diesel1 Posted April 8, 2016 Share Posted April 8, 2016 My first cvrt spartan arrived thismorning, its a j60 petrol one, once its in 3rd and above, the gearbox becomes very noisey, like theres a shaft rattling about in there, the faster i go the worse it sounds. Is this normal or not. It sounds VERY bad like something going to go bang. If this is not normal i may split the shafts between the final drives and the gearbox output shafts then run through the gears to make sure it is the gearbox and not a final drive. Apart from this problem the gearbox works fine. Any thoughts on this would be very welcome. Andrew Quote Link to comment Share on other sites More sharing options...
terryb Posted April 8, 2016 Share Posted April 8, 2016 My first cvrt spartan arrived thismorning, its a j60 petrol one, once its in 3rd and above, the gearbox becomes very noisey, like theres a shaft rattling about in there, the faster i go the worse it sounds. Is this normal or not. It sounds VERY bad like something going to go bang. If this is not normal i may split the shafts between the final drives and the gearbox output shafts then run through the gears to make sure it is the gearbox and not a final drive. Apart from this problem the gearbox works fine.Any thoughts on this would be very welcome. Andrew Hi Andrew, this may be the cavitation 'growl' best heard when stationary, idling, when hot. Loudest in neutral, and reduces as you change up through the gears. Final drive may be terminally worn-and can cause serious injury should the drive fail at speed. If it is not the std growling noise, perhaps the best idea would be to break the track clear of the sprockets and test before pulling out the drive shafts-keep us posted..... Quote Link to comment Share on other sites More sharing options...
sirhc Posted April 8, 2016 Share Posted April 8, 2016 Andrew, Are you sure it's the gearbox? The fan bearings fail regularly leading to terrible sounding noises. The gearbox growl usually goes away when you get into 4th gear or above rather than worse. Chris Quote Link to comment Share on other sites More sharing options...
diesel1 Posted April 8, 2016 Author Share Posted April 8, 2016 Hi Andrew,this may be the cavitation 'growl' best heard when stationary, idling, when hot. Loudest in neutral, and reduces as you change up through the gears. Final drive may be terminally worn-and can cause serious injury should the drive fail at speed. If it is not the std growling noise, perhaps the best idea would be to break the track clear of the sprockets and test before pulling out the drive shafts-keep us posted..... Yes. i here the cavitation growl and know this is normal, something sounds as its going to fail big style the faster i go. Would it be easier to pull the final drives apart and check there ok first, seems i can get at them from the sprocket side ok Quote Link to comment Share on other sites More sharing options...
diesel1 Posted April 8, 2016 Author Share Posted April 8, 2016 Andrew, Are you sure it's the gearbox? The fan bearings fail regularly leading to terrible sounding noises. The gearbox growl usually goes away when you get into 4th gear or above rather than worse. Chris Not 100% sure its the gearbox, fan bearings are ok, its not a growling noise, it sounds like a bearing gone and the shaft dancing about in the housing over a certain forward speed, a dare not go into 7th incase something locks up and i lose some teeth Andrew Quote Link to comment Share on other sites More sharing options...
terryb Posted April 8, 2016 Share Posted April 8, 2016 Yes. i here the cavitation growl and know this is normal, something sounds as its going to fail big style the faster i go. Would it be easier to pull the final drives apart and check there ok first, seems i can get at them from the sprocket side ok If it speed rather than engine rpm related then it points to drive train-drop the track (slack off bleed bolt on grease ram, remove one pin with drift) Sprockets should offer resistance to being turned, but smooth, with no up/down play in bearing. Drive up through gears-any mechanical noise will resonate from the front bulkhead. If the noise has gone, then its track-track alignment issues causing the noise. Quote Link to comment Share on other sites More sharing options...
diesel1 Posted April 8, 2016 Author Share Posted April 8, 2016 If it speed rather than engine rpm related then it points to drive train-drop the track (slack off bleed bolt on grease ram, remove one pin with drift) Sprockets should offer resistance to being turned, but smooth, with no up/down play in bearing. Drive up through gears-any mechanical noise will resonate from the front bulkhead. If the noise has gone, then its track-track alignment issues causing the noise. Its not engine speed related, its forward speed related, i will drop the tracks off the spockets and investigate. Thanks Quote Link to comment Share on other sites More sharing options...
diesel1 Posted April 9, 2016 Author Share Posted April 9, 2016 So far ive split the tracks from the sprockets so no drive, run the engine through all the gears, held it in 7th at 4000rpm, it runs very sweet and quiet, ive checked axle arm bearings, road wheel bearings and track adjuster idler wheels, all the good. The spockets are worn a little, not much, but im swapping both sprockets to the opposite sides so they are not worn as they have not been turned round before, not much more i can do, the tracks are within there wear limits as stated in the book. Will give a update when shes back together and road tested. Andrew Quote Link to comment Share on other sites More sharing options...
terryb Posted April 9, 2016 Share Posted April 9, 2016 check outer sprocket is in line with inner one (small hole below one tooth must line up with other sprocket) rubber tyres on sprocket wheels are good. use a straight edge on all road wheels and rear idlers to check they are parallel to hull. Most likely culprit could be a failed rubber bush(es) in the track, throwing it out of line Quote Link to comment Share on other sites More sharing options...
terryb Posted April 9, 2016 Share Posted April 9, 2016 sorry, should have added to look at the inner and outer sides of the teeth on the sprocket to see if the track has been throwing out of line Quote Link to comment Share on other sites More sharing options...
diesel1 Posted April 9, 2016 Author Share Posted April 9, 2016 check outer sprocket is in line with inner one (small hole below one tooth must line up with other sprocket) rubber tyres on sprocket wheels are good. use a straight edge on all road wheels and rear idlers to check they are parallel to hull. Most likely culprit could be a failed rubber bush(es) in the track, throwing it out of line Yes, put the sprockets back on then found them not to line up, this was soon rectified. The edges on the sprockets are fine. Shes all back together and ready for a road test tomorrow so fingers crossed. Thankyou for all the advice, will let everyone know how the road test goes. Andrew Quote Link to comment Share on other sites More sharing options...
Grasshopper Posted April 11, 2016 Share Posted April 11, 2016 If you do end up having to split a final drive to check the bearings, you have to drop the whole assembly out of the hull as some of it dismantles from the outside and the rest dis-assembles from the inside of it. I have dropped final drives out by myself using enough timber as packing to get them to floor level. Easier with 2 people though! Vince Quote Link to comment Share on other sites More sharing options...
diesel1 Posted April 11, 2016 Author Share Posted April 11, 2016 If you do end up having to split a final drive to check the bearings, you have to drop the whole assembly out of the hull as some of it dismantles from the outside and the rest dis-assembles from the inside of it. I have dropped final drives out by myself using enough timber as packing to get them to floor level. Easier with 2 people though! Vince Seems its the tracks making a lot of noise, its a little quieter now, one of the sprockets seem to be 5mm ish out of alienment looking down the road wheels, track running slightly off centre but not a lot, will sort this out this week. Quote Link to comment Share on other sites More sharing options...
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