MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG Midget and Sprite Technical - Synthetic gearbox oil

Gearbox can be a little notchy, ironically when hot, so am contemplating using Westway 79w/90 synthetic transmission oil.

They say

'It offers high levels of performance when compared to straight mineral oil whilst being compatible with mineral oils which enables it to be simply used as a replacement product on a drain and fill basis.

This is a GL-4 and GL-5 Specification synthetic gear oil meaning it is safe for use where yellow metals are present. It contains a buffered sulphur EP additive which helps protect yellow metals found in some gear boxes.'

In the past I've used 20w 50 mineral engine oil which admittedly isn't a straight mineral oi, so the question is has anyone any experience of this oil?
IIRC some people have used synthetic oils in their gearboxes (Nigel?) so any positive/negative experiences welcomed?



Jeremy MkIII

Jeremy
Don't know if this will help at all but interesting anyway-
A friend has been using his E type jag in speed events for years and uses the recomended 20/30 oil in the box
It's a fairly clunky old box at the best of times but worse when hot---like yours
By chance talking to some other jag guys at the local and mentioned it's clunkyness and straight away it was- what oil are you running, told them 20/30 and the comment was no that won't work, it has to be a straight 'gear oil' and said give penrite fleet gear 30 a go---Willing to try anything, sourced some fleet gear 30 and bingo! different car with smooth gearchanges cold and hot
worked in the jag---might be worth a try--?
willy
William Revit

Jeremy,
I couldn't get the links to work on their website including their eBay shop which the link said didn't exist so I couldn't get info on the product.

To keep it simple don't worry about, often only marketing, terms like semi-synthetic or synthetic, a good quality oil is a good quality oil, a high quality mineral oil is probably better than a low quality 'synthetic oil'.

Again keeping it simple for a transmission oil you want a GL4 spec rather than GL4/5.

Some use a monograde engine oil very happily.

Most use 20w50 engine oil very happily.

You could perhaps consider a different multigrade or a better quality 20w50 than you're using now.

The Castrol Syntrans Multivehicle 75W-90 Fully Synthetic MTF has been used with success on some Ford Type 9 gearboxes to overcome some notchiness particularly in very cold weather.

Thing is a thorough change of gearbox oil to any type might help a little and perhaps a better quality and/or type might help a little more but if you have wear or other issues the oil can't do miracles, but might still help.

What make, model weight of oil is in your gearbox now?

How long has it been in the box?

Did you last just do a drain & refill?

Nigel Atkins

chart for comparisons of various weights -


Nigel Atkins

Back again, neighbours are having BT/England telecommunication problems . . .

Jeremy,
I'm assuming you've checked the current oil level in your gearbox, just semi-related what oil are you using in the engine?

Are you sure it's a gearbox rather clutch issue?

Does it easy if you do something like double-declutch/staged changes?

Is the notchiness on all gears when hot?

What colour are my eyes?
Nigel Atkins

Thanks Willy and Nigel,

Willy it hadn't crossed my mind to use a straight oil, that's food for thought.
I just happen to have just over 1.5 litres left over of the Westway oil from filling a VW trans-axle which has resulted in an easier gear change - mind you there was only 2 litres of unknown vintage oil when it was drained and was wondering if it would work as well in the midget, hence the request for others' experiences.

Nigel,
thanks for the info and chart, although you may need to explain it to me...
To answer your questions

1) Halfords Classic 20w 50
2) 10 years
3) Yes
4) Yes, it's full and sUnipart High Performance 20w/50 which I'm trying out
5) No
6) Also no
7) Yes
8) Left is blue, right is green
Jeremy MkIII

Uhmm, sounds possibly more like g/box than clutch on limited info and if your present g/box oil is 10 years old then certainly a thorough change of oil might help and do no harm - subject to the muck/crud in the oil and g/box not being the only thing holding it together. :)

On the MGBs with overdrive the service interval for the engine oil in the g/box and o/d is 24 months or 24k-miles whichever is the sooner, engine oil will be passed its best sooner than transmission oil in the gearbox so I think 10 years isn't too soon to change the engine oil in your gearbox.

