Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: gbh on 28 May 2016, 20:19:38

Title: Cambelt HELP!!
Post by: gbh on 28 May 2016, 20:19:38
Help is the word i would use,i've been at it all day on my first change. Were am i at,well followed instructions from dvd and got to first rotation,one thing of note no timing markings on GM belt. So after one rotation timing markings were about 1cm out to the left of center after several turns and adjustments i'm now 2cm out to the left of center. Question of course is how to correct?
Title: Re: Cambelt HELP!!
Post by: Nick W on 28 May 2016, 20:36:23
Many belts don't have marks. The ones that do won't line up once you've turned the engine through. Ignore them.


What you must pay attention to is the markings on the cam pulleys and your locking kit.


You must ensure that you have the eccentrics placed so that the belt is tight when you remove the locks. This gives you enough adjustment to accurately time both banks. If yours have moved as much as you say, then you probably have to time your engine from scratch.
Title: Re: Cambelt HELP!!
Post by: gbh on 28 May 2016, 20:42:23
The tensioner went slack on 1st rotation i think that's were the problem started. Where and how to start from scratch?
Title: Re: Cambelt HELP!!
Post by: gbh on 28 May 2016, 20:43:16
Car is a 2.6 v6 Y reg
Title: Re: Cambelt HELP!!
Post by: Nick W on 28 May 2016, 21:06:13
The tensioner went slack on 1st rotation i think that's were the problem started. Where and how to start from scratch?


I believe it's covered in the DVD. But, you carefully turn what you have through until the mark on the crank pulley(need a mirror and torch to see it clearly, and I like a paint mark on both too) is about 60 degrees before TDC. Then you can remove the belt, and use all 3 hands to align the cams and install the locks. Next you rotate the crank with its lock onto the waterpump. Now you fit the belt, ensuring that you have the eccentrics tight against it, and time as the DVD shows.


A 2.6 is easier as you don't have an adjuster on the long belt run.
Title: Re: Cambelt HELP!!
Post by: gbh on 28 May 2016, 22:39:22
3 Hands??
Title: Re: Cambelt HELP!!
Post by: Nick W on 28 May 2016, 22:54:16
3 Hands??


You need to hold both cams in a specific place, and insert the lock. That makes 3.


Smartarse way of saying it's awkward to do.
Title: Re: Cambelt HELP!!
Post by: gbh on 29 May 2016, 05:33:48
Is there any reason why as all 4 cams are the same 2cm away to the left that if i wedged a screwdriver between or cam locks between the cams then remove belt,then move cams to the right 2cm from left to right then put lock back in and retime If crank is locked TDC to begin with?
Title: Re: Cambelt HELP!!
Post by: gbh on 29 May 2016, 05:45:44
Getting a bit confused here i think, so with the belt on in its current set up turn the crank until its 60 degrees before TDC which is where on a clock face? Where does the crank mark need to be on a clock face and do i lock it or will it just stop there?
Title: Re: Cambelt HELP!!
Post by: Andy H on 29 May 2016, 07:55:00
Is there any reason why as all 4 cams are the same 2cm away to the left that if i wedged a screwdriver between or cam locks between the cams then remove belt,then move cams to the right 2cm from left to right then put lock back in and retime If crank is locked TDC to begin with?
:-X
Title: Re: Cambelt HELP!!
Post by: Andy H on 29 May 2016, 07:57:31
Getting a bit confused here i think, so with the belt on in its current set up turn the crank until its 60 degrees before TDC which is where on a clock face? Where does the crank mark need to be on a clock face and do i lock it or will it just stop there?
About 10 O'Clock. The crank won't go anywhere but the cams have to be locked because the pressure from valve springs will turn the cams with some force.
Title: Re: Cambelt HELP!!
Post by: YZ250 on 29 May 2016, 09:03:11
I'm assuming that you have the full locking kit here. The quote below may help you but just ignore the bits regarding the white lines as you say yours is an unmarked belt.  :y The principle is the same.  :y
As said, if you are out of position, put the crank to a safe position (search forum if unsure), remove the belt and start again. Check, re-check and treble check before putting it back together and ask again if you are unsure and we will try to guide you through it.  :y

On the 2.6/3.2 I line up the white line with the crank pulley and then use the wedge, undo the crank locking tool from the water pump and back the crank off a tooth or so, making sure that the belt goes with the crank, so that you can feed the belt ANTI-CLOCKWISE around the lower idler and up to cam 4 and 3. When the lines match the locked cam notches on 3 and 4, rotate the crank back to its locked position on the water pump. Feed the belt under the upper idler/adjuster and up over cams 2 and 1, then around the tensioner. This to me is the only way to keep the tension between cams 3 and 4 and the crank, as there is no other adjustment at this end.  :y This way you have tension between cams 3, 4 and the crank sorted and the adjuster only has to take the slack from cams 1 and 2.

