Two new racecars in NZ
- Thread starter Frans
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Can you elaborate a bit on the causality of the issues? What, for instance, is the contra-indication story for synchromesh?
The problem is that there are additives in the oil and sometimes tiny particles which are there to cushion the shock on the Dogs as they Bang into engagement. The gears are all constant mesh and assuming there is no excessive clearance or wear issues, there is little shock load on the actual gear teeth. Some of the oils are black as they contain Graphite which coats onto the running surfaces or other additives which do the same thing. A synchro box works on friction , so you are just putting yourself at a disadvantage using the wrong product.
The marketing people are kinda misleading too in their adverts. Most competition cars use dog boxes, so they market that way, We are competing with road boxes, so need to use the correct oils. If we didn't have the Final drive in the box we could use ATF for the gears only. You get great shifting with it, but your CWP will only last 500 miles as it cant cope with the Hypoid shearing forces. There was an Audi model which Did this and the input shaft passed through the Diff area with EP into the box with ATF, the seals failed and the boxes swapped spit as it were and the CWP failed.
A transaxle has a Disadvantage that the gears and final drive want 2 different lubricants, The good news today is there are some excellent products around which give the best of both worlds effect.
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Thanks for that. In continuation, I take it that, as the synchro rings rely on friction, the concern is mainly that their capacity to seize things enough to manage to synchronise different rotating speeds is compromised.
I double-declutch almost everywhere standardly so am not fussed by synchro operation & am attracted by its prospects of reducing CWP wear whilst lessening friction losses.
Any comments on these matters?
I double-declutch almost everywhere standardly so am not fussed by synchro operation & am attracted by its prospects of reducing CWP wear whilst lessening friction losses.
Any comments on these matters?
Basically it is best practice to ignore marketing people and put the correct oil for your gearbox in your car. It will provide the best protection and give the best change.
Multigrade gear oils were not available until recently if they had been around in the Fifties, Car makers would have used them.
The gearbox likes a light oil the CWP likes something heavier, so a multigrade ticks both boxes.
I don't suppose you double declutch on the way up, but the synchros work quite hard on the way up, it is easy to forget this. Frans comments about his recent experience on this are a valuable insight here.
Multigrade gear oils were not available until recently if they had been around in the Fifties, Car makers would have used them.
The gearbox likes a light oil the CWP likes something heavier, so a multigrade ticks both boxes.
I don't suppose you double declutch on the way up, but the synchros work quite hard on the way up, it is easy to forget this. Frans comments about his recent experience on this are a valuable insight here.
I admit upfront the oil is not meant for synchro gearboxes.
I knew some racers many years ago that were using it in their synchro boxes successfully, with a most amazing drop in the race temperature in these boxes. I tried it around 20 years ago, with similar results regarding temperature, and have it in 4 synchro and 1 dogbox, and a diff in my own vehicles, 3 of these being Renault transaxles. I have had no problems, and it even improved the synchros so much in a friends Alpine GTA Turbo box that he was about to rebuild, that it never did get done. That was about 14 years ago. As you have said, Redline recommend other products in their lineup for our Renault transaxles.
In the past I have seen many cases of 80W90 oil being used in Fuegos, which seemed to destroy synchros, but the boxes lasted well with Castrol VMX80, so I don't think it was a general failing in the build materials of the box. There must be more than a slight increase in viscosity causing this. Perhaps it was a GL5 oil that at the time at least, did not get along with yellow metals, being the brass type synchros used.
Renault have not used Soft Baulk rings probably since the 50's. The NG series boxes have weaker synchros in general, which is strange as they are basically the same design as the 300 series boxes, but not identical (the rings are not interchangeable). There was a change in the oil recommended to a 75/90 late on. The issue is the springs that hold the baulk rings Cocked in position don't, and allow enough float to give rough changes esp. when cold and the issue develops until it happens all the time.
As you have found out, the oil can make a startling difference to how a gearbox performs. I would never put straight 90 in a Renault transaxle as it is too thick, they were specced for 80 and that is marginal when you live in a cold place, it is amazing how lowering to 75 makes such a difference, when you can also have the benefit of 140 protection when it is stinking hot
As you have found out, the oil can make a startling difference to how a gearbox performs. I would never put straight 90 in a Renault transaxle as it is too thick, they were specced for 80 and that is marginal when you live in a cold place, it is amazing how lowering to 75 makes such a difference, when you can also have the benefit of 140 protection when it is stinking hot
Penrite recommend the following oils:
300 series transaxles: Pror Gear 75W-85 https://penriteoil.com.au/products/pro-gear-75w-85-full-syn
NG series transaxles: Trans Gear 75W-90 https://penriteoil.com.au/products/trans-gear-75w-90-semi-syn
Castrol recommend the following oils:
300 series transaxles: Castrol Manual VMX80
NG series transaxles: there is no recommendation
Its interesting what the above oil companies recommend and what Steve is saying about the differences in synchros between Renault's 300 series and NG series transaxles.
