Engine oil queries

[ncfcdexta]

I am going to replace the oil in the engine, transmission and rear axle. I have looked at the sticky thread regarding the correct grades to use etc.

My query is: Is it ok to use modern multi grade oils with detergents / additives in them? I have heard that using these modern oils can actually do more harm than good in terms of the cleaning effect they have.

Please could someone clear this up for me? I would also be interested in hearing what oils you all use.

Many thanks.

[YorkshireDextaMan]

Quite an easy choice really. An item like this on Ebay 300657136742 You will need about 37 lts. dont know how you can get to that figure exactly but if you went for 35ltr you wont be far out. if you can get it cheaper thats good, but that stuff will do the trick

[Wee59dexta]

Hi mate i use 15w40 semi synthetic. Probably aint the correct oil but i find it good enough. also its not to thin when cold

[Brian]

This is what I would use. I am moving my "fleet" onto this.

http://www.morrislubricantsonline.co.uk ... +Motor+Oil

[YorkshireDextaMan]

You may well be right there Brian, allthough i would think that if the oil that i pointed out was good enough to spin a turbocharger in a diesel engine at 10.000 RPM it would be more than good enough in a Dexta at 1,500 RPM. Ofcourse, the fellas query was about a Dexta application, But i suppose if one was to cover a fleet of vehicles and price was no object then Morriss have the edge,




Dextas, The older they get ,the more care they need, Jim

[Tubal Cain]

Just checked the oil capacities in the operator's handbook.

Engine 7.25 litres

Gearbox 13.07 litres

Rear axle 19.32 litres

Total 39.64 litres, that is without the air filter and steering box.

Gerald

[GERRY]

hi before i rebuilt the engine on my dexta iwould use 15/40 and it seem to do the job , this was mainly because
ijust could not find any 20/30 or 30 oil, after rebuilt i used 15/40 but it started to blow oil out exhust
this was probley because of lack of use, any way i changed to morris 30w which i was able to sorce although was a fair bit away from me . ihave been useing this since with good results so i go for morris if you can get it Gerry

[Brian]

Sounds silly but the oil can be too good. Most modern oils are rated near Series 3 which can be used in a turbo engine but the older tractors like Dextas were designed for a Series 1 oil.

As I have said before, it is only my personal opinion and based on my observation of my "fleet", I used a good quality 15/40W oil for many years. Since changing to a 20/50W the oil pressure on Henrietta has increased and now stays around 20 psi even when very hot, something it did not do on 15/40W. Also, on Nuffy since changing, a timing cover seal oil leak has stopped and the oil pressure is around 50-60 psi.

My oil supplier did not recommend any form of synthetic oil. He says you can always tell old tractors that are run on it by the amount that lies on the floor beneath them. Now I can only passing on his advice to me as I have had no experience of a synthetic type in the tractors, however Ann's car runs on synthetic and is no problem at all. However the cost per litre is astronomical.

All my diesel cars have been run on Castrol GTX and I have always got good engine life from them.

[ncfcdexta]

WOW!

Thank you for all your replies. I had no idea how much oil costs and how hard it is to find the right stuff.

As I wont be working her too hard or often, how frequently would one change the oil? As recommended by the manual or less frequently?

Thanks again
NCFCDEXTA

[russelm]

I would just add that synthetic oil is no more likely to leak than mineral oil. Its benefits are longer life and much greater viscosity stability (hence longer life and the need to e it in cars with stupidly long service intervals). The engines have been designed to create oil pressure based on the grade and the grade alone.

The major thing that most modern oils do have is detergents, its these that are more likely to cause issue as they gently clean the internals and make the wear of the engine start to show. Be aware that both mineral, semi and synthetic oil can have these in (something that the Morris stuff often does not have as we use it in the diesel loco at 600 litres a change, although the ring free grades have some).

For me, on a newly re-built engine I see no probelm with the modern oils and the long term benefits will show through in time. On an engine that is worn or has been broken in on a basic oil then a change may result in issues appearing.

I ahev to say, I dont use Castrol GTX anymore as its probably about the worst of the 'general' oils available today (i used to 20 years ago) and suffers badly with shear and has a habit of mayo build up due to condensation in the crank case.

[Jerry Coles]

Using a Detergent based oil in an old engine will 'wash out' all the accumulated carbon/gunge in the engine which has probably been helping to maintain seals etc.
On a new engine it probably won't make much difference so you can search for a more available/priced oil.
The Army moved to a detegent grade oil for their vehicles in the 60's and suffered a huge amount of engine failures in a very short time (no sophisticated engines with turbo's, EMU's etc then.
Jerry
Bath
UK