The thing is get out of your gearbox as much of the existing oil and muck/crud as possible so as to clean it as much as possible and also to not dilute the fresh oil with the old oil and muck/crud.

To do this you want to get your existing oil as warm/hot as possible then drain for a good while, say overnight.

To get a good flow you want to remove the filler/level plug first (this also checks you can get the plug out to refill with oil before you're left with an empty box you're not able to refill).

As a quick flush you could also, whilst the hot existing oil is down to dripping out, tip some fresh oil (warmed if you want) into the open filler hole to flow and flush straight out of the open drain hole hopefully cleaning and flushing out any residue crud/muck and existing oil.

Or you may want to fill the gearbox with a cheap oil and/or thinner oil to act as a cleaning flush of the gearbox whilst you drive the car with this oil in for a number of miles before thoroughly emptying it out as above then refilling with your chosen quality of oil for full use.

The chart is to show relative "thickness" of engine (crankcase) oils numbers, range against gear/transmission oil numbers, range - e.g. 30 (range) engine oil (when not knackered) is within in the range of 80 and 85 gear oils.

If you've got enough Halfords 20/50 to refill and pour flush your gearbox you could try that, or you could buy some cheap oil to use as a driving cleaning/flushing oil then refill with good stuff - just do thorough warm/hot and long drains on all oils to get as much oil/crud/muck residue out at every stage.

You know I can send you notes if wanted.

Totally wrong about my eyes, they're both very sexy, very dark brown.

Nigel Atkins

Other than the 1500 engine, all the other gearboxes are designed for 'engine' oil, with the later spec being 20W/50.

GL4 and particularly GL5 transmission oils, including synthetic ones, both contain 'EP' additives that will attack any 'yellow' metal components in the non-1500 gearbox, such as the synchro cones - get plenty of double declutching practice in, just in case!

Richard
Richard Wale

Cheers Nigel, ten years is a long time and it's just slipped by...
The mileage however is far, far less than it was when the car was being used by my wife as her daily driver.

That concerned me too Richard,
This oil was chosen because of its rating as a GL4 transmission oil which I understand is compatible with the softer yellow metals whereas GL5 is not unless it has the MT1 suffix.
My limited and very possibly completely wrong, understanding of oils, was that the added buffered sulphur EP additive, is designed to protect not attack, the yellow metals in my 1275 gearbox?
Jeremy MkIII

Jeremy,
your last post has turned everything around - you've got it, probably from the posts and threads of 'he who can not be mentioned' so also bear in mind the rebuke of the "added buffered sulphur EP additive" from an oil supplier that he who ect., found.

So - as you understand the risks, and for the facts, that Guy had (unknowingly at the time) used the GL5 Comma SX75-90 in his T9 for IIRC 40k-miles and I used Mobilube GL5 and currently Millers CRX GL5 after the email reply I got from Millers and posted here - you could try the Westway 79w/90 if you already have sufficient.

It's all a matter of believe and faith, some will say you have been able to use GL5 for a good number of years and others will say you can't, as with a lot of beliefs only time will tell but it could be too late by then.


Nigel Atkins

Indeed Nigel, what oil to use seems to be a complete can of worms whenever classic cars are discussed and just about everyone has a preference. There is just so much choice it becomes bewildering - analysis paralysis.

I'll probably try it and if doesn't make any difference then drain it, do as Willy has suggested and see how that goes.

Much like using unleaded fuel in a leaded cylinder head, I suspect it will take many years of relatively low mileage motoring before defects start to become apparent.
By then we'll have had to convert to electric to be able to use our cars and will only need 3rd gear if at all :)
Jeremy MkIII

Jeremy,

I posted some time ago about using newer tech oils in ribcases and received the usual 'BMC specified 20/50' and it worked for me/dad/grandad so why change.

Well I believe that oil tech has moved on a huge amount and that had BMC had some of the newer oils/additives they would have spec'd them !

