TefkaC Posted May 23, 2008 Share Posted May 23, 2008 SAAB 95 estate 96 saloon, I had a 95 that would seat 7 with a fold down seat in the rear. You could drive in fixed or freewheel depending on road conditions, there was a lever in the cab to the gear box that could disengage the fixed wheel drive(those were the days). In the UK if the car is not fitted with this it is totally illegal to coast, not sure in france though. Charlie......... Link to comment Share on other sites More sharing options...
Ron Avery Posted May 23, 2008 Share Posted May 23, 2008 You can freewheel for short distances without doing any harm to a car or van, but with those old cars the key phrase was this "........but disengaged the gearbox from the axle on the overrun "If you freewheel too much in a short space of time or for too far you will damage the gearbox as it will not lubricate itself and the short term gain could be long term pain[:(] Link to comment Share on other sites More sharing options...
mint Posted May 23, 2008 Share Posted May 23, 2008 Thank you, Ron. I knew there was a catch but I wasn't sure what and I certainly couldn't have explained it to Wooly in a way that he would have accepted! Link to comment Share on other sites More sharing options...
powerdesal Posted May 23, 2008 Share Posted May 23, 2008 [quote user="Ron Avery"]You can freewheel for short distances without doing any harm to a car or van, but with those old cars the key phrase was this "........but disengaged the gearbox from the axle on the overrun "If you freewheel too much in a short space of time or for too far you will damage the gearbox as it will not lubricate itself and the short term gain could be long term pain[:(][/quote]?????????????????????????????????????????????????????????????????????????????????Every gear box I have ever worked on has been partially filled with oil, independently of any other component and has been "splash lubricated", now obviously some hi tech motors have gear box oil pumps but they are, I suspect, not the norm and I suspect the said oil pump is driven by rotation of the gearbox.When you coast or freewheel, the gear box mainshaft is not being driven by the engine, ie in neutral or clutch disengaged. The gear box is of course still connected to the driven wheels via the diff but I am at a loss to understand how a splash lubricated box can be damaged by being turned in its normal direction of rotation. Perhaps you could explain for my further engineering education. Link to comment Share on other sites More sharing options...
woolybananasbrother Posted May 23, 2008 Share Posted May 23, 2008 I am not an engineer but I would like to ask what happens to an engine when it is idling then? Coasting is just leaving the engine in neutral isn't it? Does this mean that if an engine is in neutral for more than a very short time, the gearbox is getting damaged, at least potentially? Link to comment Share on other sites More sharing options...
powerdesal Posted May 23, 2008 Share Posted May 23, 2008 Wooly,When a car is in neutral and not moving, the gearbox is not being turned even when the engine is running, or rather the gearbox output shaft is not being turned. The main input shaft is in fact turning but the gears are not selected. When you declutch you physically disconnect the engine from the gearbox allowing the gears to be selected, the synchromesh "cones" spinning up the layshaft to match the mainshast, when the clutch is released the engine drive is "solid " through the gear shafts to the propshaft then the diff then the wheels.When coasting in neutral, the wheels are rotating and driving the diff and hence the propshaft and the layshaft. The mainshaft is, assuming the clutch is not depressed, still being rotated by the engine at low rpm, but not "meshed" with the layshaft.When going back into gear after coasting, the clutch is depressed to take drive away from the mainshaft and allow the synchro to link the main and layshafts.IMHO the lubrication argument is false because the gearbox gear and bearing lubrication is continuous as long as anything is turning in the box because the gears, shafts and bearings are in the oil or are being splash fed. The above is of course a gross simplification given the increasing complexity of modern gearboxes, but is, I believe correct in principle. Link to comment Share on other sites More sharing options...
AnOther Posted May 23, 2008 Share Posted May 23, 2008 [quote user="Ron Avery"]If you freewheel too much in a short space of time or for too far you will damage the gearbox as it will not lubricate itself and the short term gain could be long term pain[:(][/quote]What a load of nonsense Ron, go and hang your head in shame [:'(]Apart from automatics the one and only car I have ever head of that could potentially have it's gearbox damaged by freewheeling, or rather the equivalent, i.e. being towed without the engine running and turning it or by prolonged coasting, is the Triumph TR7 because it had a pumped oil system, not just immersion/splash. Link to comment Share on other sites More sharing options...
woolybananasbrother Posted May 23, 2008 Share Posted May 23, 2008 Steve, have you been at the saddiqui or the flash? Not a word do I understand, nor does Ron. Just my gearbox please on a Meriva. Is the thing safe if I slip out of gear? Link to comment Share on other sites More sharing options...
powerdesal Posted May 23, 2008 Share Posted May 23, 2008 Just the white grenache. [:P]Yes, if its a manual box. Link to comment Share on other sites More sharing options...
woolybananasbrother Posted May 23, 2008 Share Posted May 23, 2008 I fancy a return to the Gulf if they'll have me. Permanently pissed. Thanks for the clarification. I shall continue my habit then. Link to comment Share on other sites More sharing options...
powerdesal Posted May 23, 2008 Share Posted May 23, 2008 I will swap anytime, cant wait to leave. [B] Link to comment Share on other sites More sharing options...
