johny Posted June 28, 2020 Report Share Posted June 28, 2020 Thing is aren't some synchros steel so won't have the potential for damage by the oil like bronze ones? Link to comment Share on other sites More sharing options...
Clive Posted June 28, 2020 Report Share Posted June 28, 2020 2 hours ago, alan.gilbert_6384 said: Ah, what's the difference with this one Ive been using apart from the E at the end, the data sheet says it should be fine but I would appreciate some advice, thanks. If not clearly stated as suitable for manual transmissions, do not use. The synchros will not grip enough, and will lead to crunchy changes. Nothing to do with yellow metals... (the yellow metal is more of an issue in diffs where heat comes into play, but most GL5 oil is yellow metal safe if you check with the manufacturer.) Link to comment Share on other sites More sharing options...
Pete Lewis Posted June 28, 2020 Report Share Posted June 28, 2020 if its unsuitable for autos i guess its unsuitable for overdrives if its the brake band slip at risk seems more for final drives than gearboxes as for gears under extreme load !! but im a use a triumph spec dinosaur pete Link to comment Share on other sites More sharing options...
alan.gilbert_6384 Posted July 7, 2020 Report Share Posted July 7, 2020 Hi All, Thanks very much for all the suggestions. I really value your empirical knowledge. Still trying to get the bottom of the GL4 or GL5 for the gear box. Here's what I've got so far. 1. Triumph spitfire 1500 hand book, GL5 (overseas, ?) 2. Haynes manual; Hypoid gear oil, viscosity SAE 90 EP. 3. Spitfire 1500 work shop manual; Hypoid 90, with GL4 for overseas, this is opposite to the hand book above?(maybe brexit was a thing then as well ;). 4. Herald 1200 12/50 vitesse 6 chart; Hypoy gear oil (what's the heck is hypoy). Aghhhhhhhh P.S. I'm doing this because the weather is rubbish and I can't go outside. Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 7, 2020 Report Share Posted July 7, 2020 accepting some modern GL5 is yellow metal friendly my experience of having oil specs changed without forthought caused diff thrusts to degrade within warranty and whilst truck diffs have a hard life all down to purchasing going for a GL5 when GL4 was the spec and not realised till crates of diffs started to arrive Hypoy is just a name suitable for hypoid gear sets , which has additives to suit the hypoid diff longer tooth profile than a bevel gear pretty much all shown as EP extreme pressure oils 1 Link to comment Share on other sites More sharing options...
Clive Posted July 7, 2020 Report Share Posted July 7, 2020 You have my bit from above. Not sure why Triumph erronously state GL5 in a handbook, when even current cars are clear GL5 is unsuitable for manual transmission. I read somewhere many engine oils would meet GL4 spec, pretty sure it was on a spiel that was posted a while ago on oils. If you wish to try GL5 oil, go ahead. It may be fine. But do report back after a few hundred miles and let us know if the synchros are working OK. Link to comment Share on other sites More sharing options...
thescrapman Posted July 8, 2020 Report Share Posted July 8, 2020 Engine oil can be used successfully in overdrives and gearboxes, I am pretty sure that is what MGB use. not in the diff though Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 8, 2020 Report Share Posted July 8, 2020 many makes with better gearboxes used engine oil in gearboxes (and OD) but the small chassis triumph boxes has some very weak points like the dreaded mainshaft tip spigot and layshaft needles which is why ep90 is specitfied ,(also was agreed by laycock) yes there are modern oils that may be better these days but if you want any life from these weedy gearboxes i reckon stick with EP Pete Link to comment Share on other sites More sharing options...
Clive Posted July 8, 2020 Report Share Posted July 8, 2020 2 hours ago, thescrapman said: Engine oil can be used successfully in overdrives and gearboxes, I am pretty sure that is what MGB use. not in the diff though Apparently most engine oils meet GL3 or 4 spec! Lots of TR owners seem to like it, and laycock spec'd it for overdrives. But as always, manufacturer instructions trump all else, and Triumph spec'd a number of gear oils. I have been thinking about oils, not too much as lots of stuff happening in my poor brain at present. But I wonder how many people baulked at the idea of using 20/50 oil in the 60's, and insisted it was the spawn of satan, instead using straight 30 oil. (I know somebody who has used straight 30 oil in their mk3 spit for over 100K now). I guess that argument is why so many are concerned about anything with the work "synthetic" on the tin, when in fact oils have been using synthetic additives for decades. I REALLY like commas SX 75-90 GL4 gear oil. Doesn't smell ghastly even after a few years use. May start using it in my Triumph box, when I run out of my current stock of gear oil. Link to comment Share on other sites More sharing options...
