Disco Timing

Discovery Diesel - timing CHAIN? I thought all Disco's except the 3 had a belt! Well known for it's own problems, but timing out, surely not. I seem to recall that you lock the Disco flywheel at TDC, put a pin in the pump, and Bob's your Uncle the timing is correct. I know this comes from the Haynes manual, but surely it can't be that far off.

Cheers! Graham Carter Harare Zimbabwe

whoever fitted the belt has probably not aligned properly or has moved the camshaft gear , or they have moved the injector pump gear .

you need to ask how they changed belt , once they have told you, you will know if they used locking pins on the gears or not .

i would suspect they have moved one of the gears whilst trying to get the belt on , the belt does take some getting on because it is tight to do so and without the locking pins in place it is easy enough to move one of the gears round a tooth .

before taking old belt off you need to lock the flywheel in position at TDC , then lock the injector pump gear using pins located thru holes in gears and holes in the rear timing cover . the crank gear has the keyway pointing directly vertically up and the camshaft gear aligns via marks on the gear and timing cover .

the injector pump has a gear with 3 bolts through it, these bolts are slackened off after the pump shaft has been locked in position which leaves the shaft and injector pump itself locked so it cant move but with the gear being able to be moved slightly left or right in order to align the belt up with the other 2 gears but not to move the injector pump timing/gear .

if it is only slightly out and the engine still runs then get them to remove timing cover , lock injector pump in place using pin and hole , slacken off the pump gear bolts, then realign the camshaft gear marks and flywheel TDC mark and lock pin .

they can take belt off after locking injector pump via lock pin so they can then align the cam gear timing mark and flywheel/ crank at TDC .

once all aligned again reinstall belt and make sure marks are all in line , then tighten pump gear bolts and remove all pins . should be ok after that .

On or around Thu, 24 Nov 2005 19:33:57 +0200, "Graham Carter" enlightened us thusly:

typical of ingorami (the garage) in that they either don't know what they're talking about or assume the punter doesn't

and yes, the "book" timing method is OK but it doesn't work if someone's arsed around with it.

Having said that, I've tweaked ours a bit and it's running the pump a few dergees advanced from the "correct" setting, which improves it. Ideally, apparently, it's worth adjusting the cam timing, but the consequences of getting that wrong are a bit off-putting.

Well explained - I had had a few when I wrote my bit. Good point about the camshaft - I had forgotten you had to take that into account.

Could be that is what is out in Paul's case, but he sounds like he needs to get a mechanic he can trust to check the timing using your correct procedure.

All the best Graham Carter Harare Zimbabwe