Replacing the timing belt on a 300Tdi is a bit fiddly. It's a bit like an insurance policy. Most vehicles should have had the kits fitted to prevent premature wear issues so when it got to 6 years since the last belt change, I got the parts ready. I went for a full kit with the belt (
ERR1092), idler (
LHV100150) and tensioner (
LHP100860), as well as a newer forged crankshaft pulley (
LHH100660) instead of the spot welded older type (
ERR4707). There had been some oil coming from the timing case drain hole so I also planned to replace the crankshaft oil seal (
ERR4575) and o-ring (
ERR4710), which I ordered as genuine parts - not wanting to have to go back in and replace everything.
I also bought some tools to help (
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I removed the radiator for better access and visibility, as being my first time I wanted to see what I was doing. I had to tap out the threads in the crankshaft pulley to allow me to fix the holding tool to it. The bolt came undone fine with the breaker bar and piece of metal tube on the end to extend it. The crankshaft pulley (
ERR2220) pulled off nicely and had no scoring on the seal land. I did the time honoured trick of putting the timing case bolts into a piece of cardboard to remember their positions, as they're all different lengths.
The timing case had a bit of gunk in the bottom and some wear on the belt, but it was a long way from snapping. The idler and tension pulleys weren't about to fail, but the bearings were noisy. The timing case cover (
ERR7146) had belt debris across it from wear in the belt, but had no large sections of fluff that used to plague the 300Tdi. With the crankshaft belt pulley removed it showed there was some oil misting from the crankshaft seal. I hammered in a self tapping screw and pulled it out. I had bought a genuine and OEM seal to compare the quality. There was definitely a difference in the material used. The only problem was the genuine seal was damaged! There were a few cuts in the lip. This is where everything got complicated. I had to wait for a replacement to be sent, as I didn't want to fit the OEM seal if genuine was available. It meant I had to clear up everything in the garage, put it in the back of the Defender and push it into the garage, as there was no option of going backwards as my driveway has pretty steep slope and the vehicle was in no state to be started.
When the parts arrived, I got continued on. I removed the timing case outer crankshaft seal (
ERR7143) by heating the aluminium case. I pressed the new inner crankshaft seal in using the old and new pulleys with the crankshaft bolt and washer. Once the pulleys and belt were on I realised the belt was running close to the back of the crankshaft pulley. There was some resistance but I pressed the pulley in a bit more to reveal a gap at the end of the woodruff key and a better central position for the belt to run on.
The new timing case outer seal was troublesome. I heated the timing cover again but I couldn't get the new seal (
ERR7143). In the end I gave up and used the older style rubber seal (
ERR4576). You have to fit it counterintuitively in reverse because this seal is designed to keep water out of the case, instead of oil in. I just remember that the spring always goes towards the liquid to be held back. I fitted the cover back on, loctited the crankshaft pulley bolt and set about
torquing the bolt. I was a bit worried the final 90 degrees would be difficult but with the sturdy breaker bar and pipe extension I just about made it.
In the 5 years since, the belt has had no problems and that's always nice!
