Bazza Posted August 4, 2016 Report Share Posted August 4, 2016 I'm looking to change the gearbox oil and the manual recommends 90/140. But this seems to be impossible to get. Suggestions for an alternative? Thanks. Quote Link to post Share on other sites
Andrew Smith Posted August 4, 2016 Report Share Posted August 4, 2016 I've used Penrite 40 in my TRs for years. Cheers Andrew Quote Link to post Share on other sites
RogerH Posted August 4, 2016 Report Share Posted August 4, 2016 +1 Penrite GB40 etc very good Roger Quote Link to post Share on other sites
iain Posted August 4, 2016 Report Share Posted August 4, 2016 Also available from the TRRshop I believe for a good price Quote Link to post Share on other sites
Bazza Posted August 4, 2016 Author Report Share Posted August 4, 2016 Thanks for the replies so far. I can get 85/140 would this work Quote Link to post Share on other sites
Kevo_6 Posted August 4, 2016 Report Share Posted August 4, 2016 Penrite GB40, good stuff, get it from the Register shop delivery is really quick, well it was for me. Quote Link to post Share on other sites
Bazza Posted August 4, 2016 Author Report Share Posted August 4, 2016 Thanks chaps, I'll go for the Penrite Quote Link to post Share on other sites
RogerH Posted August 4, 2016 Report Share Posted August 4, 2016 Hi Bazza, you can put most slippery things in the gearbox with no problems. Try and steer clear of EP oils as these may cause issues in the OverDrive if fitted. Thicker oils may cause the OD to be sluggish (especially when cold) but they may also reduce oil leaks. The thinner oils 30/40/50 run very well and the OD is happy. But may make any leaks look worse than they are. Use a gearbox oil rather than an engine oil. Roger Quote Link to post Share on other sites
Guest ntc Posted August 4, 2016 Report Share Posted August 4, 2016 Used engine oil 20/50 for 30 years never had a problem as recommend by Roy Talbot and others Quote Link to post Share on other sites
Andy Moltu Posted August 4, 2016 Report Share Posted August 4, 2016 If you use 20/50 engine oil it needs changing frequently as the viscosity additives can be sheared by the gears so won't last like 80/90 gear oil which is similar in terms of viscosity. Quote Link to post Share on other sites
rhine Posted August 4, 2016 Report Share Posted August 4, 2016 Think that you need GL4 spec oil - something to do with additives and 'yellow metal' gearbox components. Am sure can describe this in a more technical way. I found GL4 80/90 oil from our friends at Halfords. Let's see what happens. Looks like this topic has been discussed before - have a look @ http://www.tr-register.co.uk/forums/index.php?/topic/36170-gearboxod-oil-is-gl5-8090-ok-as-opposed-to-gl4-ep8090/?p=272095 Richard Quote Link to post Share on other sites
astontr6 Posted August 5, 2016 Report Share Posted August 5, 2016 I have to agree with Andy! Have used 80/90 GL4 for 43 years as per BL TR6 Hand Book and had no problems. The only engine oil that is suitable for gear boxes is Mini Engine Oil as it has gear oil additives but I would be uncertain if it was up to the mark regarding O/Ds due to the very high pressure required to operate this unit. Lastly, I am also uncertain as to the life of the lay gear bearings, which is the weak point in a TR Gear box would be shorten by the use of non hypoid oils, as an extreme pressure oil, is required! Bruce. Quote Link to post Share on other sites
RogerH Posted August 5, 2016 Report Share Posted August 5, 2016 Hi Bruce, your concern over the bearing and EP oil may explain why ST went over to EP on the TR4A/5/6. Laycock overdrives were specified with SAE40 etc with a serious warning NOT to use EP oil as it would stop the OD working. I suspect from the 50's to the 60's and into the 70's oil improved a little and ST took the gamble to save the GB at the expense of the OD (which one would fail first) Likewise with 20/50 engine oil. These had fair quantities of detergent to help keep the engine oil ways clean. Modern variants of the same stuff appear to have less. Too much detergent could cause frothing and cause problems with the OD pump. I would still stick with a quality gearbox oil personally. Roger Quote Link to post Share on other sites
