer - use mineral engine oil in primary chain case.

[RichardL]

First, I think it's safe to say that most of us are using ATF in the primary case, though, it's not what was originally specified.

As for the Mobil Racing 4T, I think Mobil has put out some confusing information about this. If you look at the 10W-40 version, their advertising says it's specifically designed for wet clutches, but the 15w-50 does not say this. In fact, I found this post on another forum:  http://www.triumphrat.net/sprint-forum/99074-reply-from-mobil-on-their-15w-50-a.html . In this link, Mobil is suggesting against using the 15w-50 for wet clutches and goes on to suggest using their V-twin oil, instead.

Also, for 10w-40, you can find a PPM number for zinc (1200), whereas I was unable to find a number for the 15w-50. By my understanding, with flat(tish) tappets like ours, the more zinc the better. I use Valvoline 20w50 VR1 Racing Oil with 1300 PPM zinc. As it turns to out, the V-Twin oil has about 1800 PPM zinc, so I'm going to look into that, but continue to use ATF in the primary.

Richard L.

[Greybeard]

I took advice from the Trusties on this forum and put ATF in my primary case, EP90 in the G'box and I use single grade SAE 40 in the engine, along with a clean sludge trap and a return line filter. Using different oils in each area at least narrows down leak detection.

[RoyC]

First, I think it's safe to say that most of us are using ATF in the primary case, though, it's not what was originally specified.

As for the Mobil Racing 4T, I think Mobil has put out some confusing information about this. If you look at the 10W-40 version, their advertising says it's specifically designed for wet clutches, but the 15w-50 does not say this. In fact, I found this post on another forum:  http://www.triumphrat.net/sprint-forum/99074-reply-from-mobil-on-their-15w-50-a.html . In this link, Mobil is suggesting against using the 15w-50 for wet clutches and goes on to suggest using their V-twin oil, instead.

Also, for 10w-40, you can find a PPM number for zinc (1200), whereas I was unable to find a number for the 15w-50. By my understanding, with flat(tish) tappets like ours, the more zinc the better. I use Valvoline 20w50 VR1 Racing Oil with 1300 PPM zinc. As it turns to out, the V-Twin oil has about 1800 PPM zinc, so I'm going to look into that, but continue to use ATF in the primary.

Richard L.

Is this the oil that would be better in my engine - http://www.ebay.co.uk/itm/Silkolene-V-TWIN-20W-50-Mineral-Based-Bike-20W50-4T-Engine-Oil-3-x-1-Litre-3L-/171790272100?hash=item27ff7f8664:g:NEwAAOSwoydWqjVn ?

I have loads of ATF so will use that in my primary case.

[JulianS]

There are many different specifications of ATF due to the various needs of different transmission designs.

Not all may be suitable for our clutches.

I used "type F" (a Ford spec from some years back) for several years but have now gone back to  20 SAE.

[RoyC]

There are many different specifications of ATF due to the various needs of different transmission designs.

Not all may be suitable for our clutches.

I used "type F" (a Ford spec from some years back) for several years but have now gone back to  20 SAE.

I have some type F that I used to put in my Lincoln Continental (Ford) so I will use that.

Thank you all for stopping me from cocking my clutch up.

[RichardL]

Roy,

I won't be telling you which one to use. Others here may be more comfortable doing so, but I thought this post was an interesting description of the various ATFs from which one could form an educated opinion. http://www.v-twinforum.com/forums/engine-oils-lubrication/136694-some-observations-atf.html#/topics/136694?page=1

In any case, I think you can always change to something else if you think there is room for improvement.

Richard  L.

Ric

[RoyC]

Thanks for that Richard.
I have type F and Dexron so have a choice.
I may give the Dexron a go first.

[KiwiGF]

As well as ATF I think lawnmower oil is a popular choice for the primary, I use Briggs and Stratton sae 30, and being red, you can like ATF see when it's leaking out 

My A10 leaked ATF worse than when filled with the sae 30, I think because it's thinner, I would not dare put ATF in my B31, its thin steel cases look like they will leak like a sieve 

I used the 4T oils on several modern bikes with wet clutches with no problems, I did not look into it in detail but assumed it was specifically made for use with wet clutches?

I used castrol gtx in my big Suzuki v twin once, and sure enough the clutch slipped until I changed the oil to a motorbike grade, silly me 

[bikerbob]

I have used straight 20 grade fork oil for 20 years in various BSA bikes with no problems the reason for using it was I was advised to use it 20 years ago because it does not emulsify like some other oils.

[duTch]

 I've wondered about the grades and functionality of ATF grades since I tried mixing it 50/50 with acetone as a penetrator after suggestions by olev? and MG, but it separated immediately...

 Having said that, my most recent use is a Penrite 'Top Up' (a bit of a 'multi-grade' ATF ?), as was the best option in a hurry, but can't say it's good or not as the primary is still goin' around, but I know it still leaks.

 ATF is also recommended for use as fork oil in A65's and Moto Gutzzi, so I do that

[RoyC]

I took advice from the Trusties on this forum and put ATF in my primary case, EP90 in the G'box and I use single grade SAE 40 in the engine, along with a clean sludge trap and a return line filter. Using different oils in each area at least narrows down leak detection.

Are you sure that you use EP90 and not EP80 in the G'box?
EP90 is back axle oil, EP80 is normally G'box oil.

[Greybeard]

I took advice from the Trusties....
...EP90 in the G'box..

Are you sure that you use EP90 and not EP80 in the G'box?
EP90 is back axle oil, EP80 is normally G'box oil.

You might be right; I was working from memory; I'll check the bottle tomorrow.

[JulianS]

Worth looking at the Morris website. Lots of useful information on oils in classic vehicles, including low detergent engine oils to suit the simple filtration systems fitted as standard.


https://www.morrislubricants.co.uk/products/classsteam/classic-engine-oils.html


 

[Black Sheep]

I use tractor universal 10W-30 in my primary chaincase and forks (and tractors). Although it's primarily a diesel engine oil, it is also suitable for hydraulics and for oil bath brakes as found in tractors. Works a treat for me. And it's cheap.