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300Tdi Timing Belt Tension

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I doubt there is a "correct" answer to this, as there are so many answers floating around the Internet, but here goes...

Just did the timing belt on my (Disco) 300Tdi, and the tensioner was set to 22Nm as per the Tech Archive article here.

Having done this, I noticed Rave suggests 14-16Nm using a type of torque wrench that I don't have (see pic), and I see @ 6mins 30secs on a video from Rimmer Bros their mechanic says 12Nm.  Another video suggests 15Nm verbally, but reduces to 11Nm in the text/comments.

Is there a consensus on what I should have done?  That said, I'm probably not going to undo everything now!

Rave.JPG.e24b6586a78ad26c129dc8a6574927ae.JPG

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Why would you take youtube or retailer advice over the workshop manual figures?  Stick to what's in the manual for tensions, preloads and torque figures - LR did extensive calculation and testing to come up with them, youtubers didn't.

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There is conflicting advice from LR hence why people give different values, as it depends on what source they've read.

The TSB that related to the timing belt modification kits in March 1998 says 11Nm, but the 3rd edition Defender 300Tdi workshop manual in May 1999 still says 15Nm for a new belt and 12Nm for used. So who knows. I did 11Nm and it's been fine for 5 years.

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Defender Workshop manual 1999

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There was also a thread on here recently regarding reusing head bolts for the 200tdi. The defender book said one thing the discovery book said another!

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Used 11nm on mine with no ill  effect. I believe the revision of the torque figure is to stop the belt from pulling the injector pump pulley out of line and causing belt wander.

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OK, thanks all.  Since I bought 3 timing cover gaskets, I might as well use the last one (yeah, that's right!) correcting the tension.

 

Can I also suggest the Tech Archive article is updated? 🙂

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12 hours ago, Kurt said:

Used 11nm on mine with no ill  effect. I believe the revision of the torque figure is to stop the belt from pulling the injector pump pulley out of line and causing belt wander.

Makes sense.  The extra tension in a running belt would prevent it skipping teeth at that setting anyway.

I wonder if the lowered tension was as a reflection of the belt alignment issues that plagued 300s, the lower tension being considered a way to mitigate a thinned belt to prevent it from snapping?  Mike at Britannica Restorations (Ontario Youtube series) had issues with one that had the belt kit replacement but still had alignment problems from a warped timing case, all started from the injector pump rear bracket alignment.

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I wish I hadn't seen this. Just done the timing belt on mine but followed the workshop manual...

<_<

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So you used "14 to 16Nm"?  I used 22Nm, which means I know what I'm doing this weekend, again!

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I pretty much do it on what feels right, but I have done it so many times now that can't care to remember.

What is more important though is how tight you do the cap head bolt that holds the slotted roller; I had this come loose on a few occasions and this is potentially lethal for your engine. I replace this bolt for a longer one (next size up), apply loctite and do it up as tight as I dare. 

 

Daan

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