alex park Posted November 9, 2007 Share Posted November 9, 2007 Having just sorted out my elctrical drain on my battery, i thought it was about time i took a look at a problem that i have had with the car for a while. It is a Disco v8 97 with i believe the R380 gearbox. the Problem on start up the box sounds rattly and once the revs have dropped to idle there is a continuous grumble from the gearbox which dissappears when i depress the clutch. however on some occasions it does not dissappear but is exacerbated and sounds like gears are trying to intermesh. however pumping the clutch will more often than not make this go away. once the revs are settled the car goes into all gears fine however once i start lets say reversing out of my drive and have to dip the clutch to stop for traffic the gears sound like they are again failing to mesh properly and grind like hell, to a point where i have to take it out of gear, lets the revs settle and try again. once driving steadilly i have no problems other than it sounds grumbly in second gear and fourth gear more so than the rest. approaching any red lights or stop signs and i have to dip the clutch, there again is the sounds of the gears not meshing and the revs rise, where again i have to take it out of gear and let the revs settle. I'm fortunate (or unfortunate) that i have no need to drive this week or next but have decided to buy a cheap runnabaout cos i have to go back to work soon. any clues as to what may be the cuplit or is it a multitude of sins? i know the clutch was changed about 50k ago,the milage has all been motorway and no offroading in it. Alex Quote Link to comment Share on other sites More sharing options...
BogMonster Posted November 9, 2007 Share Posted November 9, 2007 Release bearing (grumble), the springs in the friction plate (rattle) or more likely both would be my guess. Quote Link to comment Share on other sites More sharing options...
alex park Posted November 9, 2007 Author Share Posted November 9, 2007 engine and gearbox out? recon box and new clutch? Quote Link to comment Share on other sites More sharing options...
wrcwrc Posted November 9, 2007 Share Posted November 9, 2007 gearbox out yes, recon box not necesarily no. what bogmonster has described is basically just a 3 peice blutch kit change tbh, not the end of the world at all. Quote Link to comment Share on other sites More sharing options...
alex park Posted November 9, 2007 Author Share Posted November 9, 2007 so new clutch, release bearing. i thought maybe the mainshaft bearing or layshaft might have been worn? forgive my ignorance. alex Quote Link to comment Share on other sites More sharing options...
DiscoClax Posted November 10, 2007 Share Posted November 10, 2007 Firstly, silly question. Does the gearbox (and transfer) have the right amount of the right oil in it? A low oil level (or too thin) can allow this noise. Assuming the oil is OK.... From your description, it sounds very much like you have NRO (neutral roll-over) noise issues. This is caused by the slight speed fluctuations caused by engine firing accelerating and decelerating the gears in the 'box and causing them to slap (backlash), which manifests as a rattle. Low idle speeds exacerbate this. Sounds much worse than it is, and does no damage, but can drive you nuts. When you clutch in, you break drive and the noise stops as the box is no longer getting excited by the engine. Punching the clutch in and out can alter the specific positioning of the components within the clutch and improve or degrade the isolation. I've spent years as a professional driveline engineer tuning clutches and tweaking engine calibrations to minimise this noise. Overfilling the gearbox oil level can help reduce this noise, too (but can open a Pandora's box of other issues). Problem is much easier to fix on an eight than a big six or (shudder) four-pot, and don't get me started on diesels The clutch disc has a torsional spring pack and friction dampers built into the centre. Unsure of the exact LR design, might also have an idle-stage pre-damper with very light springs. Probably not though, as the V8 is a smooth, even-fire beast - not like those horrible diseasal things . This description is pretty generic but applies to all conventional clutch systems. Likely cause of the noise is the hysteresis on the frictional damper changing dramatically due to wear or a failure of an isolation spring or hub component or similar. Either way, it's not serviceable - requires a new clutch disc. Recommendation would be to pop the box out and put a new clutch kit into it. Not overly expensive. Ideally, try and source a clutch from the OE (original equipment) manufacturer as it'll be tuned right. Most aftermarket ones are generic and might not isolate properly, but they are generally a lot cheaper. Often the OE manufacturer sells the exact same clutch as originally fitted, but not in the massively expensive, nice green and white LR box. I'm not sure who the OE is for LR, Sachs perhaps? Hopefully another forum member can advise. You can take the opportunity to wind the box over by hand, back and forth in neutral and each gear to assess play and condition while it's out. Input and output bearing play, seals, etc. Mind you, the box is probably fine, just seems noisy due to lack of engine isolation due to a dodgy clutch and/or throw-out bearing. Good luck Quote Link to comment Share on other sites More sharing options...
