tedsmart Posted August 14, 2008 Share Posted August 14, 2008 Hi everyone I've just had help to change the cambelt on my 300tdi defender but all was not well as far as the new crank gear which came with a kit from LRdirect would not fit by the fact the teeth on the crank gear would not fit in with the groves/ teeth on the new cam belt, when pulled around the cog, it was ever so slightly out by a couple of mil on fitting in the groves, has anyone else had this problem? I'm a bit annoyed as I had planned the job for a while now and I've had to refit the old crank gear!!!!! Also the seal behind the camshaft pully was quiet tight is this normal (seal # ERR3356) Cheers ted Quote Link to comment Share on other sites More sharing options...
Les Henson Posted August 14, 2008 Share Posted August 14, 2008 The seal should be quite a tight fit as the rubber on it has to prevent oil leaking out where it fits in the rear timing case. The teeth of the belt should fit snugly in the sprocket teeth in the same way as it does on the cam and inj pump sprockets (if the belt sits in these ok, then the sprocket is wrong). You can count the teeth and measure the diameter of the old and new sprockets to see if there is a difference. Les. Quote Link to comment Share on other sites More sharing options...
tedsmart Posted August 14, 2008 Author Share Posted August 14, 2008 The seal should be quite a tight fit as the rubber on it has to prevent oil leaking out where it fits in the rear timing case. The teeth of the belt should fit snugly in the sprocket teeth in the same way as it does on the cam and inj pump sprockets (if the belt sits in these ok, then the sprocket is wrong). You can count the teeth and measure the diameter of the old and new sprockets to see if there is a difference.Les. yeah cheers Les I understand about the seal having to be tight and that the one that came off would be loose compared but I have to admit you lost with the The: (quote: the teeth of the belt should fit snugly in the sprocket teeth in the same way as it does on the cam and inj pump sprockets (if the belt sits in these ok, then the sprocket is wrong) if I think I'm reading you right the teeth did fit well on the injection & camshaft sprockets but would not fit around the crankshaft sprocket! Well I got the feeling that if tensioned up afair bit it would have pulled it in to the teeth, but the guy helping me would have none of it saying it should have been a better fit! And because I only have the one car I needed to get it back together so as to pick the kids up from school! So the decision to put the old crank sprocket back on was made!!!!! The general condition of the old belt was pretty good what in your opinion is the chance of the old sprocket letting go (failing) how ofen are these instances occuring, any experience of them failing? Regards ted Quote Link to comment Share on other sites More sharing options...
JimAttrill Posted August 14, 2008 Share Posted August 14, 2008 If the crank sprocket is the rubbish OEM Land Rover Genuine part then there is a high possibility of the front shoulder breaking its spot welds and falling off. This normally takes the cambelt with it, with nasty results. The best thing is to use a Bearmach sprocket where the front shoulder is forged and can't fall off. I don't know anything about LRdirect parts, but it doesn't sound too good. Quote Link to comment Share on other sites More sharing options...
Les Henson Posted August 14, 2008 Share Posted August 14, 2008 If the new sprocket has less teeth than the old one, then it will alter the timing for every revolution, so it will get worse and worse until a piston hits a valve. If the diameter is different, but the tooth count the same, then it will cause premature failure of the timing belt (probably by stripping the teeth off). If you have to get the belt to fit properly by tensioning the belt excessively, then there's still a problem and you may well have over-tightened the belt anyway, which is bad. A timing belt is never stretched to fit - it's tensioned correctly to stop it vibrating on the longer runs and the shock loading of turning the inj pump and cam/crankshaft. It's difficult to state for sure if the old and new sprockets are the same, but if they have the same amount of teeth and are the same diameter, then they must be. As Jim says - the OE sprockets are prone to failure due to the spot-welded washer that is the outer lip, which eventually comes off and makes a mess of things. The single, cast sprocket that you get from Bearmach is far better. Les. Quote Link to comment Share on other sites More sharing options...
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