Hope that makes sense.

The last bit of the thread below may be of some use but would have been better if I'd taken the photos with the checking tool in place.  ::)

http://www.omegaowners.com/forum/index.php?topic=134336.0
Title: Re: Cambelt HELP!!
Post by: gbh on 29 May 2016, 09:43:52
Yes i have the locking kit,so in essence with belt on at the moment rotate the crank to a safe position(unsure where that is) remove the belt then rotate each cam to its timing mark then apply locks then rotate crank to its timing mark(unsure where that is) and apply lock then belt on and retime as per dvd. Does that sound about right?
Title: Re: Cambelt HELP!!
Post by: YZ250 on 29 May 2016, 10:42:23
Yes i have the locking kit,so in essence with belt on at the moment rotate the crank to a safe position(unsure where that is) remove the belt then rotate each cam to its timing mark then apply locks then rotate crank to its timing mark(unsure where that is) and apply lock then belt on and retime as per dvd. Does that sound about right?

You'll need a mirror and a torch.  :y Is this the 2.6 in your profile? If it is, I found it easier to use the DVD as a strip down guide but due to having no lower adjuster you will need to feed the belt on anti-clockwise. If you have already rotated the crank with no resistance then I would suggest setting the crank, using a mirror and a torch, so that the crank pulley notch lines up with the casing notch, fit the crank lock and set against the water pump, remove the belt and set the cams correctly. Fit the belt in manner previously suggested.  :y

(http://i894.photobucket.com/albums/ac142/Alan-Hearn/Random%20Pics/image_zpsdndclumi.jpeg) (http://s894.photobucket.com/user/Alan-Hearn/media/Random%20Pics/image_zpsdndclumi.jpeg.html)
Title: Re: Cambelt HELP!!
Post by: Andy H on 29 May 2016, 10:54:19
Getting a bit confused here i think, so with the belt on in its current set up turn the crank until its 60 degrees before TDC which is where on a clock face? Where does the crank mark need to be on a clock face and do i lock it or will it just stop there?
About 10 O'Clock. The crank won't go anywhere but the cams have to be locked because the pressure from valve springs will turn the cams with some force.
Hmm - I should have read your words more carefully. I think I had to use a mirror on a stick to see the timing mark on the crank so I guess that must be underneath when the crank is at TDC  :-\
Title: Re: Cambelt HELP!!
Post by: gbh on 29 May 2016, 11:43:14
The sun is still out so today i'll be outside trying my best,so with that in mind and not wanting to damage anything.Firstly i should rotate crank with belt still on until the bottom timing mark lines up then apply lock to water pump then its safe to remove the belt without cam locks as they won't fit anyway.Then manually rotate cams into timing position or 2cm to right in my case then apply cam locks fit belt etc. When i remove the belt are the cams going to move and if so do i continue clockwise if they go past the timing mark?
Title: Re: Cambelt HELP!!
Post by: gbh on 29 May 2016, 11:49:20
One other thing i put the belt on as per the dvd and the bottom adjuster looks the same as in the dvd and i set it to 3 o clock. How do i know if its adjustable or not ? My cam kit is GM9201887 for a 2.6 v6 est 2001.
Title: Re: Cambelt HELP!!
Post by: terry paget on 29 May 2016, 11:52:20
Getting a bit confused here i think, so with the belt on in its current set up turn the crank until its 60 degrees before TDC which is where on a clock face? Where does the crank mark need to be on a clock face and do i lock it or will it just stop there?
About 10 O'Clock. The crank won't go anywhere but the cams have to be locked because the pressure from valve springs will turn the cams with some force.
Hmm - I should have read your words more carefully. I think I had to use a mirror on a stick to see the timing mark on the crank so I guess that must be underneath when the crank is at TDC  :-\
Standing in my pit looking at the crank pulley at TDC it is at 6 o'clock.I turn it anticlockwise to 4 o'clock. This is about 60 degrees BTDC and a point where all pistons are out of harm's way. This allows you to turn all the camshafts without fear of damage to valves.
I appreciate looking from above with mirror and torch things get confusing.
Title: Re: Cambelt HELP!!
Post by: gbh on 29 May 2016, 12:04:10
As the belt is ON at the moment should i rotate clockwise until i get to 4 o clock
Title: Re: Cambelt HELP!!
Post by: Nick W on 29 May 2016, 12:26:01
The sun is still out so today i'll be outside trying my best,so with that in mind and not wanting to damage anything.Firstly i should rotate crank with belt still on until the bottom timing mark lines up then apply lock to water pump then its safe to remove the belt without cam locks as they won't fit anyway.Then manually rotate cams into timing position or 2cm to right in my case then apply cam locks fit belt etc. When i remove the belt are the cams going to move and if so do i continue clockwise if they go past the timing mark?


