Oil for gearbox

[morris]

Dug up an old thread treating gearbox oils, but couldn't find a straight answer to my problem in it, so I'm bringing the topic up again.

I am using Penrite's Classic light 20/60 in my engine, and also in my gearbox (mainly because it's easy to have the same oil in both).
Problem now is that it foams in the gearbox after I rebuilt it (didn't notice it before the rebuild).
Now, I like a bit of foam on my beer but not in the gearbox so I want to try Penrite's Gear box 30 or 40 (like to stick with the Penrite because there's a dealer just aroud the corner)
Anybody got any experience/suggestions? (particularly regarding the foaming)

Thanks.

[trevinoz]

Morris,
                  I use a dedicated gear oil. E.P. 85, from memory.
Viscosity is about the same as 30, so I'm told.

Trev.

[bsa-bill]

yes I agree with Trev, gearbox and hydraulic oil have anti foam stuff in them so I'd go the EP way, although BSA recommended 40 engine oil if I recall correctly, but that was then

many years ago I asked a similar question and was amazed that the viscosity grades for engine and gearbox were different, would have thought it an advantage to have a common marker but there you go

[Sparky]

In the same BSA workshop manual, I found three references to gearbox oil; 40 wt,  50 wt, and 20W/50 multigrade.  No wonder it's a subject of some debate.  I used straight 50W in my A10 for years, and during a recent rebuild I did notice a bit of scoring on the output end of the main shaft.  I now run Lucas 80-90 gear oil which I feel has superior antiwear, anticorrosion, and antifoam properties.  It shifts just as smoothly as it ever did.

[Ethelred]

Engine oils are formulated to resist pressure, e.g. in the big ends, whereas gear oils are designed to resist sheer caused by gears. However gear oils can cause problems with synchromesh so are usually only used in rwd differentials nowadays. But gear oil EP80/90 is just the job for our gearboxes.

[a101960]

I am using Penrite's Classic light 20/60 in my engine, and also in my gearbox (mainly because it's easy to have the same oil in both).
Problem now is that it foams in the gearbox after I rebuilt it (didn't notice it before the rebuild).

Thats an interesting point. If my memory serves me correctly the first 20/50 multigrade oil was Duckhams or at least it was in the UK, and although it has been said that Q 20/50 was formulated for motorcycle applications it was one of the oils recomended by British Leyland for their front wheel drive cars where the gearbox was located in the sump. I used it in my Mini Cooper without any problems, and also in my Austin Maxi. Having said that it is almost certainly the case that the Penrite additive formula is not the same as Duckhams. I also used Castrols GTX in the days when it was a 20/50 multigrade. On the topic of oil I use Halfords 20/50 classic oil in my RGS, and I noticed that Halfords claim that it is a low detergent oil. I do not seem to remember either Q 20/50 or GTX being marketed as low detergent oils. The reason that I mention this is because Halfords claim that their classic 20/50 is suitable for older vechiles because it is a low detergent oil that replicates the oils used in the sixties and seventies. Odd that because all the cars of that era had full flow oil filters on the input line. As a general observation It would appear that both Australia and the US have a far wider range of oils to choose from than we do in the UK. As an example 20/50 air cooled engine fully synthetic oil is not available in the UK, or if it is the sale and distribution of it is a well kept secret.

John

[bsa-bill]

it has been said that Q 20/50 was formulated for motorcycle applications i

Hi John, on another list many moons ago one of the contributes worked in the oil industry (sadly he is no longer with us), it was in one of his post (in the midst of an oil debate where 20/50 was being denigrated) that he informed the list that Duckhams 20/50 had been designed for air cooled engines, that covers but is not exclusive to motorcycles engines.
Detergent oils were around early sixties and maybe before and were the norm for diesel engines in tractors,also around the same time in agriculture came "universal" oil used in engine, gearbox and hydraulics on farm tractors, so it must have had a concoction of additives in it but widely used.
Also interesting was the myth ( I think) that Duckhams prevented the build up of sludge in the mini rocker box

[morris]

Sent an enquiry to Penrite, and the answer I got was that there was maybe some dirt/contamination causing the oil to foam.
This set me thinking that it may well be some residue of the degreaser I used to clean the parts and the internals of the box.
I have drained and refilled with fresh oil, so fingers crossed.....

Penrite also said that the 20/60 classic light, and the straight gearbox 30 are very similar oils, and where not sure that changing the type of oil would solve the problem.

To be continued......

[muskrat]

G'day morris, was the foam a white-ish colour? Could have been condensation (water). I have noticed this in a few bikes that only do short runs. They don't get hot enough to evaporate the condensation and it ends up emulsafying (spel check not working) the oil into white froth.
Cheers

[Motoanimal]

I used it in my Mini Cooper without any problems, and also in my Austin Maxi.

I never thought that I would see the day that anyone admitted to owning an Austin Maxi!  

[a101960]

I never thought that I would see the day that anyone admitted to owning an Austin Maxi!

Oh dear, Looks like Jeremy Clarkeson has joined the site. Motoramimal is a very apt user name Jeremy.

[bsa-bill]

I recall one our many managers having one and one of his son's sitting in it rocking it on the spot using it's hydrolastic suspension and the handbrake, his previous car was a sporty BMW, Austin/Morris had some excellent salesmen up this end of the country 

[Motoanimal]

Oh dear, Looks like Jeremy Clarkeson has joined the site. Motoramimal is a very apt user name Jeremy.

I actually owned a Austin 1100, so perhaps I just better shut up, eh!  

Don't forget that Africa part 2 is starring me on Top Gear on Sunday, don't miss it!  

[morris]

G'day morris, was the foam a white-ish colour? Could have been condensation (water). I have noticed this in a few bikes that only do short runs. They don't get hot enough to evaporate the condensation and it ends up emulsafying (spel check not working) the oil into white froth.
Cheers

Thanks Musky, haven't thought of that, may well be possible. We are having cold freezing nights and sunshine during the day for the moment.
A couple of days ago I found the bike was all covered in condensation. On the outside of the tank I could even see the level of petrol in the tank!
I was going to take her for a big ride next Sunday, but there's snow expected over here, so that 'll have to wait.
Keep you informed.

[bsa-bill]

I actually owned a Austin 1100, so perhaps I just better shut up, eh!

Well it look like it's "coming out" time so yes I to had an 1100 and several Mini's, also can I have several other case's taken into consideration of Maestros, Rovers and an MG

I'm still having counselling for the ownership of the Reliant Regal