Which oils in Gearbox and Engine

[Essex Stag]

I have recently had the rear oil seals done on the gearbox and noticed they put 20/50 oil in the gearbox at which I questioned it ,thought it should be SAE90 . They said no the stag almost has the same overdrive as an MG a Laycock I think and they need 20/50. But in the book it says SAE 90 they have offered to change it if I am not happy, just thought I would check with you lads. Also I have read the post about cheap Halfords Oil, never used it have always used a classic car oil from my garage who only does classics. My question is you recommend Valvoline V1 but there are two advertised one in a plain black can and one in a chequered can but they are both 20/50 V1
Yes I am confused.
Derek

[Lingen]

Derek. Triumph did specify EP90 for the gearbox/overdrive unit, but that was because at that time the "EP" additives only came in the heavier oils. Nowadays, it is also included in any good quality 20/50 oil, or so I was told by Millers Oils when I asked them. When my gearbox came back from a rebuild about five years ago now, I couldn't believe how much better it was, and also the overdrive action was much improved. The bloke who rebuilt it explained that the 20/50 oil he had put in there would make it much lighter to use, particularly in cold weather conditions. The only downside I have found is that you need to wait a bit before engaging reverse, as the damping effect on the rotating parts is less with the thinner oil. Otherwise, from my own experience, I recommend the change to everyone. Mike.

[SGN]

Hi Derek

This is the engine oil - 20/50 Racing mineral oil http://www.eurocarparts.com/ecp/p/ca...0500&0&cc5_251 enter OILDEAL30 at checkout and it's £23.10 / 5 litres. & it's free delivery.

Cheers
Steve

[martin]

Hiya Derek, VR1 is a must for the engine, as Steve says, as for the gearbox, I would suggest that 90 weight is there for a purpose, and of course it has to be EP rated, I would worry about a lighter oil leaking, most of these old girls are incontinent at the best of times.
Mike, interesting about 20/50 having EP qualities, if you're convinced perhaps it's worth trying, of course there is the possibility that some owners will think it applies to all 20/50 oils. Martin.

[Essex Stag]

Thanks Steve and Mike I have just ordered x 5 litre of the VR1 oil thanks for that saved £ 19.80 already half of my SOC membership Cheers for that.
Yes Mike I have noticed I have to change from 3rd to 4th slowly when in overdrive to avoid a slight crunch .
Regards Derek

[DJT]

Derek,

The engine oil is VR1 Mineral Oil. They do a synthetic version as well, which is where the confusion can arise.

The Stag box should be SAE90EP, and that is what I ran mine on for 18 years. Some have changed to 20W50 without problems, I believe.

[mjb67]

I recently emailed Millers tech support to ask which oil to use in the gearbox and they said to use their EP80w90 in the Stag gearbox and axle. However I know that they do a 20w50 which is designed for combined gearbox and engine use. I think it's called Classic Mini 20w50.

[ChasR]

I guess the confusion arises with MGBs which were specified 20W50 oils in the owners manual. In most of the Triumph stuff I have owned (with both Single rail and 3 rail boxes) E80W90 has been just fine.

Here's a question for you chaps. Do the GL4 and GL5 ratings of gear oil make much of a difference to an MOD 'box? I know that using GL5 spec oils in LSD diffs is said to be a big no no in many circles.

MJB, I do not know about Millers selling a gearbox specific oil (remember the 20W50 in a Mini is shared with the engine as well), but Penrite certainly do sell a 20W50 oil specific to gearboxes .

[Firept]

Derek.
I have had a quick look through my info and somewhere I found a site that tested out the "A" type over drive and did not recommend the usual EP90 as it put the pressure in the box too high, perhaps someone else know of the site.
As I have also had cars Mercedes and Volvo that both used TQF in a manual box after some research I have used this http://www.redlineoil.com/product.aspx?pid=46.
It gives much smoother changes there was also somewhere the info I think on buckeye's site that the GL5 did not like the brass components of the gear box so stick to GL4
http://www.buckeyetriumphs.org/techn...GearboxLub.htm.

I've not had any problems been in now for 2 years and probably 6000 miles.

Paul.

[Nambo]

I have always used Mobil 1 SHC 75/90 in my gearbox with O/D, I also use it in all old British bike gearboxes.
It is claimed to be 10 times stronger than Castrol EP 90, it also pours thinner, certainly at room temperature.

Due to the superior qualities of such fully synthetic oils they are generally too slippery in applications where friction surfaces are involved, like in a wet clutch, so I asked Mobil tech back in the day when they had proper men in white coats to answer your questions, they assured me it would be fine to use in the Stag overdrive which indeed it has!

[jleyton]

I use Millers oils in engine, gearbox and diff and have been very satisfied with the results. Apparently the MD of Millers owns a Stag himself and I would have thought that he knows what he is talking about

This is what they said to me, regarding oil for both both O/D gearbox and diff:

Our MD, who is a Stag driver, suggests using the TRX 75w90 in place of the EP90 that was recommended when the car was built. Link to datasheet is here.

http://www.millersoils.co.uk/automotive/tds-automotive.asp?prodsegmentID=118&sector=Car

He says the gear change will be smoother. He uses it in his Stag.

I agree it has made the gearchange smoother but, unexpectedly, it has also made my diff a bit quieter.

For the engine I have been very pleased with Miller's Classic Semi-synthetic 20w/50. It has got the necessary high levels of ZDDP plus the benefits of being semi synthetic.

Cheers

Julian

[Essex Stag]

On my invoice it does state 20/50 gearbox oil so it may not be just any old engine oil I will check as they did say if I was not happy they would willingly change it.

[mjb67]

MJB, I do not know about Millers selling a gearbox specific oil (remember the 20W50 in a Mini is shared with the engine as well), but Penrite certainly do sell a 20W50 oil specific to gearboxes .

Yeah the Miller's product is 'Classic Mini 20W50', it's 20W50 engine oil with EP additives up to GL4 spec, so it's ideal for the shared oil in a mini.

On my invoice it does state 20/50 gearbox oil so it may not be just any old engine oil I will check as they did say if I was not happy they would willingly change it.

I suspect you'll probably be fine if your oil is GL4 spec. Except it may be another cause of Stag Paranoia. But consider this: Triumph specify if you completely refill the gearbox, then fill it with EP75. EP90 is specified for top-ups. I don't really understand oil, but what's closer to the EP75 specified for a refill, 20W50, or EP80w90?

[stag8manod]

Hi Guys, I use Castrol VMX in both the Stag and Spitfire OD gearboxes. Raced the Spitfire for 12 years no problems and it is tricked to work on all four forward. Cheers Ian A.

[Gresley]

I use also use Millers TRX 75w90 in my gearbox with J Type overdrive and the gearchanges have definitely been smoother since, especially when cold. I have Penrite 80/140 (I think it is) in the diff which has run quieter since.

Brian.