300tdi cambelt - some final tips please

I am about to change the cambelt on my defender's 300tdi. I have followed every article on the web that I could find and am pretty confident that there isn't much to it. I am a rather competent DIY mechanic, suffice to say that my 90 has only visited a mechanic twice in 9 years of ownership (once for a clutch which I could not replace due to back pain and once for a cambelt change).

I have purchased the timing pins and crankshaft puller (I did not go the whole hog and purchased the crank holding tool - hence the reason for one of my questions).

A number of nitty gritties are holding me back and would appreciate some advice.

1. I know that a deflection type torque wrench is needed to tension the belt. However, I also know that many of the ones available on the market are not accurate at all and can do more harm than good. Be honest please. How do you guys tension your belts?

2. How do you retighten the crankshaft pulley bolt? I have a 50 litre compressor and impact gun. Do you think it's man enough to tighten the bolt up enough? I was thinking of torquing it up to 80Nm as the manual says, marking the socket, giving it a good solid blast with the pneumatic impact gun and seeing whether it turns a further 90 degrees.

3. Just in case I happen to be stupid enough and mess up the timing, how do i go about rotating the 3 pulleys to re-time the engine once again?

I can't understand why this job scares me so much. I mean i've rebuilt and replaced things like axles single handedly and have experienced no trouble at all.

I used a draper deflection torque wrench when i did my timing belt last week, landrover reduced the torque figure for the belt from 15nm to 11nm. I bought the full timing belt kit off ebay :tensioner+idler, crankshaft drive wheel, dayco belt, timing case gasket.

Don't be worried about it just make sure that the pulleys are in the correct positions and pinned before you release the old tensioner and remove the belt. I found the hardest bit was getting the belt on the pulleys with room for the tensioner.

Remember : once the belt is on and tensioner fixed and tensioned - remove the locking pins and manually rotate the crankshaft 2 revolutions -replace the pins and then slacken off the tensioner and redo the tension to the correct torque.

I did the tensioner 3 times that way

I've done a million and one cambelts I tension just by hand/eye. As you would a fan belt. And not once have a had a problem with whining. I've also only got timing pins for vehicles that have a floating crank pulley. If they're on a keyway like the landy engines a paint dot to a fixed position is more than enough. Or if I'm really trying. A bolt or drill bit instead of the proper pins.. I've never had a cambelt fail or time up wrong In the 8 years I've been doing this job. Don't be scared just go at it with abit of common sence. Oh and as for retightening you bottom pulley. I use a snap-on impact gun. And a touch of lock tight. I can say if you gun is man enough. Because they're all different. Look up the specs of it on the net and work it out.

Thanks for your replies. why is it important to slacken off the tension and redo it?

It is to make sure that you have a constant tension across all of the belt and not just one side
As i said i did the tensioning 3 times

Have a read of this: 300TDI cambelt and Kit - Land Rover Technical Archive - LR4x4 - The Land Rover Forum

Get it done sooner rather than later mate incase the worst happens. I just had to change mine due to this.....






Bent all pushrods and snapped 2 rockers off the shaft.

Another question please gents. I still haven't done it (was too busy over the holidays). I have been told that the belt is a tight fit over the tensioner and idler. Any trick to slip it over?

Planning this job too myself let me know how you get on

I finally found some time to get the job done so I set aside a full day yesterday and got on with it. Job is pretty easy though I didn't find it to be as straight forward as every manual, website, etc made it out to be. All in all, it's a job I would attempt doing again. A few pointers:
1. Undoing the crankshaft bolt. Rather than jamming a breaker bar under the driver's side chassis rail (right hand drive vehicles), I rested it on top of the passenger side chassis rail (I was afraid of damaging the power steering box). 1 flick of the starter got it undone.

2. Removing the radiator is essential. It's so much easier to work with it out of the way.

3. With the fuel injection pump and crankshaft locked, i couldn't get the belt to mesh onto the camshaft gears. Lots of head scratching and bruised fingers later, a mate told me to rotate the camshaft ever so slightly and i did. Fitting the belt was then a doddle.

4. Don't fit the tensioner bolt until the belt is snuggly fitted over the tensioner. Once the belt is in place, ease the tensioner into position and screw the bolt in.

This is where my problems started. I tensioned the belt, tightened the 3 bolts on the fuel pump pulley, removed the timing pins and rotated the crankshaft twice. Inserted the timing pin in the fuel injection pump pulley slot, crawled under the vehicle and to my my chagrin, found the slot about half a tooth out. Removed the belt, lined up the crankshaft, re-locked it, re-fitted the belt, tensioned, etc etc etc, rotated the crankshaft twice again, re-checked, same again. To cut a long story short, on the 4th or 5th attempt, marks lined up. Rotated twice, all ok, rotated another 2 times, dang, it was out by half a tooth again. Decided to start the engine. It spun round on the starter a couple of times more than usual and started normally. sounded ok and didn't smoke at all. I called my mate again (who has more experience than I do) and he told me to take it for a spin and see how it behaves. So I re-assembled everything and took it for a quick spin. Everything seemed to be in order. This morning it started right away as it always did. I am still a bit sceptical about how things turned out and I won't put my mind at rest until I've covered at least a couple of hundred miles.

Dont worry about it, if it goes ok then its all right.

If you were down on power or smoking then worry, take a minute to check pump timing through the inspection cover if you want to be sure, just check it with flywheel mark and adjust as nesessary.

thanks buddy. No there's no noticeable difference in smoke (i'd dare to say that it's actually smoking a tad less) and power delivery is practically the same. It feels a bit sharper but I think that's due to the fact that I cleaned the intercooler.

You should always lock the flywheel first then lock the injection pump - if you find that you can't get the pin into the injection pump - loosen the 3 bolts on the pump pulley and turn the centre bolt slightly (22mm iirc) to line up the hole so that the pin is a sliding fit. NOT forgetting to retighten the 3 bolts!!

That way you know the flywheel is locked at TDC and can check that the camshaft is in the correct position with the timing marks ALL without removing/replacing the belt

The timing is then set - spot on

If you aren't sure that your timing is correct:

Remove inspection plate from timing cover
Lock flywheel at TDC with the correct locking pin
Injection pump timing pin should be a sliding fit through the inspection hole in the timing cover
(the only thing you can't check with the timing cover on is the camshaft timing marks - which should line up perfectly when the flywheel and injection pump are locked - if you have put the belt on correctly)

Some great info there. Thanks a lot.

Did my mates the other day, has to be the easyest timing belt I've ever done, (200 tdi)

His is a challenge truck with the engine moved back so I could get right in, gone do mine next 300 tdi but ill just take my rad out to make it easyer

warrior said:

Did my mates the other day, has to be the easyest timing belt I've ever done, (200 tdi)

His is a challenge truck with the engine moved back so I could get right in, gone do mine next 300 tdi but ill just take my rad out to make it easyer

Click to expand...

You can flip the rad on top of the engine while you do the job, just top hose off.... and it is very easy on 300 as no water pump bolts to break off

landowner said:

You can flip the rad on top of the engine while you do the job, just top hose off.... and it is very easy on 300 as no water pump bolts to break off

Click to expand...

good to hear, just got all the bits to do mine

Hi I have brought the belt but it didnt come with any other bits.

Would this be fine to fit?

Land Rover Defender / Discovery / Range Rover 300 Tdi Timing / Cambelt kit | eBay


Thanks

you might want to fit a better make of idler and tensioner ,but other bits are fine

can you fire me a name of a brand to order? gonna attempt this at the end of the month

Cheers