astontr6 Posted August 5, 2016 Report Share Posted August 5, 2016 Roger, I have see what engine oil did to an A type Overdrive it gummed up the works with white froth! EP 80/90 oil is on a different SAE viscosity scale to Gear Oil SAE 40. If one uses the Gear Oil SAE Scale for Hypoid you will find that that EP 80/90 is roughly the same as 40 Gear Oil! I have never seen any paperwork from GKN that advises what oil to use as I know that at least 3 types of overdrives were produced-- D, A, & J. So the use of 40 Gear Oil, does this apply to a 'J' type O/D? Lastly Volvo did not use 40 Gear Oil but used TQ and their units often have done 250K miles before re-furb. Bruce.. Quote Link to post Share on other sites
RogerH Posted August 5, 2016 Report Share Posted August 5, 2016 Hi Bruce, The different OD'd mat well have a bearing( ) on the oil used. The 'A' type was definitely spec'd with SAE40 until later in the 60's Roger Quote Link to post Share on other sites
Bazza Posted August 5, 2016 Author Report Share Posted August 5, 2016 Many thanks for all this. Looks like a few options. Cheers Quote Link to post Share on other sites
astontr6 Posted August 5, 2016 Report Share Posted August 5, 2016 Roger, Are certain that by the 1970's that GKN who now owned Laycock had not brought the ' A' Type O/D up to date, for that time, by having to use, better seals, 'O' Rings and gasket materials, etc.? As TQ, as used by Volvo and others was a very aggressive oil, for it's time, it destroyed nitrile seals, in a very short time, as they went hard.? It makes Hypoid look a mild non aggressive oil? Bruce. Quote Link to post Share on other sites
Guest ntc Posted August 5, 2016 Report Share Posted August 5, 2016 http://www.mgexp.com/article/mgoc-basic-2.html Quote Link to post Share on other sites
Peter Cobbold Posted August 5, 2016 Report Share Posted August 5, 2016 I've used EP80-90 ( no idea of GL spec) for 280k miles. Had a layshaft bearing go at around 150k miles. No o/d issues, apart from slight delay. Peter Quote Link to post Share on other sites
Nigel Triumph Posted August 5, 2016 Report Share Posted August 5, 2016 I've always used EP90 GL4, as specified by Triumph for gearbox, overdrive and differential. Two points worth mentioning: 1. The oil must be GL4, as the additives in GL5 can attack bronze/brass bushes and synchro rings. 2. I've never had a problem with the A-type overdrive on my TR6 when using EP90. That's over 10 years and thousands of miles. The D-type O/D on my GT6 has been slow to engage and this has been improved by using a slightly thinner EP75/80 GL4 oil. Nigel Quote Link to post Share on other sites
Andy Moltu Posted August 5, 2016 Report Share Posted August 5, 2016 In theory GL4 80w90 is the lube of choice - as has already been said GL5 can have adverse effects on the yellow metal bits and shorten their lifespan. Not too sure the EP90 is too much of a problem with the overdrives , however it can make for a very stiff gear change on a cold morning. I think 80w90 is of a similar viscosity to 20/50 engine oil. Quote Link to post Share on other sites
Andy Moltu Posted August 9, 2016 Report Share Posted August 9, 2016 I have to agree with Andy! Have used 80/90 GL4 for 43 years as per BL TR6 Hand Book and had no problems. The only engine oil that is suitable for gear boxes is Mini Engine Oil as it has gear oil additives but I would be uncertain if it was up to the mark regarding O/Ds due to the very high pressure required to operate this unit. Lastly, I am also uncertain as to the life of the lay gear bearings, which is the weak point in a TR Gear box would be shorten by the use of non hypoid oils, as an extreme pressure oil, is required! Bruce. Back in the day there wasn't a Mini oil option and the ran regular 20/50. Quote Link to post Share on other sites
peejay4A Posted August 9, 2016 Report Share Posted August 9, 2016 +1. My 1275GT ran on GTX. Quote Link to post Share on other sites
mike3739 Posted August 9, 2016 Report Share Posted August 9, 2016 +2 1340cc Mini Cooper S GTX Quote Link to post Share on other sites
Andy Moltu Posted August 10, 2016 Report Share Posted August 10, 2016 My Mini 1000 had to make do with B&Q 20/50! Quote Link to post Share on other sites
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