Les Henson Posted November 10, 2007 Share Posted November 10, 2007 Sounds like a typical thrust bearing/clutch springs problem to me. This noise can go on for yonks without getting worse or better Les. Quote Link to comment Share on other sites More sharing options...
alex park Posted November 10, 2007 Author Share Posted November 10, 2007 when i bought the car from a dealer a few years ago, it developed this "niose and lack of clutch friction" a very short time after buying from the dealer. it wasnt a main landrover dealer but a 4x4 dealer non the less. I lost all drive except in low range and the closest place i could get too was a main landrover dealer in HULL. whilst there i contacted the initial dealer and complained like hell (it was only a week after all) and he told me that he would collect it from the Main dealer and sort it out. The main dealer already had the box out and told me it was a broken clutch fork cuasing the problem. so.... i informed the initial dealer who replaced the clutch. the noise soon returned however. stupidly perhaps i didnt return it to the initial dealer as i was so frustrated. but learnt to live with it. so, all fluid are ok. gearbox has ATF dextron 3 transfer box has ep90. so if i'm gonna drop the box out and replace the clutch, what actual parts will i need to buy. and where is the best place to get them. and what other components would be recommended to be changed/upgraded if the box is out? thanks for the input everyone Quote Link to comment Share on other sites More sharing options...
Les Henson Posted November 10, 2007 Share Posted November 10, 2007 Once you have identified that the clutch is the problem, then a Borg & Beck kit comes with plate, cover, and thrust bearing. If the clutch fork is not reinforced, then I suggest you get a reinforced item. Also the little U-shaped clip that holds the thrust bearing to the fork, and the clip that holds the slave pushrod to the end of the fork (use a cable tie as well). Have a look to see if there is any oil running down behind the flywheel, which would require removal of the flywheel to replace the crankshaft rear seal. The thrust bearing runs on a sleeve that is attached inside the gearbox - look for steps in the metal that would prevent the bearing from sliding along it smoothly. Clean it up and apply a thin layer of coppaslip grease. Les. Quote Link to comment Share on other sites More sharing options...
lynall Posted November 11, 2007 Share Posted November 11, 2007 Gave a mate at work a hand to change the clutch in his p38 diesel and there was loads of lift in the input shaft but he said it made no noises so we changed clutch and gearbox oil and off to Poland he went! Lynall Quote Link to comment Share on other sites More sharing options...
BogMonster Posted November 11, 2007 Share Posted November 11, 2007 Gave a mate at work a hand to change the clutch in his p38 diesel and there was loads of lift in the input shaft but he said it made no noises so we changed clutch and gearbox oil and off to Poland he went! Did he come back? Quote Link to comment Share on other sites More sharing options...
