EP 90 Gear Oil

[Tnick]

Although I may have sold my Roadster it still seems to be my job to maintain it. So whilst driving it to assess the misfire (new plugs, point stc cured that) I noticed the gearbox seemed noisy. So off to the motor factors to purchase some EP 90 - alas not . They now offer EP 80W90 (I think) which is obviously a multigrade. I asked the assistant if this would be OK for an overdrive Trimph gearbox. The answer I got was possibly - it depends on who you ask. Some say it will be OK and others perhaps not. Fortunately I had sufficient for now. The advice seems to be that some of the EP adativesin newer oils can damage yellow metal parts (ie bronze and copper). The adatives used in the higer rated oils (ie GL5) are potenially more corrosive.

Can anyone shead any light on this? The oil is also used in the front trunions (phosphor bronze!) so any thing that attacks yellow metals would not be a good idea!

Regards

Nick

[CABRIOBOB]

Re: EP 90 Gear Oil

Look at this website as this might help your concern www.opieoils.co.uk.

[stevejgreen]

Re: EP 90 Gear Oil

This has been discussed before here http://www.marlinownersclub.com/foru...ght=drain+plug

At the time my thoughts were:-
It's a debate that seems to be fuelled by internet lore during the past five years or more, and its now very difficult to get back to the truth of the matter.
The information I have suggests that the problem is temperature related and it is unlikely that a domestic use transmission gets hot enough.
I think the failure rate is more likely to be caused by age, many of these diffs would still contain remnants of their original 30 year old oil, I doubt if many diffs have been drained, since they don't have a drain plug, and cleaned thoroughly at any time in their lives, so normal wear and tear is the ultimate cause, rather than any new oil added in the past five years.

Having said that I would suggest using the lubricants originally specified by the manufaturer. But this denies any of the technological improvements that may have happened during the past 30 years.

The bottom line is that for a low mileage vehicle corrosion is the enemy, especially on the trunnions where the suspension upright screws in. If it stands still for six months of the year, almost any lubrication is a bonus. The trunnions should normally be lubricated with a medium pressure Lithium grease.

[cameronfurnival]

Re: EP 90 Gear Oil

Correct me if im wrong but if memory serves me riught Spitfire and Herald trunnions needed gear oil didnt they?

[stevejgreen]

Re: EP 90 Gear Oil

Yes, Spitfire books say use oil in the trunnions. Many of the Triumph forums have debates on the subject with no 'final' answer.
The Marina definately needs grease, at least all my manuals say so though they generally quote Duckhams Q5648

Either way the lubricant should be an EP (Extreme Pressure) grade.

More info may be found at http://www.castrol.com/castrol/subse...tentId=7027417

I think that lubrication technology (tribology) has moved on since 1960 and there are more efficient lubricants around.

[B_Williams]

Re: EP 90 Gear Oil

Always worth having a look at Millers Oils too http://www.millersoils.net/1_Millers_frame_CLASSIC.htm They certainly do an additive free gear oil, I use it in my Husky winch on the Landrover

[neiltechspec]

Re: EP 90 Gear Oil

GL-5 spec gear oil contains more suplhur the GL-4, it may give you less noise but will cause more rapid wear of phosphor bronze shims.

Canley Classics (Triumph Specialist) recommended that I use GL-4 spec oil in my Stag diff as all the Triumph diffs contained phosphor bronze planet wheel shims.

As Marina diffs were actually Triumph internals, then I guess the same will apply.

Neil.

[Tnick]

Re: EP 90 Gear Oil

Thanks for the comments - My research suggests that oil rated GL4 has fewer additives than the GL5 and will be more friendly to older machinery. My initial concerns were for the health of the overdrive as these need a reasonable oilpressure to function, if the oil is too thin )or too hot) they will slip underload .Additioally many years ago I was told about the outcome of adding Molyslip to an overdrive gearbox - not recomended.

As the suspension is Triumph I will continue to lubricate the trunions with gear oil (as rquired by the manufacturer) this is what I've used on this type of car over the past *0 years or so! As the trunions don't get very warm any corrosive effect will be reduced.


Regards

Nick

[CosworthCabrioLee]

Re: EP 90 Gear Oil

I would agree never ever put grease in trunnions, ok when new but after a while it turns solid and acts as a cutting paste. Always use gear oil 2 or 3 times a year

[andy4]

Re: EP 90 Gear Oil

A good source for unusual oil is Castrol Classic oils - you can get most stuff post free if you need over £30 worth of stuff and have always found them efficient at sending - use them for Castrol ATF auto fluid in my other car - suprising that things you could pick up in any motor shop a few years ago are just not easy to get anymore ....

http://www.castrol.com/liveassets/bp_internet/castrol/castrol_uk/STAGING/local_assets/downloads/c/Castrol_Classic_Retail_PL_November_2011.pdf