300 series transaxles: Pror Gear 75W-85 https://penriteoil.com.au/products/pro-gear-75w-85-full-syn
NG series transaxles: Trans Gear 75W-90 https://penriteoil.com.au/products/trans-gear-75w-90-semi-syn
Castrol recommend the following oils:
300 series transaxles: Castrol Manual VMX80
NG series transaxles: there is no recommendation
Its interesting what the above oil companies recommend and what Steve is saying about the differences in synchros between Renault's 300 series and NG series transaxles.
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A few things:
I double declutch up except for 3-4.
I drove the 4CVG yesterday & deliberately did not DDC anywhere & did some harsher than my habitual practice downshifts. Synchro was fine.
A Penrite multigrade was my choice until it changed formulation & ate the synchros ("gold" dust in the oil when changed). I gather that GL5 is a "no-no".
FMX 80 seemed not to be sufficiently EP for the CWP. Both the Djet & the 4CVG developed sudden-onset diff noise during 200 km highish speed runs with FMX 80 soon after insertion {first such run}. Perhaps a coincidence but I lost confidence & inserted Redline in an attempt to stabilise matters. That something is the oil intended for the transaxle doesn't imply that something not intended for it might not be better (multigrades instead of EP80 is a case in point & Redline might be another). In short, one has to be wary in wielding 'correct' I submit.
cheers! Peter
I double declutch up except for 3-4.
I drove the 4CVG yesterday & deliberately did not DDC anywhere & did some harsher than my habitual practice downshifts. Synchro was fine.
A Penrite multigrade was my choice until it changed formulation & ate the synchros ("gold" dust in the oil when changed). I gather that GL5 is a "no-no".
FMX 80 seemed not to be sufficiently EP for the CWP. Both the Djet & the 4CVG developed sudden-onset diff noise during 200 km highish speed runs with FMX 80 soon after insertion {first such run}. Perhaps a coincidence but I lost confidence & inserted Redline in an attempt to stabilise matters. That something is the oil intended for the transaxle doesn't imply that something not intended for it might not be better (multigrades instead of EP80 is a case in point & Redline might be another). In short, one has to be wary in wielding 'correct' I submit.
cheers! Peter
There is something in what you say. As Renault specified EP80 for the 300 series transaxles in period (oddly the 5 speeds were specced for a GL5 oil, but the rings are the same part nos, 4 and 5 speed???) this is the info you find for ever after. When an oil manufacturer produces a new product, they are not interested in 50 year old cars for selling it, that is not the bulk market for the new product, which may be very suitable for our old cars. The parts of the baulk ring that contact the cone, the serrated pads or rings should feel sharp as should the pad edges, the hub teeth should be clean and free from peening (some chance) They do wear and will produce a hint of bronze in the oil, but only a hint.
Some noises can be quietened by oil. Hot noise by a thicker oil and cold noise by a thinner one. You don't have to be the sharpest knife in the drawer to realise that fixing one problem may cause another. Indeed my own cold shift, and wanting a rocket fast shift on a box which was a bit tuneful owing to multiple parentage of the parts, looked like an issue that would only be resolved, by using a thin oil which would make it more tuneful, with better shifting. Going to Millers 75/110 cured everything which amazed me, but keeping it inside the box is an issue, it's that thin, but it killed the noise more than 50 percent.
Lastly Always change your gearbox oil every 2 years maximum, irrespective of how many miles it has done. Having had more than 150 Renault Transaxles in bits over the years, virtually every fault I have found traces it's way back to insufficient oil or contaminated oil or both. This is a lesson to us all.............
Some noises can be quietened by oil. Hot noise by a thicker oil and cold noise by a thinner one. You don't have to be the sharpest knife in the drawer to realise that fixing one problem may cause another. Indeed my own cold shift, and wanting a rocket fast shift on a box which was a bit tuneful owing to multiple parentage of the parts, looked like an issue that would only be resolved, by using a thin oil which would make it more tuneful, with better shifting. Going to Millers 75/110 cured everything which amazed me, but keeping it inside the box is an issue, it's that thin, but it killed the noise more than 50 percent.