Jason2 Posted November 11, 2007 Share Posted November 11, 2007 when i bought the car from a dealer a few years ago, it developed this "niose and lack of clutch friction" a very short time after buying from the dealer. it wasnt a main landrover dealer but a 4x4 dealer non the less.I lost all drive except in low range and the closest place i could get too was a main landrover dealer in HULL. whilst there i contacted the initial dealer and complained like hell (it was only a week after all) and he told me that he would collect it from the Main dealer and sort it out. The main dealer already had the box out and told me it was a broken clutch fork cuasing the problem. so.... i informed the initial dealer who replaced the clutch. the noise soon returned however. stupidly perhaps i didnt return it to the initial dealer as i was so frustrated. but learnt to live with it. so, all fluid are ok. gearbox has ATF dextron 3 transfer box has ep90. so if i'm gonna drop the box out and replace the clutch, what actual parts will i need to buy. and where is the best place to get them. and what other components would be recommended to be changed/upgraded if the box is out? thanks for the input everyone I would change the spigot bearing at the same time (holds box main shaft into crank/back of flywheel) only 80p.To get the old one out fill old bearing (It's actualy a bronze bush) with grease and place approx sized bar into hole, a nice tap with a hammer will compress the grease and push old bearing out! Quote Link to comment Share on other sites More sharing options...
alex park Posted November 12, 2007 Author Share Posted November 12, 2007 Les, in the picure i have arrowe what i believe you mean about tie wrapping the clips on. can you tell me if those are the areas you mean. As the fork acts on a pivot and pulls the thrust bearinf ect is it essential to get the tiewarps in the correct position to make sure that they pull it back equally in the proper direction. clutch thanks in advance Alex Quote Link to comment Share on other sites More sharing options...
Les Henson Posted November 12, 2007 Share Posted November 12, 2007 Only one tie on the small end of the clutch fork. You put it there because the clip isn't very strong and may break in the future if you have to replace the clutch slave cylinder. Les. Quote Link to comment Share on other sites More sharing options...
alex park Posted November 13, 2007 Author Share Posted November 13, 2007 thanks very much for that Les. looking at Mr Ashcrofts website (who i know is well respected on this forum and through the industry). It states that the V8 clutch fork does not wear on the V8, but even on here there seems to be quite a number that do. Ashcroft Borg & Beck Clutch Alex Quote Link to comment Share on other sites More sharing options...
Les Henson Posted November 13, 2007 Share Posted November 13, 2007 I thought the clutch fork was the same for all. Is it cast iron or something then does anyone know? Les. Quote Link to comment Share on other sites More sharing options...
alex park Posted November 13, 2007 Author Share Posted November 13, 2007 Dunno, but scared myself to death looking around the NET for a clutch fork. looked on this site and went through all the ordering process until it showed me the picture of what i was ordering..... clutch fork i just hope they got the picture wrong. Alex Quote Link to comment Share on other sites More sharing options...
Les Henson Posted November 14, 2007 Share Posted November 14, 2007 Dunno what that thing is but it's definitely not a clutch fork. If it is a cast steel item, then it'll not wear out. Les. Quote Link to comment Share on other sites More sharing options...
First_Fleet Posted November 14, 2007 Share Posted November 14, 2007 Is it cast iron or something then does anyone know? Jim Attrill stated once, that the V8's are cast & don't wear like the pressed ones. No doubt Jim will add to this thread. Never having studied this, but is it possible to get some grease on to the ball from outside the housing? Quote Link to comment Share on other sites More sharing options...
alex park Posted November 14, 2007 Author Share Posted November 14, 2007 I actually solved it Les by getting hold of one you have already strengthened from Disco Jim of this forum. Alex Quote Link to comment Share on other sites More sharing options...
alex park Posted November 15, 2007 Author Share Posted November 15, 2007 just crawled underneath the car to double check all the fluids and investigate another minor rattle and found the two upper nearside crossmember bolts completely undone. I can only think that when the clutch was last done that they were'nt refitted properly!! As one was completely the wrong way round. Pah! alex Quote Link to comment Share on other sites More sharing options...
Les Henson Posted November 16, 2007 Share Posted November 16, 2007 Makes you wonder what else hasn't been done properly. As for the bolt the wrong way round - I reverse bolt positions quite a lot on various things - it makes the job easier to do sometimes and providing any protruding thread doesn't damage anything else - it doesn't matter. Les. Quote Link to comment Share on other sites More sharing options...
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