VW camblet, torque settings

PaulGooch

PaulGooch

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A friend has posted on another forum about his recent cam belt change on a VW based Cummins engine, the 5 pot 2.5lt motor.

A Cummins engineer turned up to do the job, who had never done one of these engines before. Back in Sept, he did a course on the VW engines, as Cummins were to take over VW marine servicing, he did a single bench change of the belt on each of 5 VW engines, this one included. Although this was his first time fitting a belt to this engine, i understand he is an experienced "fitter".

The main point of this post though is the torque setting he used. The specified settings for the camshaft pulley is 120nm and the adjusters are 20nm.

He didn't feel these were enough, and did the camshaft pulley at 400nm (yes, 400nm) and the adjusters at 40nm.

Comments please ?
 
I would suggest that either the specified settings are wrong (maybe from a different engine?) or the engineer did not really tighten the camshaft pulley with 400nm.
If you would tighten a bolt with a (correct) setting of 120nm to 400nm it would defibately break / shear / the thread would come off.
 
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400Nm is ridiculously tight. Imagine applying a force of 400N ( thats about 90lbs) on the end of a 1 metre tommy bar. I cannot believe anyone would do that

20Nm for the adjusters sounds reasonable but it depends on the size of the bolt

120Nm sounds quite a bit for the pulley (presummably you mean sprocket) but if that's what's specified that's what it should be.

120 Nm = 89 lbs ft in old money and 20 Nm = 15lbs ft
 
VicS said:
400Nm is ridiculously tight. Imagine applying a force of 400N ( thats about 90lbs) on the end of a 1 metre tommy bar. I cannot believe anyone would do that

20Nm for the adjusters sounds reasonable but it depends on the size of the bolt

120Nm sounds quite a bit for the pulley (presummably you mean sprocket) but if that's what's specified that's what it should be.

120 Nm = 89 lbs ft in old money and 20 Nm = 15lbs ft
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Can't swear to it, but i suspect the adjusters are M8.

Yes, pulley/sprocket (cam, not crank). I agree 120nm should be plenty, certainly more than many on engines of that size.
 
The story has now changed a wee bit lol

What he did was tightened it to 120, then put the wrench back on and gave it a couple of good pulls...

He had both feet against the breaker bar and was pushing with all his might to get it undone...

I remarked .**** me thats in there.. He said, 120nm my rrrr's.. more like 400 for that mother
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Still seems an "unusual" method of reassembly.
 
To compare, the large screw that holds on the lower pulley / vibration damper to the end of the crankshaft on a KAD32 is torqued to 180Nm.

400Nm = lots :eek:
 
PaulGooch said:
The story has now changed a wee bit lol



Still seems an "unusual" method of reassembly.
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Strikes me that this gobbly clown has no place in a customer facing role.

I would be interested to know why cam belt is being changed? In automotive applications it is somthing like 80,000 miles of five years whatever comes first.

Well known for years that people in the know the five pot VW can suffer misfire problems if crank pully capscrew backs off, and keyway beats in and slackness causes misfire. Experienced VW service dealers take the capscrew to correct torque and then give give it a little more ow's yer farther for good measure not ragging it to death! Our man may have been taking matters far too literally, and he would be unlikely to have torque wrench of this range on the van, certainly had no place doing prima donna bit in front of the customer, and just keep his unnoficial 'fix' to himself.

Think I would instruct the service controller to record an verbal warning and leave the prima donna in no doubt that he is a marked man!
 
Latestarter1 said:
Strikes me that this gobbly clown has no place in a customer facing role.

I would be interested to know why cam belt is being changed? In automotive applications it is somthing like 80,000 miles of five years whatever comes first.

Well known for years that people in the know the five pot VW can suffer misfire problems if crank pully capscrew backs off, and keyway beats in and slackness causes misfire. Experienced VW service dealers take the capscrew to correct torque and then give give it a little more ow's yer farther for good measure not ragging it to death! Our man may have been taking matters far too literally, and he would be unlikely to have torque wrench of this range on the van, certainly had no place doing prima donna bit in front of the customer, and just keep his unnoficial 'fix' to himself.

Think I would instruct the service controller to record an verbal warning and leave the prima donna in no doubt that he is a marked man!
Click to expand...

Not sure how old the boat is.

The bolt that was overtightened the most was the cam pulley bolt, not the crank. Even worse ?
 
If the bolt really has been tightened to 400Nm ... I'd not only worry about the bolt but the threads in the camshaft!
 
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