I'm running Penrite gearbox oil GB30 - it is recommended for where 30SAE or 20/50 was spec'd and they note it is compatible with synchro cones and whitemetal bearings and is non EP and can be used with O/Ds.
My mileage is not very high currently but so far no problems and in the past I have had issues with wear including layshafts/bearings which a better oil may have reduced, so only time will tell.

R.



richard b

As I recall, it turned out that there were two groups of oils, both rated GL5 with one class that gobbled yellow metals, whist the other did not. Or so the claim went.
So in buying GL5 there is a risk, or at least you need to do more research. Whereas with a GL4 oil, you are safe.

Incidentally, that Comma oil that I used was what Burton Power recommended at one time, when Ford stopped selling their original and very expensive specified T9 oil!
GuyW

Jeremy - if Guy and Nigel have Ford T9 gearboxes (did I read previous posts correctly?) I would respectfully have thought their direct experience is not that useful for your situation. FWIW I've used Mobil1 (fully synthetic) 20/50 or 10/60 in my race s/cut ribcases for 15 years and haven't had any failures knowingly attributed to the oil.
David Smith

Guy, just for once (IIRC) it's you and not me that has remembered wrong, the recommend Comma oil was SX75-90 GL4 and you had installed GL5 at one time without realising for (IIRC) 40k-miles, you may then have went on to the GL4 but my memory has you first used the GL5.

I had Comma SX75-90 GL4 in my T9 from installation then switched to Mobilube GL5 and on to Castrol Syntrans Gl4 (as Mobil backed off the use of its GL5 in T9) both Mobilube and Castrol (and later Milers CRX) seemed to me and others to give better gear changes than the Comma and if I could ever get enough usage/mileage out of my T9 from other installer/garage problems I might find out if (more modern) GL5 might b*gger up the synchos - subject to the car, clutch or me not falling apart before then.

Nigel Atkins

Back to a basic question?

Jeremy, which gearbox are you using? The use of engine oil only relates to the original smoothcase and ribcase BMC boxes.

Richard
Richard Wale

Very likely true then Nigel. I don't have the empty oil bottles and rarely keep notes of this sort of thing. It's probably in the BBS archives somewhere, but that is a place I don't go as I have yet to work out how to find what I am seeking.
GuyW

David,
That's very interesting, when fully synthetic has been discussed before it is often noted that the old seals/scrolls etc are much more likely to leak with the modern synthetics - have you noted any increase in drips etc ?

Also do you have a seal conversion on the front plate/ first motion shaft ?

R.
richard b

Guy, I don't remember much but that I do remember, if I could remember key words I'd soon turn it up in the Archives and if my spelling and terminology was consistent I'd also be able to find my own threads and posts, but it isn't.

Richard, in Jeremy absence, to the best of my knowledge and memory (which isn't saying very much at all) Jeremy has the British Leyland one with 4 forward gears and no synchro on first.
Nigel Atkins

Yes Nigel is correct, it's the original BL 4 speed non syncro on 1st, gearbox which has about 110,000 under its belt.

Have always used a 20/50 oil but was thinking along the same lines as Richard B. Interestingly Richard you're the second person to suggest a 30w weight oil - Willy also suggested it. Thanks for the info

My understanding is that GL4 oils are ok for our gearboxes but GL5 are not, UNLESS they have an MT1 suffix?

I'm also confused about EB additives. Westway describe it as an added protection for yellow metals (as it contains sulphur I believe) but it seems from here that it may not be a good thing to have in your 4 speed gearbox - is it a bad thing then?

David thanks for the info on your use of fully synthetic oils and their lack of damage to your gearboxes!
Jeremy MkIII

Jeremy, my apologies.
I wasn't suggesting a GL5 oil for your car or meaning to confuse the issue. It was just that the conversation had veered off onto the use of GL4 vs GL5 oils in general.

When I was still using a 4 speed MOWOG box I used standard mineral 20/50 engine oil as originally specified. But I have no doubt that oil technology advances in the last 60 years must have come up with some thing rather better. But OTOH I have also read opinions that some modern synthetics can be too 'slippery' for best operation of older syncromeshes.
GuyW

Jeremy,
as with Richard and Willy recommending a 30 weight range oil if you have a look in the Archives you'll find previous threads and posts where this has been recommended by others by its use by them or others.

