trojan Posted March 23, 2007 Share Posted March 23, 2007 evening fellas , i could do with a bit of advise . a friend of mine has just dumped his problem on my door step and i could do with a couple of ideas before trying to sort it out . he has a discovery 300tdi with an r380 gearbox , on his way home from work he lost all drive , suddenly and without drama . i'v had a quick look see and cant decide what the problem is . the clutch feels normal and gears feel like they can be selected ok , i'v checked that the high low stick is in gear and it seams to be . their is a slight grinding noise when you lift off the clutch , but this is very quiet and i could only just hear it . any ideas will be welcome as i have'nt really any time to be messing with it . thanks in advance . Quote Link to comment Share on other sites More sharing options...
BogMonster Posted March 23, 2007 Share Posted March 23, 2007 2 most likely possibilities: 1) centre gone out of the clutch 2) mainshaft gear stripped A distant 3rd is a snapped mainshaft. I'm assuming you have tried all gears and reverse in high and low range, with and without diff lock engaged, and that you've looked underneath to make sure none of the propshafts are spinning freely ... if not then check those things first. If one of the props is spinning freely then you have a diff or halfshaft problem. If the vehicle is newer than 1996 it probably isn't the mainshaft splines but if it is older, you need to check that by taking the PTO cover off the back of the transfer box and taking the gear out. If the splines are chewed up it will be an obvious rusty gungy mess. If they are not, put the vehicle in gear and try driving, if the clutch centre has gone the mainshaft won't turn. Report your findings and we'll see where to go from there Quote Link to comment Share on other sites More sharing options...
trojan Posted March 23, 2007 Author Share Posted March 23, 2007 thanks for the quick answer , its a bit dark to be rolling about on the floor but i'll have a look in the morning . the disco is a 95 m reg and yes i tried all gears , high and low , and thier was no drive . he said it just happened and thier was no dramas to report so i'm hoping its the transfer gear . would you have expected some kind of obvious noise or occurance if it was any of your suggestions . Quote Link to comment Share on other sites More sharing options...
BogMonster Posted March 23, 2007 Share Posted March 23, 2007 If it is a 95MY my money would be on the mainshaft splines. Sometimes/usually they go with a bang but not always. If you know the sort of bang it makes when a t-box jumps out of high or low range, that is what it sounds like when it goes under load but it could just be a bad gearchange or something. Start with the PTO cover anyway it is easy to get off and it will be immediately obvious if that is the problem. If so it will need a gearbox rebuild with a new mainshaft and fit the new type input gear in the t/box which has oil drillings in it so the problem will never reoccur. May be as well to get an exchange gearbox from Ashcrofts and I would fit a new clutch at the same time, since it is a gearbox out job and you are 98% of the way there already. Quote Link to comment Share on other sites More sharing options...
trojan Posted March 23, 2007 Author Share Posted March 23, 2007 ok , i'll have a proper check in the morning and i'll let you know what happens , at least now i have a start point , once again thanks for your help . rick..... Quote Link to comment Share on other sites More sharing options...
MRWOO Posted March 23, 2007 Share Posted March 23, 2007 The exact thing happened to me, all was fine then I lost drive. Gear selection was perfectly normal but no drive in any gear hi or low or in dif lock. Reason = centre of clutch spun out The clutch plate was actually fine but not much use when the centre has spun loose. Rich Quote Link to comment Share on other sites More sharing options...
trojan Posted March 23, 2007 Author Share Posted March 23, 2007 well , i'v got a horrible feeling thats what this is , i dont mind doing the job but i could have done with it next week , i'm gonna have to start stacking vehicles i'v got no room at all Quote Link to comment Share on other sites More sharing options...
JimAttrill Posted March 24, 2007 Share Posted March 24, 2007 If it's the centre of the clutch you are lucky, for that is cheaper to fix than a new gearbox mainshaft. It's all a pain though. Quote Link to comment Share on other sites More sharing options...
trojan Posted March 25, 2007 Author Share Posted March 25, 2007 had a good look and i'm now sure its the clutch centre that's the problem , so now i have to find the time to sort it , and as it happens he's in no rush , thank god . once again thanks everybody for your help , i'd have struggled to diagnose the problem without you . the jobs always easier when you have the right info to start with . rick...... Quote Link to comment Share on other sites More sharing options...
BogMonster Posted March 25, 2007 Share Posted March 25, 2007 If you have time it may be worth taking a look at the mainshaft splines anyway - you wouldn't want it to go bang the following week would you Quote Link to comment Share on other sites More sharing options...
trojan Posted March 25, 2007 Author Share Posted March 25, 2007 If you have time it may be worth taking a look at the mainshaft splines anyway - you wouldn't want it to go bang the following week would you ahh , see i'm learnin already , i'v got me name on a spare r380 just in case i'm wrong cos i was wrong once , only once tho !! Quote Link to comment Share on other sites More sharing options...
streaky Posted March 26, 2007 Share Posted March 26, 2007 Something that is often overlooked when this kind of thing happens is that the splines inside the hub flange have stripped. This leaves everything else spinning and you think you have a major problem on your hands. Engaging the central difflock will get you moving on the remaining axle. S Quote Link to comment Share on other sites More sharing options...