No, you need the crank to be at 60degrees before TDC so you can safely turn the cams individually. This means having the crank lock(if fitted) at about 10 o'clock, and the timing mark on the crank about 4 o'clock.


Once you have the cams aligned with the gauge you insert their locks, which is where having a third hand is useful.


The next step is to rotate the crank 60degrees to TDC so that the crank lock engages with the water pump.


Then you fit the cambelt: secure it around the crank pulley using the wedge in the kit; working anti-clockwise you run it past the lower roller pulley; over the nearside cam pulleys(clothes pegs will hold it place if you're nervous); under the centre adjuster - having this free to adjust is helpful; on to cams 1 and 2; then back down past the tensioner.


Then, you adjust the centre adjuster so that the belt is tight between the banks and tighten its Torx bolt. Check that all of the pulleys etc are tight, and remove the locks.


Now you get to rotate the crank 2 full turns, refit the crank lock and use the gauge to see how much you need to adjust everything. As a 2.6 should have a plain pulley rather than a lower adjuster, cams 3 and 4 should still line up. The centre adjuster is then used to bring cams 1and2 into alignment - you don't need to turn it much to gain a noticable adjustment. Tighten the adjuster bolts, remove the locks, and turn it through 2 full turns and check again. This can take 2 or 3 goes to get right; it's the important part of the job. Once all 4 cams lineup everytime, you set the tensioner as shown in the DVD, check again, fit the belt cover and go for a lie down.






Title: Re: Cambelt HELP!!
Post by: Nick W on 29 May 2016, 12:26:38
As the belt is ON at the moment should i rotate clockwise until i get to 4 o clock




ALWAYS!
Title: Re: Cambelt HELP!!
Post by: Andy H on 29 May 2016, 13:49:49
If the cambelt is more than 2 teeth out then turning the engine over is likely to result in pistons bending valves.

It is probable that your belt wasn't fully engaged in the bottom pulley so when you started turning the crank the teeth on the belt engaged with the teeth on the pulley causing the loss of tension. If this is what happened then your belt will now be one tooth out (but safe to turn over).

Before you do anything else, if you intend turning the engine over, make sure that there is enough tension on the belt to make sure it doesn't skip any teeth.

If the crank is currently at TDC then you don't absolutely need to turn it over. You could wind it back to 60deg BTDC (where it is safe) then pull the belt off and wrestle the cams into their correct position and put the camlocks in.
Title: Re: Cambelt HELP!!
Post by: gbh on 29 May 2016, 15:19:24
Well the belt is back on as per instructions,i can confirm that the lower roller is adjustable and there is a bit of slack on that side when compared to tensioned side but putting the belt on anti clockwise was a lot easier. I've set top roller to 12 o clock and lower to 3 o clock if the lower one is set differently it takes up the slack.Any advice before the first revolution?
Title: Re: Cambelt HELP!!
Post by: Andy H on 29 May 2016, 15:34:59
The adjustable rollers need to be fitted so that turning them anti-clockwise tightens the belt - if the tension of the belt causes them to move then they will turn clockwise and tend to tighten the centre retaining bolt.

If they are fitted the other way then there is a chance that belt tension could rotate them ant-clockwise and loosen the centre retaining bolt.
Title: Re: Cambelt HELP!!
Post by: terry paget on 29 May 2016, 16:41:58
The adjustable rollers need to be fitted so that turning them anti-clockwise tightens the belt - if the tension of the belt causes them to move then they will turn clockwise and tend to tighten the centre retaining bolt.