Ron Avery Posted May 23, 2008 Share Posted May 23, 2008 [quote user="ErnieY"][quote user="Ron Avery"]If you freewheel too much in a short space of time or for too far you will damage the gearbox as it will not lubricate itself and the short term gain could be long term pain[:(][/quote]What a load of nonsense Ron, go and hang your head in shame [:'(]Apart from automatics the one and only car I have ever head of that could potentially have it's gearbox damaged by freewheeling, or rather the equivalent, i.e. being towed without the engine running and turning it or by prolonged coasting, is the Triumph TR7 because it had a pumped oil system, not just immersion/splash.[/quote]The advice I gave was based on the recommendation that rear axle drive shafts and/or carden (prop) shaft should be removed from any rear wheel drive vehicle having a front suspended tow of over 3 miles, so as not to damage the gearbox. Perhaps that only applies to rear wheel drive vehicles, heavy lorries and buses, if it does not apply to modern cars then I apologise for any misinformation. Link to comment Share on other sites More sharing options...
AnOther Posted May 24, 2008 Share Posted May 24, 2008 I'd be very interested to see where this advice or reccommendation comes Ron as it makes no sense at all and is entirely illogical, as is any distinction between front or rear wheel drive vehicles [8-)] Link to comment Share on other sites More sharing options...
Sunday Driver Posted May 24, 2008 Share Posted May 24, 2008 I seem to remember back in the 60's when I were a lad, you had to do that when towing automatics - which were all mostly RWD in those days.Of course, I wasn't interested in automatics at that age (got one now, though), so I could be wrong........[;-)] Link to comment Share on other sites More sharing options...
Sunday Driver Posted May 24, 2008 Share Posted May 24, 2008 Found this post on the UK Pajero/Shogun owners club forum:When towing an automatic, you don't trail the driving wheels or you'll damage the transmission, even on a short journey. This means that a (broken down) 4WD auto should be recovered on a flat-bed, not towed. Where this is not possible, I have known the driveshafts to be disconnected, tied out the way, and the vehicle towed. But that would be at your own risk. If yours breaks down, in order to prevent a longer wait, let the Recovery firm know that you have a 4WD automatic, when making the initial call. Link to comment Share on other sites More sharing options...
AnOther Posted May 24, 2008 Share Posted May 24, 2008 Quite so SD and just as valid now as then.Are there many FWD automatics these days, and I don't include variomatics which employ a belt and variable pulley system?For what few there may be I would imagine that, for all intents and purposes, they are untowable unless suspended.PS: What's any of this got to do with diesel any more [blink] Link to comment Share on other sites More sharing options...
tegwini Posted May 24, 2008 Share Posted May 24, 2008 I would like to know the average price of diesel in France - trip booked for beg. July.If it makes people feel better, diesel in Wiltshire is £1.27+ per litre. That's the cheapest I have seen it here.We won't be helped by the exchange rate on our next trip, but it is still more expensive here than France. It usually is. I suppose there is plenty of it around - truck drivers here are not like the French ones. That's why we pay more. Greedy Gordon needs - or wants the extra he's getting at the moment.RegardsTegwini Link to comment Share on other sites More sharing options...
Clair Posted May 24, 2008 Share Posted May 24, 2008 You can check recent or current prices in your chosen area here: http://www.prix-carburants.gouv.fr/index.php Link to comment Share on other sites More sharing options...
powerdesal Posted May 25, 2008 Share Posted May 25, 2008 How strange that the site doesn't show Leclerc at Boulogne. We always fuel up there when travelling in either direction. Link to comment Share on other sites More sharing options...
Clair Posted May 25, 2008 Share Posted May 25, 2008 Did you see that you can filter the results by fuel brand and town fro any given departement?You can also register with the site and keep a list of favourites petrol stations so you can keep an eye on the prices? Link to comment Share on other sites More sharing options...
tegwini Posted May 25, 2008 Share Posted May 25, 2008 Thanks ClairPresently looking at it - but it is a bit scary - it's not that long ago when I paid 34p per litre. The roads seem a lot quieter in southern Wiltshire- perhaps people are starting to stay home more. France is still cheaper by about 11p per litre, and sterling's depreciation has partly caused this. At Christmas time the difference was about 20p. Greedy Gordon is not helping here.RegardsTegwini Link to comment Share on other sites More sharing options...
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