Lastly Always change your gearbox oil every 2 years maximum, irrespective of how many miles it has done. Having had more than 150 Renault Transaxles in bits over the years, virtually every fault I have found traces it's way back to insufficient oil or contaminated oil or both. This is a lesson to us all.............
Well I've taken out the Lucas 80W-140 Heavy Duty Gear Oil (ie treacle) and now filled with the Lucas Synthetic 75W-140 gear oil. Immediately you could see (by poring it out) that it was much thinner and a far cry from the "treacle".
I took the R8 out for a drive on Sunday (to MotorClassica in Melb CBD - 10kms) and eased the gears in whilst allowing for the oils and motor/gbox to get up normal operating temp.
Although all shifting of gears was easier, the 3-4 gear up change still had some grating (admittedly reduced).
I'm with Aln that although not meant for syncro gearboxes, the Redline shockproof in my opinion has performed much better with smoother changes in all gears and no grinding at all, especially in the 3-4 up change - with the only caveat on the shockproof that it must be properly warmed up before using it in anger.
Considering the low kms I do (albeit working slightly harder not being an every day at all but doing the occasional track/regularity/sprint event), I am seriously thinking about going back to the shockproof - if you can get 14 years of trouble free changing, then the syncros will will probably outlast me.
I don't fully understand the science behind it, but if it works, I believe leave it alone.
My thoughts and (limited) experience only
I followed Alan's experience with the Redline shockproof and have had it in my 314 gearbox (4CV) and 330 gearbox (R8) for some years now. (Mr Dauphproto, re 2-year changes, I'm guilty!) I've had no issues and good changes. I think with modest km/a (1,000 - 5,000 averages) and a mild climate without seriously cold temperatures (condensation) I can run more than 2 years between changes but I'm not arguing for one moment for UK conditions. I'll change the R8 now though as it has done more like 20,000 km I think and it must be more like 5-7 years since I replaced the selector rod seal!!!Well I've taken out the Lucas 80W-140 Heavy Duty Gear Oil (ie treacle) and now filled with the Lucas Synthetic 75W-140 gear oil. Immediately you could see (by poring it out) that it was much thinner and a far cry from the "treacle".
I took the R8 out for a drive on Sunday (to MotorClassica in Melb CBD - 10kms) and eased the gears in whilst allowing for the oils and motor/gbox to get up normal operating temp.
Although all shifting of gears was easier, the 3-4 gear up change still had some grating (admittedly reduced).
I'm with Aln that although not meant for syncro gearboxes, the Redline shockproof in my opinion has performed much better with smoother changes in all gears and no grinding at all, especially in the 3-4 up change - with the only caveat on the shockproof that it must be properly warmed up before using it in anger.
Considering the low kms I do (albeit working slightly harder not being an every day at all but doing the occasional track/regularity/sprint event), I am seriously thinking about going back to the shockproof - if you can get 14 years of trouble free changing, then the syncros will will probably outlast me.
I don't fully understand the science behind it, but if it works, I believe leave it alone.
My thoughts and (limited) experience only
Regarding double-declutching with synchromesh, I'm not so sure. If you haven't got the revs just right, the synchro will be working hard during a quick ddc change. I know with the R8, if I do ddc I can feel whether I've got the revs right or not as it slides into gear. Mostly I can feel synchro baulking, showing I do not have the revs right and the synchromesh is needingt to work. Fine teeth to synchronise.....
Great discussion for which thank you all.
I'm not up with the lubrication theory and practice, just to start......
My 4CV, in 1967, used Castrol "Hypo 90" if I recall, or a name very similar. The synchro was never fast, as it was a prewar design with no baulk ring. But it worked most of the time. The later transaxles, like my 314, have "proper" synchromesh.
However, standard Citroen CX 4-speed manual transmissions ran one of the normal gearbox oils (can't remember which) and were noted by Citroen folk for synchro failures, specifically wear on the steel cone face not the brass/bronze synchro ring. Who knows how often these failed gearboxes had oil changes? The fascinating C-matic transaxles were a modified 4-speed box with three synchronised forward speeds and synchro on reverse. Same basic gearbox and they used auto trans fluid (Dexron 2 maybe) and never had synchro problems AFAIK. Having owned one for 12 years, I can verify the C-matic synchro was perfect every year on Dexron 2.
Fascinating business and a hint of black magic. No doubt the real transmission specialists can explain.