If they are fitted the other way then there is a chance that belt tension could rotate them ant-clockwise and loosen the centre retaining bolt.
Very good point, Andy, which had not occured to me. I recently realised that the 30mm cranked box spanner discussed recently was for this adjustment. I have not got one, and made do with an open ended spanner, not an elegant solution. I live and learn.
Title: Re: Cambelt HELP!!
Post by: Nick W on 29 May 2016, 19:48:58
I recently realised that the 30mm cranked box spanner discussed recently was for this adjustment. I have not got one, and made do with an open ended spanner, not an elegant solution. I live and learn.


I did that as my used locking kit is the cheaper Sealey set without the spanner. Buying one separately is seriously costly. Trying to do a delicate adjustment with a bloody great 30mm spanner is definitely not elegant. Or easy.


I repurposed a scrap 30mm socket to make this:


(https://www.dropbox.com/s/d06kigcq0h68pex/CamAdjusterSpanner.jpg?dl=1)


which cost nothing, and makes the job easy.


Hopefully the OP is now relaxing with a well earned drink and a running car :y
Title: Re: Cambelt HELP!!
Post by: gbh on 29 May 2016, 21:07:26
Things are beginning to look a bit brighter thanks to u all,after 2 rotations it appears to be timed but i'll do it twice more tomorrow to be sure.The dvd is misleading that's for sure and probably needs revision on my very limited experience.Putting the belt on anti clockwise was a much better fit from the start, anyway weather permitting double check timing then put it all back together tomorrow and hope it all works properly.Many many thanks once again Glenn
Title: Re: Cambelt HELP!!
Post by: terry paget on 29 May 2016, 21:22:45
I recently realised that the 30mm cranked box spanner discussed recently was for this adjustment. I have not got one, and made do with an open ended spanner, not an elegant solution. I live and learn.


I did that as my used locking kit is the cheaper Sealey set without the spanner. Buying one separately is seriously costly. Trying to do a delicate adjustment with a bloody great 30mm spanner is definitely not elegant. Or easy.


I repurposed a scrap 30mm socket to make this:


(https://www.dropbox.com/s/d06kigcq0h68pex/CamAdjusterSpanner.jpg?dl=1)


which cost nothing, and makes the job easy.


Hopefully the OP is now relaxing with a well earned drink and a running car :y
I find that my 30mm open ended spanner has a cranked ring on the other end, which just engages with the tensioner pulley end. I shall try that next belt change, unless something better comes along. Pic follows.
(https://www.dropbox.com/s/k9u56iscqugfmg0/CAMbeltPULLEYspanner.jpg?dl=1)
Title: Re: Cambelt HELP!!
Post by: Andy B on 29 May 2016, 22:26:39
I got my cranked 30mm ring spanner from stores  ::)
Title: Re: Cambelt HELP!!
Post by: 05omegav6 on 29 May 2016, 23:06:46
Getting a bit confused here i think, so with the belt on in its current set up turn the crank until its 60 degrees before TDC which is where on a clock face? Where does the crank mark need to be on a clock face and do i lock it or will it just stop there?
10 o clock as you look at it :y
Title: Re: Cambelt HELP!!
Post by: Andy H on 30 May 2016, 09:22:20
Getting a bit confused here i think, so with the belt on in its current set up turn the crank until its 60 degrees before TDC which is where on a clock face? Where does the crank mark need to be on a clock face and do i lock it or will it just stop there?
10 o clock as you look at it :y
That was my first answer because that is correct if you are looking at the timing tool- BUT the timing mark is on the bottom of the crank pulley so 4 O'Clock is the winning answer.
Title: Re: Cambelt HELP!!
Post by: terry paget on 30 May 2016, 11:43:42
As the belt is ON at the moment should i rotate clockwise until i get to 4 o clock




ALWAYS!
Why not anticlockwise, through 60 degrees rather than 300 degrees? Come to that, would it not be as safe 60 degrees after TDC as before it?
Title: Re: Cambelt HELP!!
Post by: Nick W on 30 May 2016, 13:47:14
As the belt is ON at the moment should i rotate clockwise until i get to 4 o clock
Hi



ALWAYS!
Why not anticlockwise, through 60 degrees rather than 300 degrees? Come to that, would it not be as safe 60 degrees after TDC as before it?