As you're probably not using your car during the colder parts of winter you probably don't need "thinner" oil than one in the 30 range.

If you look in the Archives you'll also find an exert from the letter he who etc. that goes into the GL5 and 'buffered sulphur EP additive which helps protect yellow metals found in some gear boxes' issue(s) basically the author, who it seems is in the industry selling oils, doesn't believe it.

Not all oils marketed as synthetics are the full fat type and then there are two types of synthetic, if you want to look into oil, like tyres, you'll find it's a lot more complicated than you'd think and clouded by commercial concerns and different testing methods and associations.


Nigel Atkins

Richard B - I was running the input shaft scroll seal on one box until about 4 years ago and used to get a bit of a dribble from the drain hole in the bellhousing but as it's always clean oil it does little harm or staining. Now I use Heathrow Transmissions who fit the modified front cover as standard and I now have no leaks at all.
One point worth repeating is that the gearbox has a designed-in breather via the speedo cable so it's important to not allow the cable to become gunged up by over-greasing, i.e. there needs to be a clear air path between the inner drive cable and the outer cover. If this is blocked, the natural foaming of the oil in the box creates a bit of excess pressure which tends to push the oil out, usually at the scroll seal as this is the 'path of least resistance'. Same principle as the breather on the back axle casing.
David Smith

Apologies for not replying sooner; have been to the delightful and scenic Skipton (despite it being in Yorkshire).

No need for apologies Guy, I'm easily confused at best and I find choosing oils has become much more difficult for our older cars. For moderns just type a reg no in and voila there's a list presented for you.

Thanks for the info from the archives Nigel - like Guy I tend to get diddly squat or indeed a list of hundreds to sort through.

Amazing the things you learn here. I had no idea the speedo cable acted as a breather for the gearbox - better check it's not too tightly routed.

More research needed. Added sulphur EB does not it would appear, offer the protection it claims.

Jeremy MkIII

Jeremy,
"Added sulphur EB does not it would appear, offer the protection it claims" - that not necessarily correct there are claims that it does and claims that it doesn't. I've not seen proof either way that the modern GL5 oils damage or don't, there might be plenty of proof out there but I've not seen it, not that I've looked that far, I find these things tend to be more about belief, faith, practice, habit, etc., rather than real proof.

25+ years ago I was told Mobil 1 would ruin my engine, rot my teeth and steal my good looks yet these didn't happen despite many years and tens of thousands of miles use with Mobil 1 - well perhaps one, my teeth aren't as good as they used to be.

Guy went 40k-miles on GL5 with his T9 and didn't report metal in the drain of oil.

I'll never be able to report on my T9 gets on with the GL5 I've put in it as I can never get enough miles in for replacing the new parts previously fitted and the work done by professionals.
Nigel Atkins

Interesting article, it's for the US but can equally apply here.
This is the link
http://www.widman.biz/uploads/Transaxle_oil.pdf
(apologies if this the same article you're referring to Nigel)
One bit in particular

"Summary
Just remember that GL-4 and GL-5 are gear oil ratings, not transmission oil ratings. Transmissions have gears and synchronizers. These seemingly conflicting requirements must be met differently.
When someone tells you that their GL-5 covers GL-4, remember they are correct as far as EP protection, but that is only half the answer. When they say their Sulfur/Phosphorous additive will not
corrode the yellow metals, they are also correct, but if there are enough to meet GL-5 protection, they will slowly peel away your brass synchronizers."

So Westway is correct in what they say to a point!

The Author's recommendations are also interesting (well to a point!)

"What should you do if you cannot find a GL-4 that does not include GL-5 on its label? My next choice, and one I almost did even though I have plenty of GL-4 80W-90, would be a SAE 50 oil that meets
CAT TO-4 specifications. My third choice would be a SAE 50 diesel motor oil of the highest API classification I could find, preferably group II. As you will see on the graph below, the temperature curve for a SAE 50 motor oil (or CAT transmission oil) and a SAE 80W-90 are very similar."