BogMonster Posted March 26, 2007 Share Posted March 26, 2007 It is - I know somebody that pulled half a vehicle to bits only to discover a stripped drive flange. There was language when I pointed it out Hence the need to start by looking underneath to make sure there aren't any propshafts spinning. If there is a prop spinning freely, then the problem is at that end, something the person I "helped" completely failed to check Quote Link to comment Share on other sites More sharing options...
nookybear Posted March 26, 2007 Share Posted March 26, 2007 .....must be a Bolton thing this loss of transmission lark. Followed me all the way to the Isle of Man from sunny Great Lever !!.........got the IDENTICAL problem meself now. In first at the lights uphill...set off then heard a loud thud then I started to roll backwards in forward gear. Can start up the Disco (300Tdi '94) in any gear in any drive. No props turn. Took the Bogmonsters' advice and tried to take off the t/fer box upper cover - all bolts 'wleded' on tighter than the lock on the wife's purse. Had to drain the thing then remove the bottom cover, that came off like her knickers, all gears/teeth are intact & no metal in the oil either. Strange thing is, in neutral with engine running all gears in t/fer box turn slowly and I can stop them with a bit of wood very easily. Not tried it in gear yet........any suggestions will be gratefully received.......please tell me the clutch centre (full kit fitted last July) and not the splines....Cheers, Tony. Quote Link to comment Share on other sites More sharing options...
BogMonster Posted March 26, 2007 Share Posted March 26, 2007 Erm... Assuming the vehicle is not moving ... the tbox gears should not be turning! What happens if you put it in diff lock? Quote Link to comment Share on other sites More sharing options...
nookybear Posted March 26, 2007 Share Posted March 26, 2007 Erm...Assuming the vehicle is not moving ... the tbox gears should not be turning! What happens if you put it in diff lock? Not tried that yet, only dunnit with the gearbox/tbox in neutral as ran out of light and time. I'll give it a go tomorrow after work and let you know the outcome. Thanks for the quick response ! Quote Link to comment Share on other sites More sharing options...
nookybear Posted March 27, 2007 Share Posted March 27, 2007 Erm...Assuming the vehicle is not moving ... the tbox gears should not be turning! What happens if you put it in diff lock? Tried earlier this morning and with the engine running, Diff Lock in high and gearbox in 1st, all the gears in the tfer box were static/locked. I couldn't move them with the bit of wood I had been using apart from a bit of play. I moved the front prop by hand and the gears in the tfer box moved slightly as above as I expected (?). The back of the gearbox did sound a bit noisy though with the diff cover off. Another thing I noticed is that the higher the gear when changing (which I can do as it's on ramps/axle stands with no transmission), ie 1st to 5th in lock, the noisier the sound in the cab got (as though gears trying to mesh) but not very loud at all more of a rumble. No judders though. ....ideas please matey, many thanks, Tony Quote Link to comment Share on other sites More sharing options...
BogMonster Posted March 27, 2007 Share Posted March 27, 2007 Bit confused. So you are now saying that when you try driving it, the tbox gears do NOT move since you had a fiddle with high/low? With the PTO cover plate off the back of the transfer box, and the vehicle in (say) 1st high and trying to drive, does the gearbox mainshaft turn or not? And if the shaft turns, does the gear turn with it? I would say it is either the clutch centre or the mainshaft splines, if the shaft is turning inside the gear then it is the splines, if the shaft is not turning when the vehicle is in gear and driving, then it is probably the clutch though there are other possibilities - early 300Tdi vehicles were prone to snapping mainshafts which left no drive at all, but I would expect any "weak" ones to have long since failed. If it is clutch or gearbox you are going to have to take the gearbox out anyway so it should be fairly obvious once it gets to that stage. Quote Link to comment Share on other sites More sharing options...
nookybear Posted March 27, 2007 Share Posted March 27, 2007 Mainshaft does not turn when done as you described ie in 1st in high range or any other gear or range for that matter !! All gears are solid with just a bit of play seen when moving the front prop back and forth. The only time the shaft turns along with the gears is when both boxes are in neutral and it's like when a cement mixer is on the stand instead of its wheels, you can see the wheels turn very slowly. I can stop the turning too with the bit of wood I mentioned earlier as it doesn't take much pressure. Box out me thinks anyways.... .....Twas the splines after all. Teeth like a broken fence. Quoted £750.00 for complete o/haul and new imput gear to t/fer. Spare R380 with t/fer anyone? Quote Link to comment Share on other sites More sharing options...
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