It's bad practice to rotate it anti-clockwise because the tensioners don't work that way, and you could loosen the crank bolt. Of course both those points are moot in this case, you're never going to accidentally loosen the bolt, but why take the chance?
Title: Re: Cambelt HELP!!
Post by: gbh on 30 May 2016, 16:07:57
All stop again which is annoying,came to fitting the pulleys crank and a/c torqued to 20nm after searching on here then the water pump which seems to be somewhere between 8-12nm anyway at 8nm 2 of them didn't feel that great like they might sheer so i removed and will replace all 3 i think maybe clean the threads as well.Best place for bolts and do you use Loctite? Then which torque? Unfortunately on the dvd he never tightens the bolts only by hand maybe he forgot!!!
Title: Re: Cambelt HELP!!
Post by: Andy H on 30 May 2016, 16:20:46
All stop again which is annoying,came to fitting the pulleys crank and a/c torqued to 20nm after searching on here then the water pump which seems to be somewhere between 8-12nm anyway at 8nm 2 of them didn't feel that great like they might sheer so i removed and will replace all 3 i think maybe clean the threads as well.Best place for bolts and do you use Loctite? Then which torque? Unfortunately on the dvd he never tightens the bolts only by hand maybe he forgot!!!
According to the Haynes book the bolts should be 'angle tightened' and used only once. I haven't angle tightened or replaced mine - so far I have just tightened them to 8Nm with a dab of Loctite for luck.

You are right to be cautious, Kevin Wood recently had the water pump pulley make a bid for freedom on his car (I assume he was driving his Omega and not his LSIS)
Title: Re: Cambelt HELP!!
Post by: gbh on 30 May 2016, 16:26:12
Which Loctite?
Title: Re: Cambelt HELP!!
Post by: terry paget on 30 May 2016, 16:44:16
As the belt is ON at the moment should i rotate clockwise until i get to 4 o clock
Hi



ALWAYS!
Why not anticlockwise, through 60 degrees rather than 300 degrees? Come to that, would it not be as safe 60 degrees after TDC as before it?

It's bad practice to rotate it anti-clockwise because the tensioners don't work that way, and you could loosen the crank bolt. Of course both those points are moot in this case, you're never going to accidentally loosen the bolt, but why take the chance?
Fair comment. I first did this job on a clattering engine (2 teeth out) and wanted to turn it the minimum angle. I wondered if there were any cams on the engine with steep back slopes that would resent/resist being turned the wrong way. I have two on print presses.
Title: Re: Cambelt HELP!!
Post by: Andy B on 30 May 2016, 16:53:33
Which Loctite?

Take your pick  https://www.google.co.uk/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=loctite%20threadlocker :y
there are different grades for different applications, but in this case, any one of them will be good enough
Title: Re: Cambelt HELP!!
Post by: terry paget on 30 May 2016, 17:12:45
All stop again which is annoying,came to fitting the pulleys crank and a/c torqued to 20nm after searching on here then the water pump which seems to be somewhere between 8-12nm anyway at 8nm 2 of them didn't feel that great like they might sheer so i removed and will replace all 3 i think maybe clean the threads as well.Best place for bolts and do you use Loctite? Then which torque? Unfortunately on the dvd he never tightens the bolts only by hand maybe he forgot!!!
According to the Haynes book the bolts should be 'angle tightened' and used only once. I haven't angle tightened or replaced mine - so far I have just tightened them to 8Nm with a dab of Loctite for luck.

You are right to be cautious, Kevin Wood recently had the water pump pulley make a bid for freedom on his car (I assume he was driving his Omega and not his LSIS)
I have found the Haynes instruction, as you say 8Nm then tighten 30 degess/30 degrees. All I have ever done is do them up finger tight, put on the belt, then nipped them up as I think fit, knowing the belt will slip if I get carried away.
Title: Re: Cambelt HELP!!
Post by: gbh on 31 May 2016, 09:08:03
I just contacted Vauxhall who say there are 2 types only difference is length 13mm and 15mm both about a £1 each but the 15mm are  minimum order of 10.Mine i would say are 15mm but 13mm should be ok with Loctite what do you think?
Title: Re: Cambelt HELP!!
Post by: Kevin Wood on 31 May 2016, 09:47:04
Loctite is essential on the water pump pully bolts as they are so physically small that they can't take a lot of torque. They are probably worth  replacing every couple of belt changes, TBH. Mine had been off or a running repair shortly after the last cam belt change and probably didn't get replaced with enough, or any, Loctite.