So it appears this oil is unsuitable for the Midget gearbox (and for the VW transaxle it's currently in. I'll leave it in and drain it after a couple of thousand miles and see if there's any copper residue in it).

The search continues, maybe a straight 30w oil as Willy and Richard have suggested. Or maybe a 5w/30 diesel oil.
Thanks for all the helpful suggestions - as usual.
Jeremy MkIII

Jeremy,
that's the one.

It's certain that he'd know much more about oil than us but the thing that I wonder about is he sells oil and offers an oil analysis service yet he goes from what's on the labels of the products.

If you're going with his recommendations then note -
"In general I would not use a 75W-90 in a Corvair transmission unless it was synthetic, but there are some very good GL-4 Synthetic 75W-90 oils in the market for Mercedes, Volvo and Mack truck and bus transmissions that would be acceptable, especially in colder climates. Look for one where the viscosity at 100ºC is 15 cSt or above. "
Castrol Syntrans Multivehicle 75W-90 Fully Synthetic MTF is GL4 and viscosity, Kinematic at 100°C is 15.09 (mm²/s, method ASTM D445) (no I don't know about the different units of measurement either).

https://www.widman.biz/

https://msdspds.castrol.com/bpglis/FusionPDS.nsf/Files/3A2AC3E19A7AEE6D80257E83003062B0/$File/BPXE-9ZWFHN.pdf
Nigel Atkins

Are these oil recommendations for American cars not biased towards automatics then?
GuyW

Not as such and he recommends a different oil for auto Corvairs.
Nigel Atkins

Thanks again Nigel, Castrol seem to have the market cornered for what we need. I may well be forced to give a try :)
Jeremy MkIII

Jeremy, it's just one option. There are many other makes models and types of oil on offer that could cover your need here.

Not all makes and models of oils are the same even if they in the same type, e.g. 20w50 has a a good few to choose from.

These's also a choice of makes with 30 (and 40 (weight range), I think I'd avoid 50 in your case), here's just one and Millers recommend this for the gearbox -
https://www.millersoils-shop.co.uk/classic-pistoneeze-30-engine-oil
Nigel Atkins

I must say I find this Freedom of Choice thing very difficult to cope with. As a driver, it is all so subjective! With any recognised brand of engine oil you probably wouldn't be sure about a difference for 30,000 miles or more, unless maybe you stripped the engine to inspect the bearings after 15,000 miles. For a road car that is. And with a gearbox you may think it is better or worse but its all very subjective and with all of the other variables like the weather,how heavy the traffic is, what you had for breakfast, what your co-passenger is on about and whether your sciatica is playing up again.
So then you change alliegence (not necessarily with your co -passenger, though that might help). Now, is the change better than it was last summer? Can you really be sure?

So, take advice, pick an oil and that will surely do for the next few years until they ban IC cars completely.

Now wipers, that's a different thing altogether! You can tell immediately if you cannot see!
GuyW

I think you could set yourself up as a consultant here Nigel!

I'm experimenting with Rye Oils 20w/50 engine oil as it has 1500ppm of ZDDP which I'm assured is a very good thing for an oil for our old engines to have. Pity there isn't something similar for my joints.

The simple solution is too stick with what the cars used back in the day but it does seem almost careless not to try and take advantage of the progress in oil technology since the 60s & 70s.

Agree Guy, there's far too much choice. Google anything and you're presented with God knows how many billion results for what you're looking for, with the exception of Midget wiper blades it seems, and can be bewildering.



Jeremy MkIII

I certainly could as I don't know what I'm talking about but I'd fail as I don't charge enough.

I wouldn't fall into the ZDDP numbers trap, apart from the numbers varying back in the day anyway modern additive packages are better and they can include ZDDP that is sufficient, more than sufficient, or possibly not enough if you don't like modern oils or like to see higher numbers.

Guy has a point about choice and as I put earlier to some extent it's all a matter of believe and faith and as with a lot of beliefs only time will tell but it could be too late by then.

Whatever oil you use you will benefit more from doing a thorough change as I detailed in an earlier post.