NonMember Posted July 8, 2020 Report Share Posted July 8, 2020 3 hours ago, Pete Lewis said: many makes with better gearboxes used engine oil in gearboxes Including Triumph! At least, the constantly changing oil specification for late TR7s (with the Rover gearbox) went through a brief period of being engine oil. Link to comment Share on other sites More sharing options...
alan.gilbert_6384 Posted July 17, 2020 Report Share Posted July 17, 2020 On 08/07/2020 at 10:53, clive said: Apparently most engine oils meet GL3 or 4 spec! Lots of TR owners seem to like it, and laycock spec'd it for overdrives. But as always, manufacturer instructions trump all else, and Triumph spec'd a number of gear oils. I have been thinking about oils, not too much as lots of stuff happening in my poor brain at present. But I wonder how many people baulked at the idea of using 20/50 oil in the 60's, and insisted it was the spawn of satan, instead using straight 30 oil. (I know somebody who has used straight 30 oil in their mk3 spit for over 100K now). I guess that argument is why so many are concerned about anything with the work "synthetic" on the tin, when in fact oils have been using synthetic additives for decades. I REALLY like commas SX 75-90 GL4 gear oil. Doesn't smell ghastly even after a few years use. May start using it in my Triumph box, when I run out of my current stock of gear oil. Hi All, Found this really interesting article on the oils, goes someway to exapliaing why oil companies say GL5 is safe for yellow metals, but it also explains why its no good for synchros, worth a read. https://www.widman.biz/uploads/Transaxle_oil.pdf @ Clive like your suggestion of Commas SX 75-90 GL4 gear oil, just found this on fleabay and its on its way https://www.widman.biz/uploads/Transaxle_oil.pdf Link to comment Share on other sites More sharing options...
GT6M Posted July 17, 2020 Report Share Posted July 17, 2020 for,t last 10-12 years or so, been running a fully synth 80-140 oil in gb, od, diff, ne downsides at all, no stiff changes, slow sycro action, boxes been apart often,{ broken teeth / snapped shaft / bent shaft. } syncros fine, thrusts fine, od comes in muchess faster, even in 1st nee yella stuff on oil changes, 3 times a year some times, 2 mostly depends on hoo long been at W1+ for long periods, { 250+ degs is an oil killer, hence changes } And, it meks things a wee bit quieter too. Befoer I used this stuff, I bunged in some ATF in GB OD t,give it a clean oot, gear change was v v notchy, an GB was v v noisy drained it oot after aboot 300 miles, an bunged in the 140 stuff, niva looked back since As for the Commas SX 75-90 GL4 gear oil, total sheite, honestly, it goes black an pours like thin pish after a 500 mile thrash 200 miles at W1+ feels like pish too, nee lube quality left, like most of the others did which I tried. but, if yer a potterer, no building heat up, then it,ll be ok M Link to comment Share on other sites More sharing options...
Nigel Clark Posted July 19, 2020 Report Share Posted July 19, 2020 Hi Marcus, Which 80-140 synthetic gear oil do you use please? There aren't any I can find that are GL4 or claimed to be safe with yellow metal. Nigel Link to comment Share on other sites More sharing options...
GT6M Posted July 19, 2020 Report Share Posted July 19, 2020 Penrite Pro Gear oil 80/140, not the ordinary stuff as its diff, so P Tech said. git it of Dave Parker at classic group, think its 15-20 £ for 2.5 litres, muchess cheaper if got at the shows. an muchess cheaper than owt on Flea Bay 07391 590149 https://penriteoil.com.au/products/pro-gear-80w-140-full-syn ev a read thru all the blurb M Link to comment Share on other sites More sharing options...
Nigel Clark Posted July 19, 2020 Report Share Posted July 19, 2020 Thank you, Marcus. I've had a read and Penrite say their extreme pressure additive is 'generally safe for yellow and white metals'. That's good enough for me and I will give it a go in the GT6. I've already put a mineral EP80W140 in the Salisbury axle on my Scimitar GTE, replacing the specified EP90. The diff is a lot quieter, with less chatter than before and so far no adverse effects. One of the guys on the Scimitar forum has been using it in the axle of his SE5A racer for years and recommends the thicker oil. I'm already thinking about putting this Penrite synthetic in the Scimitar - it must be better than the mineral oil even if it is nearly twice the price! Nigel Link to comment Share on other sites More sharing options...
SpitFire6 Posted July 19, 2020 Report Share Posted July 19, 2020 If cost is not a problem & its for a diff. RedLine makes some good gear oils. Their VI is generally 150+. A 75W/140 could be superior to a 80W/140. Don't use engine oil, AFF or mineral oils. LOL. Link to comment Share on other sites More sharing options...
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