2 of them had come undone and dropped out. The third one sheared during a spirited climb up a steep dual carriageway. Luckily, I didn't lose the pulley itself and nothing went into the cam belt. The water pump immediately blew its' seal, probably due to instant boiling of coolant in the block as the pressure and flow dropped (like I said, I was driving "spiritedly"). ::)
Title: Re: Cambelt HELP!!
Post by: Nick W on 31 May 2016, 10:06:02
I just contacted Vauxhall who say there are 2 types only difference is length 13mm and 15mm both about a £1 each but the 15mm are  minimum order of 10.Mine i would say are 15mm but 13mm should be ok with Loctite what do you think?

Use the longer bolts with a washer.
But these are standard M6 bolts that cost pennies. You could buy a box of several hundred and have enough change from that tenner for lunch. Buying them from Vauxhall is stupid.
Title: Re: Cambelt HELP!!
Post by: terry paget on 31 May 2016, 15:19:00
Loctite is essential on the water pump pully bolts as they are so physically small that they can't take a lot of torque. They are probably worth  replacing every couple of belt changes, TBH. Mine had been off or a running repair shortly after the last cam belt change and probably didn't get replaced with enough, or any, Loctite.

2 of them had come undone and dropped out. The third one sheared during a spirited climb up a steep dual carriageway. Luckily, I didn't lose the pulley itself and nothing went into the cam belt. The water pump immediately blew its' seal, probably due to instant boiling of coolant in the block as the pressure and flow dropped (like I said, I was driving "spiritedly"). ::)
Thank you gentlemen. Next time I change a cam belt I shall change my procedure in several ways. I see Haynes recommends new bolts and angle tightening for the  power steering pulley too, but not for the crankshaft pulley. I should be nervous of angle tightening 30:30 those small water pump pulley bolts. I was taught that angle tightened bolts should never be re-usued, as they have been stretched on first use, but on this forum this rule is widely ignored.
 
Title: Re: Cambelt HELP!!
Post by: Nick W on 31 May 2016, 16:55:24
Thank you gentlemen. Next time I change a cam belt I shall change my procedure in several ways. I see Haynes recommends new bolts and angle tightening for the  power steering pulley too, but not for the crankshaft pulley. I should be nervous of angle tightening 30:30 those small water pump pulley bolts. I was taught that angle tightened bolts should never be re-usued, as they have been stretched on first use, but on this forum this rule is widely ignored.


ANY bolt that has been tightened has stretched; that's how they work! Angle tightening is specified because it gives more consistent results with simpler equipment than a torque wrench, in blind holes. Where a nut and bolt are used in critical applications (on a conrod big end for instance), you actually measure the bolt stretch with a micrometer.


As for reusing them, 3 M6 bolts to attach a waterpump pulley is already more clamping than is actually necessary to do the job.even an average quality bolt is far stronger than its matching female thread. You can prove that for yourself: put an M6 nut in a vice and tighten a bolt into it with an ordinary 1/4" drive ratchet.
Title: Re: Cambelt HELP!!
Post by: Andy H on 31 May 2016, 19:48:14
Loctite is essential on the water pump pully bolts as they are so physically small that they can't take a lot of torque. They are probably worth  replacing every couple of belt changes, TBH. Mine had been off or a running repair shortly after the last cam belt change and probably didn't get replaced with enough, or any, Loctite.

2 of them had come undone and dropped out. The third one sheared during a spirited climb up a steep dual carriageway. Luckily, I didn't lose the pulley itself and nothing went into the cam belt. The water pump immediately blew its' seal, probably due to instant boiling of coolant in the block as the pressure and flow dropped (like I said, I was driving "spiritedly"). ::)
Thank you gentlemen. Next time I change a cam belt I shall change my procedure in several ways. I see Haynes recommends new bolts and angle tightening for the  power steering pulley too, but not for the crankshaft pulley. I should be nervous of angle tightening 30:30 those small water pump pulley bolts. I was taught that angle tightened bolts should never be re-usued, as they have been stretched beyond their elastic limit on first use, but on this forum this rule is widely ignored.
So called 'stretch bolts' are manufactured from steel which has a certain amount of 'spring'. If you stop tightening a bolt before the spring runs out then it will return to it's original length if you loosen it again. If you carry on tightening a bolt once the spring has run out then you have reached the 'elastic limit' and the stretch (or some of it) is permanent. The bolt material is selected so that the clamping force is known and is not dependent on the amount of lubrication on the bolt threads or the calibration of a torque wrench.