Personally in your situation I'd put in any suitable oil I had to hand with a thorough change and see if there is any improvement because if there is an upgrade is just another thorough drain/flush/refill. If there's no improvement whatsoever you can decide on your next course of action, stay as you are and double-declutch, get box sorted or thorough drain/flush/refill of better quality oil to try to put off further work for as long as possible.
Nigel Atkins

Another thought which adds to the confusion (sorry) but may also provoke discussion (I hope so).
Gary at Heathrow Transmissions recommends Castrol Classic EP90 for use in all his rebuilt ribcase gearboxes. I will admit I'm not brave enough to take his advice and am sticking to 20/50 or 10/60 Mobil1 synthetic.
David Smith

Interesting this--
I have always believed that GL4 was for transmissions
GL5 was for final drives -transfer boxes etc and was designed with a higher shear pressure rating to leave a film on the parts under pressure to protect against extreme pressure wear--This film reduces the ability of the syncro rings to do their job if GL5 is used in a transmission whereas the GL4 keeps the syncro surfaces clean-

Some modern oils will do both jobs and are designed for transaxles etc

I don't think any of them actually eat the syncro ring metal it's just a case of some are too slippery
IMHO
willy
William Revit

I have to say that a box in good shape is fine with the traditional 20/50 in my experience.(That included Modsport racing in the 80's) Its when they get a bit tired eg layshaft/main bearings wear that troubles seem to arise. Whilst new oils possibly could be an improvement surely it would be necessary to start with two identical boxes one filled with a modern oil and one as the control filled with 20/50 and run them over a period of time to ascertain the performance/wear of each. As probably none of us have the facilities or time to do this, any assumptions we are making over modern oils are a bit subjective.
Bob Beaumont

As I understand it, the ribcase box needs a "thin" oil to provide the correct lubrication. In that case isn't a 30W single grade oil the best i.e. as originally specified? I'm assuming a 20/50 starts off thicker than a 30 and, as the box doesn't get as hot as the engine, stays thicker. Or am I talking nonsense?
Bill Bretherton

Considering engine oil has done the job for sixty years I cant see the point in using transmission oil which is about three times the price.

Trev
T Mason

David,
I could see that a rebuilt gearbox could use EP90 and if that what the builder recommends their must be some merit but I don't think it would help Jeremy with his notchy when hot changes on his gearbox.

BTW when I enquired about using 10w-60 in my engine (rather than gearbox as you have) and wondered if the 60 might be a bit high for street use I was told that within X miles/use it'd be within the 50 range. Sorry to be so vague about details I simply can't remember, I'm not sure if it was Mobil 1 I was asking about either but I think it was.

Nigel Atkins

Trev,
there's no doubt 20w-50 engine oil works but could there be other oils that work better, for longer and cover a wider range of protection margins. The cost is always relative, 3 times isn't that much when spread over 10 years (I'd change much sooner mind) and compared the the cost and hassle of getting the gearbox out of the car and repaired or rebuilt.

It also depends on the use of the car and the owner/driver's expectations of its use and performance whether the possible extra performance and protection margin are wanted or required.
Nigel Atkins

Going to try the Westway and see what happens.
If it improves then hooray, if not nothing lost and may change to a straight 30 :)
Jeremy MkIII

You beat me to it I was going to ask what you were going to/had used - Emu oil, Glucosamine, fish oil etc..

I thought you'd got some spare of the Westaway to experiment with. Whatever you try do the thorough drain and flush of your existing oil (and thorough drain flush of the Westway or whatever if you chose to change from it).

On the drains have good look at the oil that comes out and the initial part of the drain, before you add fresh and/or different oil, keep separate to have a good look at for bits of metal/crude and if possible compare with fresh oil of the same type to see what 10 years and use makes to the oil.

Don't forget to replace the drain plug before refilling. :)

Let us know how you get on.

Nigel Atkins

Bananas Nigel

http://jalopnik.com/how-bananas-saved-a-citroen-2cv-1720454812

Thanks for the advice and will post how it works out.
Jeremy MkIII

This thread was discussed between 13/10/2018 and 21/10/2018

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.