15eren Posted March 31, 2019 Report Share Posted March 31, 2019 (edited) Hi e Sometimes when I make a quick change from 4th to 3th I have a little resistence and a noise as if the synchro is not doing its job. But only sometimes. Normally it is OK. I have checked the clutch and it seems to be functioning perfect. Could it eventually be because when moving the shaft for the 3th and 4th selector, it also engages just a bit either the shaft for the 1th an 2th selector or perhaps the shaft for the reverse selector? I have come to the idea, because the fealing in the gear lever is as if it is trying to engage 2 gears at the same time. I know that there are some bullits to ensure that only one shaft is operating at the same time, but is it a possibility and have others had the same issue? About 6 months ago I had the same problem and removed the top-cover and inspected what could be seen from the top. I found nothing and after putting all together the problem disappeared. But now and then I now have the same problem. That made me think that it could have something to do with the interlock. Regards Tage Edited March 31, 2019 by 15eren Quote Link to post Share on other sites
RogerH Posted March 31, 2019 Report Share Posted March 31, 2019 Hi Tage, There is an interlock in the top cover extension that stops you selecting anything other than what you have started to engage. So it could be your first thought that the 3rd gear syncho is not working as well as expected.. How is the gearbox oil level.? Do you try to match the revs when you change down, perhaps blip the throttle. Roger Quote Link to post Share on other sites
Mike C Posted March 31, 2019 Report Share Posted March 31, 2019 What oil are you using? GL5 oil will stop synchros working due to being too slippery . Quote Link to post Share on other sites
Hamish Posted March 31, 2019 Report Share Posted March 31, 2019 Doesn’t GL5 also “eat” the yellow metals in a gearbox. I have had this recommended for my OD gearbox https://www.moss-europe.co.uk/dynolite-gear-oil-40-1-litre-ggl821210.html Quote Link to post Share on other sites
RogerH Posted March 31, 2019 Report Share Posted March 31, 2019 Hi Hamish, the Dynolite oil does not say what spec it is GL4 or GL5 as far as I can see. Nothing on the packaging that helps. Roger Quote Link to post Share on other sites
Hamish Posted March 31, 2019 Report Share Posted March 31, 2019 (edited) 4 minutes ago, RogerH said: Hi Hamish, the Dynolite oil does not say what spec it is GL4 or GL5 as far as I can see. Nothing on the packaging that helps. Roger Roger All I can say is It’s a Peter Cox recommendation and supply, following a rebuild. H as Mick says below - here is a web extract. Dynolite Gear Oil 40 is a 25w-70 multigrade gear oil that replaces oils originally specified as EP90, SAE40. It is a non-hypoid and non-friction modified high quality multigrade gear oil for use in synchromesh and straight cut gearboxes. Formulated without EP additives making it safe for use with bronze, copper and brass components and without friction modifiers making it safe for overdrive and preselector units. Guaranteed non-recycled base oils. Edited March 31, 2019 by Hamish Added detail. Quote Link to post Share on other sites
Motorsport Mickey Posted March 31, 2019 Report Share Posted March 31, 2019 "the Dynolite oil does not say what spec it is GL4 or GL5 as far as I can see. Nothing on the packaging that helps. " Except perhaps the statement - "It does not contain any EP type additive that would destroy yellow metals such as bronze, copper or brass." I think that might pin it down. Mick Richards Quote Link to post Share on other sites
15eren Posted March 31, 2019 Author Report Share Posted March 31, 2019 Hi all Thanks for your reply so far. I am using Penrite GB-40 gearbox-oil for GB and of course OD. Specification is API GL-1. That should be OK. And Roger: I am aware of the interlock in the top-cover of the Gearbox. Would it be possible that this interlock could fail now and then? Cheers Tage Quote Link to post Share on other sites
RogerH Posted March 31, 2019 Report Share Posted March 31, 2019 Hi Tage, the interlock is quite secure. If it failed it would not be temporary Roger Quote Link to post Share on other sites
astontr6 Posted March 31, 2019 Report Share Posted March 31, 2019 2 hours ago, Hamish said: Roger All I can say is It’s a Peter Cox recommendation and supply, following a rebuild. H as Mick says below - here is a web extract. Dynolite Gear Oil 40 is a 25w-70 multigrade gear oil that replaces oils originally specified as EP90, SAE40. It is a non-hypoid and non-friction modified high quality multigrade gear oil for use in synchromesh and straight cut gearboxes. Formulated without EP additives making it safe for use with bronze, copper and brass components and without friction modifiers making it safe for overdrive and preselector units. Guaranteed non-recycled base oils. Hi All! the word hypoid denotes the gear tooth form and not the oil! This is a common mistake! EP oils have not been attacking bronze parts for over 25 years, as per Castrol and Penrite Technical Depts. But if Dynolite do not give a spec. number or wording I would not use them. It could be anything. My original gear box lasted 44 years on Castrol EP80/90 as per Handbook and that is what has gone back in it, after a full rebuild and modification by ORS. Bruce. Quote Link to post Share on other sites
Litespud Posted March 31, 2019 Report Share Posted March 31, 2019 When rebuilding my A-type O/D ~5 years ago, I contacted John Esposito of Quantum Mechanics at ask some questions, and he recommended 30 wt ND oil for the tranny and O/D. Have used this since with no issues. Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.