I would give the new oil you have used a bit longer to prove itself, maybe a few hundred Klms. I know in the past with 2 Fuegos, that changing the oil from 80W90 to the 80W the synchros would improve over a month or so of regular use. I have no explanation of this as I would have thought any of the old oil film left on the synchro or cone would be gone in minutes of use.
I think it would be worth an e-mail to Redline's customer service to ask about Suitability, There may be a Synchro version of the oil available which would give you all the benefits and none of the drawbacks.
I remember helping a mate strip a Tremec 5 speed and wondering why the inside of the box had been painted Yellow, then realising that this was the Sulphur that had spun out of the oil and had coated the entire insides of the box. This was an Ex TVR Tuscan Racer which had been retrofitted with a big Ford V8. This had been using old fashioned High Sulphur Race Gear Oil.
I have noticed that most of the new multigrade oils do not have the classic smell, it is still there, but much less than the EP of my youth.
Another thing worth remembering is that we are all trying our best to get the maximum service life out of our vehicles (Me included)
My Mate when he was challenging for the Scottish Tarmac Championship (and winning) was replacing the Dog rings in His Hewland box 2-3 times in the season, Which reduced to annually with the advent of Powered sequential shift (with an ECU on the box to control the shift including a servo motor for blipping the throttle on the Downshift) meaning the machine was better at changing gear than a Human
Some of the guys in the Scottish Classics championship are Changing Ford Baulk Rings after 2-3 races, the quality of the re-manufactured parts is that poor.............................
I remember helping a mate strip a Tremec 5 speed and wondering why the inside of the box had been painted Yellow, then realising that this was the Sulphur that had spun out of the oil and had coated the entire insides of the box. This was an Ex TVR Tuscan Racer which had been retrofitted with a big Ford V8. This had been using old fashioned High Sulphur Race Gear Oil.
I have noticed that most of the new multigrade oils do not have the classic smell, it is still there, but much less than the EP of my youth.
Another thing worth remembering is that we are all trying our best to get the maximum service life out of our vehicles (Me included)
My Mate when he was challenging for the Scottish Tarmac Championship (and winning) was replacing the Dog rings in His Hewland box 2-3 times in the season, Which reduced to annually with the advent of Powered sequential shift (with an ECU on the box to control the shift including a servo motor for blipping the throttle on the Downshift) meaning the machine was better at changing gear than a Human
Some of the guys in the Scottish Classics championship are Changing Ford Baulk Rings after 2-3 races, the quality of the re-manufactured parts is that poor.............................
Thanks for that. The Redline oil certainly doesn't smell like Castrol Hypoy 90 I agree!
And another example of poor quality repro. parts eh? I see one of the French suppliers is offering new synchro springs for 330 etc gearboxes - wonder whether they are NOS or newly made? There are some very bad reports about repro R16 front suspension bushes in Australia although the supplier denies anyone else has reported problems.
I guess that inside the synchro hub it takes quite a while for the oil to exchange. Not that I'd have predicted this but it does make sense. Maybe it needs practically all of something that is in the 80W90 to be removed? Interesting. I'm very happy with the Redline oil and am pretty sensitive to how the gearbox feels - I guess that if there were a problem, some 20,000 km would have shown it up!
What a classic useful Aussie Frogs discussion. It is true that a simple thing like gearbox oils has been a problem for Renaults ! Now they are older, people want to preserve them and would put in whatever works well. But the mystery is what that is. As said the current suppliers are not really interested in some small number of old cars, no sales profit there.
I have contacted some suppliers occasionally and got generic answers that were not very helpful. In Australia I believe all the information has been supplied by one source that they all subcribe to. {same applies to parts listings}
Hmm are there no contacts in the oil business to get the inside goss !! A friend had an uncle there but he passed on some years back.
Jaahn
It is true that a simple thing like gearbox oils has been a problem for Renaults ! Now they are older, people want to preserve them and would put in whatever works well. But the mystery is what that is. As said the current suppliers are not really interested in some small number of old cars, no sales profit there.I have contacted some suppliers occasionally and got generic answers that were not very helpful. In Australia I believe all the information has been supplied by one source that they all subcribe to. {same applies to parts listings}
Hmm are there no contacts in the oil business to get the inside goss !! A friend had an uncle there but he passed on some years back.
Jaahn
Yes I intend to see how I go as I have a regularity event at Sandown on the 23 Oct and see if it improves after a bit of use there afterwards.
I'll keep everyone updated on my gear oil journey.....
I'll keep everyone updated on my gear oil journey.....