Using stretch bolts for the cylinder head allows manufacturers to build engines that don't need to have the head bolts re-torqued after 500 miles. I struggle to see what VX were trying to achieve though through angle tightening 6mm water pump pulley bolts :-\
Title: Re: Cambelt HELP!!
Post by: gbh on 31 May 2016, 19:52:37
Before your latest replies i popped into the dealership and got the 13mm bolts which i was informed was for the 2.5/3.0 engine. They could order 10 from Luton which did pose me a problem/risk! They are physically different too with the 15mm with separate washer and silver in colour,whilst the 13mm are black and the washer well its a shoulder really as its not separate. What is interesting is that the pulley is different on the 2.5, on mine its hardly thick unless they had problems with the bolt but then they wouldn't be selling it.Perhaps someone could clear that one up? And this might well change the torque values if a different bolt is used as i guess Haynes refers to 2.5/3.0!!
Title: Re: Cambelt HELP!!
Post by: Nick W on 31 May 2016, 20:23:33
Before your latest replies i popped into the dealership and got the 13mm bolts which i was informed was for the 2.5/3.0 engine. They could order 10 from Luton which did pose me a problem/risk! They are physically different too with the 15mm with separate washer and silver in colour,whilst the 13mm are black and the washer well its a shoulder really as its not separate. What is interesting is that the pulley is different on the 2.5, on mine its hardly thick unless they had problems with the bolt but then they wouldn't be selling it.Perhaps someone could clear that one up? And this might well change the torque values if a different bolt is used as i guess Haynes refers to 2.5/3.0!!






The torque is unlikely to change as the threaded part is effectively the same; it's only the first few threads that actually do anything.




There are two different thicknesses of waterpump flange, hence the difference in bolts. You wouldn't believe the whining that being supplied a thinner flanged pump causes!

Mine has been attached with three M6x15 grade 8.8 bolts and stamped washers, costing maybe £0.10 in total and tightened with a 10mm spanner, for five years:

(https://www.dropbox.com/s/hxqwumu8uane1y6/Waterpumpbolt.jpg?dl=1)




No torque wrench, angle gauge, Loctite or worrying needed.
Title: Re: Cambelt HELP!!
Post by: gbh on 31 May 2016, 20:30:35
I wouldn't disagree with you but Vauxhall seem to have gone to an awful lot of trouble for what?
Title: Re: Cambelt HELP!!
Post by: gbh on 31 May 2016, 20:34:11
He is my conversation with the dealership!!!  Glenn
 
  I Totally agree with your comments.
 
  I have just spoke to a mechanic & they seem to think the 13 mm length would be ok.
 
  I m happy for you to try these & if they work great- if not we  will give you a full refund & review the situation.
 
 
 
 
Regards
Nick Organ
01242 531952
 
-----Original Message-----
From: glenn harper <gharper1962@live.co.uk>
To: "Nick Organ" <Nick.Organ@baylis.uk.com>
Date: Tue, 31 May 2016 08:50:51 +0100
Subject: Re: y248lbd
 
Hi Nick, I just measured and they seem to be 15mm but i’m very reluctant to buy 10 as i only require 3 maybe the shorter ones would do. What do your mechanics use? Many thanks Glenn
 
From: Nick Organ
Sent: Tuesday, May 31, 2016 8:24 AM
To: gharper1962@live.co.uk
Subject: y248lbd
 
Good Morning
 
  Thank you for your enquiry.
 
  There are 2 part numbers listed for what you require. The only difference I can see is the length of the bolt.
 
  We carry 1 part number  in stock ,  its a M6 BOLT  length 13 mm in stock  -  3 of these would cost- £3.13 inclusive of v.a.t
 
    the other is  15 mm length.  we would have to order a minimum of 10 - £10.56 inclusive of v.a.t
 
    would you like me to put the ones in stock by for you to collect from a Baylis  Branch  of your choice?
 
 
Regards
Nick Organ
01242 531952