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Discussion Starter #1
I am having a real problem with my cam belt tensioner, have had a couple of friends look at it, and still not been able to come up with any ideas.

I have set engine, cam and fuel pump to markings, and locked it in place.

Removed cam belt, put new one on, and have then been stuck trying to fit the cambelt tensioner.

The tensioner has a 13mm headed bolt in the middle and a 10mm headed locator bolt that goes through the slot on the back plate of the tensioner. I have put the tensioner on, located both the 10mm and 13mm bolts, done the 13mm up to various tensions - from nipped up to fingertight. Put the big 27mm spanner on the big nut in the middle of tensioner and am buggered if i can turn it clockwise (as per manual) to get the two location points to match up. The 27mm nut turns, the tensioner moves on an eccentric cycle the 10mm head bolt sliding up and down the slot. (is it supposed to do this? or should it lock into a postion to begin with) The arrow shaped point on the rear of the tensioner though just doesnt move though.

I have tried the old tensioner and the new one, but it has the same effect.

Can anyone suggest anything I am doing wrong? ...or suggest a VW mechanic in Essex, mobile or otherwise (it is in a dry, lit workshop at the moment) that maybe sympathetic to help someone who has taken something apart but cant put it back together again. A:

thanks
 

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hi Nick

have you loosened the the cam pulley nut and knocked it off its taper so it can spin freely?
not sure if that's the problem but it could be the reason (if the cam puley is somehow holding it under tension and not allowing it to go where it needs to be)
 

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For a start that 10mm bolt you mention is not original,there should be a peg that the tensioner slots onto with the elongated hole.
Cam sprocket should be free from the taper and the bolt should be finger tight so the sproket can turn when the tension is applied.You have to apply quite a bit of leverage on the tensioner to get the pointer to move downwards towards the marker and the 13mm headed bolt should not be tight whilst doing this.
 

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Discussion Starter #4
For a start that 10mm bolt you mention is not original,there should be a peg that the tensioner slots onto with the elongated hole.
Cam sprocket should be free from the taper and the bolt should be finger tight so the sproket can turn when the tension is applied.You have to apply quite a bit of leverage on the tensioner to get the pointer to move downwards towards the marker and the 13mm headed bolt should not be tight whilst doing this.
Aggies, I would be surprised if the 10mm bolt is not original, it is the same as the other bolts that hold the cowelling on. I cant see how the tensioner is supposed to work, the 27mm bolt just seems to turn independant to the back plate with the pointer on????

thanks
 

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Discussion Starter #5
Aggies, I would be surprised if the 10mm bolt is not original, it is the same as the other bolts that hold the cowelling on. I cant see how the tensioner is supposed to work, the 27mm bolt just seems to turn independant to the back plate with the pointer on????

thanks
....just had a thought, wonder if i have been trying to put the elongated slot in the wrong place. The marker that show the correct tension is about 12 o'clock, and really difficult to see, does that sound right?
 

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Well be prepared to be suprised and believe that the 10mm bolt is not original because that is fact,i have replaced the belts and waterpump today on an AJT motor and have been doing this job for years,on average 3-4 a month and i have never seen a 10mm bolt that goes through the eccentric hole in the tensioner.My guess is that sometime in the past the peg that should be there for the tensioner to locate on has been broken off by some cowboy mehanic and he has used the said 10mm bolt as a substitute.
You are doing something wrong for the tension spring not to be doing what it should,is the 13mm bolt loose/finger tight when applying tension? When you turn the tensioner with the large 27mm nut is it rotating 360 degrees without tensioning? Have you checked the length of the old belt against the new belt?
 

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For a start that 10mm bolt you mention is not original,there should be a peg that the tensioner slots onto with the elongated hole.
Cam sprocket should be free from the taper and the bolt should be finger tight so the sproket can turn when the tension is applied.You have to apply quite a bit of leverage on the tensioner to get the pointer to move downwards towards the marker and the 13mm headed bolt should not be tight whilst doing this.
Aggie is right there is only 13mm bolt that holds it on and the tensioner backing should slot over a peg :confused: also make sure your turning the 27mm adjuster the right way ...

You could take a pic which might help..
 

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My engine is ACV which I think uses the same tensioner as the AJT. I think the problem in this discussion is one of terminology.
A bolt size is determined by the shank size not the hex AF dimension. The spare I have taken out of my engine actually measures 8mm which would be 13mm AF. I don't know where the 27mm comes from, mine is 32mm.
It seems to me that the backing hasn't been installed properly over the peg as Wagenworx has said.
 

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Discussion Starter #10
Update, and appear to have solved it!

......had a couple of PM's back and forth with Aggie, around the kit being right one, the tensioners and belt being the same size etc as the old one, and also the direction that the backing plate tensioner tab should be pointing (3 pm) then realised that m y backing plate tensioner tab was pointing wrongly at the 12 o’clock .

Had a look this afternoon, took off the tensioner, fitted it with the backing plate tab at 1/4 past, and the elongated hole fitted nicely over the newly discovered peg. Wound the tensioner round and the points line up.

In my defence I am sure that it was fitted wrong when I took it apart. The tensioner tightened the belt the way it was fitted but there was little adjustment and no benefit of a spring. When I stripped it out I noticed how tight the old belt was (almost impossible to get off, even when the tensioner was wound back. But when tensioner fitted correctly the belt fitted on nicely. It also looked, according to some wear and dirt markings on the engine plates that the adjuster had been in this position for some time and hadn’t been anywhere near the peg. I also remember peering up at the 12’oclock position and seeing how far out the pointers were as I took off the cover.

Oddly, the van (new to me) has a full VW service history - unless someone else has had it apart.

Anyway, thanks to all advice, in particular to Aggie.

Cheers Aggie
 

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Good work happy you got there in the end,
Happy to help when and where i can,thanks for the feedback T:
 

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when i read posts like this i remember why i keep to my mechanical limits!:eek:
fair play to those that have a go.....but people like aggie will get my business...rather than the scrapman when i totally it up!:D
 

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Discussion Starter #16
When i did mine, i took a photo of it all before removing belts etc, so i had something to refer to when putting it all back together again.
Am adamant that I did put it back where I found it, think it will be one of those things i will never know for sure! What i do know is that who ever did it before lost a load of bolts, cos it is a right old assortment!!!!
 
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