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Cam belt saga continues


cefn_bran

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Hello all!

Following a snapped cam belt that only mashed 6 pushrods and snapped two rockers ;) , everything is back together, but there is a problem...

When turning over the engine (with timing cover off), the cam belt sneaks forward...about half way off the sprockets after just a couple of dozen turns. I inspected the inside of the timing cover and found a groove deep enough to run scalextrix on. Don't really want to cover this up, 'cos the belt is simply going to wear away again (the mashed belt was down to about half its original thickness when the teeth gave way).

I strongly suspect that this 1994 300Tdi hasn't had the after market conversion to correct the injector pump misalignment, but how do I tell? Could this be the problem or is there something else?

Anyone got any experience of this?

Thanks

Ivan

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The beginning of this thread shows the kit that is the modification for the 300TDi engine.

http://forums.lr4x4.com/index.php?showtopic=6943

Les. :)

Hi Les

I got this stuff from Paddocks. Specifically asked for the conversion stuff as I didn't know if it had been done. They supplied me with the bracket and two rollers along with gasket and belt, though no new bolts, so I guess that I could consider that this disco is now converted. Don't see, however, how this bit of kit can correct the injector pump misalignment though. I'm sure I've read somewhere that there is a new timing cover involved along with other stuff, and someone has spoken to me about having to take the injector pump off. So now I'm mightily confused. It would appear that I've got a converted engine that has a belt slipping off. Aaarrggghhh.

Help.

Ivan

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You are right, the older engines needed a full kit STC4095K including the timing cover and a new bracket for the injector pump plus all the pulleys etc found in the smaller kit for later 1997 engines. The way to tell is that if there is a lip on the crankshaft pulley (to retain the belt - as seen on the crank pulley in the thread Les linked to), you have one of the kits fitted, if the lip is on the tensioner/idler (I forget which one) then you don't... I have no idea how to tell if the timing case has been renewed for the big kit though :(

The belt should not "sneak" forwards at all - the lip on the pulley should stop this? Can you post a pic of what is happening, have you got a mixture of pulleys fitted so that none of them have a lip? in which case it needs sorting out!

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I'll try sort some pics out in the morning as I've no digi camera. The crank shaft pulley only has a lip at the back, not the front, so I guess this is an old one and I've got an unmodified engine. Ahh, well!

Found this quote whilst crawling "£176 for an extensive modification kit STC4095K including not only the new belt but also a new timing cover, idler pulleys and crankshaft sprocket with belt retaining lips." (No mention of injector pump bracket, though). I'm thinking that this full kit is a main dealer part, as paddocks don't appear to list it on t'interweb, though I'll give them a call on Monday.

Meanwhile...

Thanks for your helps

Ivan

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Didn't manage to get hold of a digi camera today.

As you say the crankshaft pulley should have either none or two lips, do you think I am safe to assume that replacing the pulley with a two-lipped one (a full mouth?) and forgetting about the new injector pump bracket will suffice, or should I replace the injector pump bracket too? My main fear would be the belt climbing up the lip if there is still loads of pressure for the belt to drift forwards, or the belt grinding away on the front lip.

Hmmm

Ivan

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  • 2 weeks later...
Should have lip on either none or both ends on crank pulley, suspect it has broken off (they are only spot welded and do break) so you need a new crank pulley!

That happened to a mate of mine 500kms after fitting the ERR4096K (Genuine LR) kit, with disastrous results. LR refused to pay, of course. We only fit Bearmach kits now, everything is the same except the pulley has a forged lip which can't fall off.

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Interesting. LR no longer do the kits and so these days we get ours from Bearmach too, but I thought they still had the rubbishy spot welded crank pulley - must check!

I know somebody that lost the front lip off the crank pulley too, a week after fitting the kit. Fortunately it was somebody who wouldn't bring their vehicle in to us and did it himself "so it was done properly" so there was a bit of tittering when it went pop after a week and came in to us on the end of a tow rope to have another one :)

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Hi Guys - got an anomaly!

OK - put pin in flywheel through wading plug. Crankshaft woodruff key is 90 degrees advanced though. That doesn't seem right.

Any ideas? Which is right - use the flywheel or the crankshaft?

If I leave the pin in the wading plug, should I simply return the pump and cam back 1/8 turn to line them up, or should I line up the woodruff key and leave the flywheel 90 deg out?

Erm... help.

Ivan

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There is a 'false' hole in the injector pump about 30 deg out from the other. If you time it like that it will never start. BTDT. As they say in the manual you should put all the pins in before taking the belt off and not turn the engine. I learnt my lesson the first time. The timing only has to be a tiny bit out for the engine not to start.

One trick I have learnt is that after tensioning the belt I start the engine - just to see if it fires - without the cover or the pulley fitted. I just let it fire once and stop it instantly.

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i did the same thing with the false hole on my first attempt. they say the hole is about 10 o'clock but as the false hole is about 9:30 its easy to get wrong. try working back from 12o'clock till the pin slides in.

i ended up taking the rad & grill out so i could look through the pulley & thats how i spotted the correct hole. your pin should go in about 1" when you find the correct hole if i remember correctly. its a lot deeper than the false hole anyway.

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  • 4 weeks later...

Yes, that false hole was the problem. Was doing the job with a mate - he did the injector pump side of things. Once he'd gone and I was well and truly snowed in, I got down to it myself. A 10mm drill bit definitely fits snugly and positively into the injector pump, and slides right through to engage with the hole behind. No play at all. A sure fit.

Once I'd corrected this, engine started first time and sounds lovely.

Now running much cooler than before, doesn't have a problem starting when hot. Just perfect. Well chuffed.

Thanks for all your help, everyone.

Ivan

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As they say in the manual you should put all the pins in before taking the belt off and not turn the engine. I learnt my lesson the first time. The timing only has to be a tiny bit out for the engine not to start.

Yeah, wish I could have put the pins in before taking the belt off, but this belt was shredded!

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On the 'false hole' bit, for once it is an advantage to have the Haynes manual with photos rather than the LR manual with line drawings. The Haynes manual has a nice photo of the position of the injector pulley when the pin is in. They say one picture is worth a thousand words, for that was how I figured out that the pulley didn't look right and so managed to find the right hole, like the famous high-jumper :o

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Finally got round to sorting some pictures of the cam belt saga.

Here's the groove worn in the timing cover by the belt creeping forwards:

post-2520-1173441962_thumb.jpg

post-2520-1173442026_thumb.jpg

And here's the extend of that creep forwards with a new belt after just a dozen turns:

post-2520-1173442048_thumb.jpg

I'm sure I had a picture of the crankshaft sprocket too, but it seems to have vanished. The sprocket only had one lip (on the rear) - the front lip had been prised off by a previous mechanic (?) on the vehicle, thus allowing the cam belt to creep forwards. Clever, eh?

Let that be an end to it (I hope).

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as a wild guess the front crank oil seal probably needed replacing before you got the truck & they tried a puller on the lip of the pulley to remove it. it'd make sense till the lip comes off & you realise its held on with a couple of spot welds (think i remember reading that on here, never looked inside a 300 myself).

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