BogMonster Posted July 11, 2007 Share Posted July 11, 2007 My Discovery is in the garage for the first bit of major-ish surgery in its 5 and a half years, just a coolant leak but seeing as it was the gasket behind the timing case there's a fair bit had to come off to get to it However - now the workshop have got it all to bits the amount of slack in the timing chain concerns me a bit. There is no danger of it jumping a tooth, but its got probably 10-12mm of movement at the mid point between the two pulleys. What's normal for this? The workshop manual for the D2 doesn't give a specified amount of slack for this item but it seems way too much for me, I would have thought no more than about half what it is. Thing is there are very few V8s here so nothing really to compare it with but it seems like a lot for 37000 miles... It's a 4.0 Thor engine but the timing chain etc is basically identical to the older ones. Any thoughts from V8-ers please? BBC and Nige in particular I don't have a timing chain nearer than about three weeks away so it is going to have to go back together for the moment anyway to get it out of the workshop, but I wonder if I ought to be planning to replace it sooner rather than later... Ta Quote Link to comment Share on other sites More sharing options...
BogMonster Posted July 11, 2007 Author Share Posted July 11, 2007 Photos with it pulled one way and then pushed the other: Thinking about it there is a slight metallic knocking at idle and has been for some time, I wonder if it could be the backlash in the timing chain clacking backwards and forwards? Quote Link to comment Share on other sites More sharing options...
Bull Bar Cowboy Posted July 11, 2007 Share Posted July 11, 2007 Stephen, That’s a typical failure of that type of chain …………….and the one that you have is stretched past its ‘sell by’ date. In practical terms there should be next to FA play in the chain. The amount of play you are exhibiting will have detrimental effect of retarding the cam timing by a small amount. Certainly on the pre-serpentine engines, the life of the chain was only about 30K …….. although of course, many go on to 150 – 200K. Many a chain has snapped due to stretch at moon mileage on the V8’s. I would say replace both chain and gears (they are not much money), however, if finances permit and you intend keeping the car then go for and aftermarket true roller chain like a ‘Cloyes’ Ian Quote Link to comment Share on other sites More sharing options...
BogMonster Posted July 11, 2007 Author Share Posted July 11, 2007 Cheers Ian, pretty much what I thought, i.e. should be almost no play. It doesn't idle near as well as it used to when new - it used to be absolutely smooth but is now "slightly fluffy" at idle, i.e. like most V8s but enough to annoy somebody like me maybe that is the cause, a bit of wobble in the timing. I think an ordinary chain will probably see out the life of the car in my hands, even the D2 has too many ECUs in it for me to want to keep it into double figures, being a pessimist on all things electronic I'm surprised it lasts such a short time though, its been religiously serviced at 6000 miles (often less - every six months) since new, and the interval on the Thor V8 is 12k using the synthetic oil, and it's not had a hard life. By a stroke of luck, it was built when Rover still had an ounce of sense about parts commonality so I have discovered that the Thor chain is actually the same part number as even the old carb'ed engines, so I might find one yet... Thanks Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted July 11, 2007 Share Posted July 11, 2007 As Ian says - thats past its sell by date and also normal for the age / mileage issue. Ian correctly also comments re the stretch in that a streched Chain has the effect of retarding the cam shaft timing, so a new decent one will perk it up no end Best are DUPLEX Chain and Gears- Cloyes are good, and with a pre streched Reynolds chain to suit makes for a proper job, The gears are full steel top and bottom, not the silly nylon junk OE fits, Unless you feel brave - stay away from vernier steel gears HTH Nige Quote Link to comment Share on other sites More sharing options...
BogMonster Posted July 11, 2007 Author Share Posted July 11, 2007 Where does one buy one of these Cloyes roller chains in the UK, and how much? The gen-ewe-whine std chain is only £13 in the price list which amazed me! I actually didn't think it had as much go as it used to either, but I thought it was just me. It still goes pretty well when you get out of a Tdi 110SW I have a pre-stretched genuine Land Rover chain for sale if anybody wants to make me an offer Quote Link to comment Share on other sites More sharing options...
geoffbeaumont Posted July 11, 2007 Share Posted July 11, 2007 Thinking about it there is a slight metallic knocking at idle and has been for some time, I wonder if it could be the backlash in the timing chain clacking backwards and forwards? Just like mine was making for a while before it did this : Quote Link to comment Share on other sites More sharing options...
Jon White Posted July 12, 2007 Share Posted July 12, 2007 Just like mine was making for a while before it did this : oooooooooooooooh good effort!!!! Quote Link to comment Share on other sites More sharing options...
BogMonster Posted July 12, 2007 Author Share Posted July 12, 2007 Yeah mine still has teeth on it tho'... Maybe some new gears as well then! Quote Link to comment Share on other sites More sharing options...
Bull Bar Cowboy Posted July 12, 2007 Share Posted July 12, 2007 Oh yes .............. always replace gears and chain as a set .................. the older gears were only about £7 each ............. I guess the newer version are not much different in price. A Cloyes true roller chain set will open your wallet to the tune of £85.15 + VAT ( I guess you don't pay that in the colonies)..... they look like this.......... Ian Quote Link to comment Share on other sites More sharing options...
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