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[05omegav6]

Actually I have done a timing belt. On the vectra in situ which is a much harder job than the omega in situ. I make my living as a mechanic - running my own workshop, so I've probably seen my fair share of jobs.

A lot of experience there may be, I'm not disputing that.

So can someone please tell me why its impossible to time a v6 engine without the locking kit? The cams are locked together in a position, why is it so meant to be so hard to replicate this position? You know instantly if you're a tooth out on the belt because the marks end up way off. After you've sycronized 5 pulleys together its just down to the eccentrics for fine tuning. So why can this only be achieved with a locking kit?

For a start, the belts are rarely marked, even genuine ones Locking the cams also ensures that the cams won't move if accidentally knocked...

If the locking kit is used, as recommended, then it's a significant job made easy. The implications of getting it wrong are all too obvious

Do you have liability insurance covering your work, and if so do they cover your work if you don't use task specific tools?

Put it another way, if you changed my cambelt without a locking kit and the belt failed, you would be paying for a new engine plus associated costs

[Kevin Wood]

Firstly, because the cam timing must be set using the eccentric adjusters to a resolution of  less than one tooth. Getting it within a tooth is not sufficient.

Secondly, the timing marks on the backplate are not accurate enough, and the proper kit provides a jig with accurate alignment marks.

Thirdly, you're going to have a bit of a game getting the belt over 4 cams without anything moving and the proper kit has locking tools for this purpose.

I have probably done the job a dozen times and I could get it to the point that the engine will run without the kit, no doubt. It wouldn't be to an acceptable standard, though, and would take me at least twice as long, without doubt.

Given that the proper locking kit costs much less than a decent quality belt kit, I just wonder why anyone would put themselves through the pain of doing a cowboy job without the kit. If you're new to the engine or doing your own maintenance then you will get into a complete mess without the proper locking kit hence the advice here is and will remain that you do need the locking kit to change a v6 cam belt.

[chrisgixer]

Personally I don't agree with the common line on here that its not possible to change the belt without a locking kit. BUT its a million times easier, quicker, safer and much more accurate to use a locking kit than not.

I liken the the timing marks on the belt cover backing plate and crank pulley as a mechanical version of the pedal trick and paper clip test for fault codes on electrics. These tricks where included for diagnosis in countries where a diagnostic tool is rare or non existent. Tech2 might be hard to come by.

Same with a locking kit, it might be hard to come by in poorer countries. So there MUST be a way to change the belt with out a kit. Same as there is a way to read the codes without tech 2.

However, what's different about the v engine is the 4 cams need setting 2 per bank. This adjustment is infinite. It's not a case of just getting the belt on the correct teeth and set the tension. You have to position each pair of cams to within a millimetre of the timing gauge in the kit, by adjusting the tension of the top and bottom roller(if adjustable, some aren't on the Dbw cars) in order to get the timing and hence performance to its optimum.

It's very easy to be a tooth out with out the kit/using the back cover marks, and we know that performance suffers if its that far out going by old posts on here. 


So, its possible to change the timing belt, tensioner and rollers (must be done as a set as its the bearings that fail) without a locking kit, but I'd never recommend trying.

ALWAYS acquire a locking kit. Two cam locks, crank lock, setting gauge, wedge, and ring spanner. ALWAYS.

[chrisgixer]

Ah, way too slow.

[serek]

 if you dont use locking tool, and you get faulty timing belt kit and something go wrong then suppler have rights valid warranty

[AndyStobbs]

Of course I'm insured; I'm not playing at being a mechanic. I was referring to marks on the back plate for an indicator of being a tooth out, granted they aren't perfect but do serve. Re: the eccentrics the one between the banks has a limited range of movement before again the marks drift away from back plate notches, and if the other one is too far out the tensioner won't get enough tension on the belt and can be seen to be sitting wrong.

When I said about the pulleys looking at each other I meant with the green tool a tooth on one pulley opposes a trough on the other pulley. The red tool leaves the centre lines of a tooth on each pulley looking at each other.

So in my opinion with a little bit of prior knowledge (or instruction) of how the pulleys sit when correctly adjusted, its entirely possible to make a perfect job of timing without a kit.

Also for the record the mark on the front pulley is a perfect datum for the centre of TDC, I verified it with a degree wheel and DTI.

With some observation of the positions before removing the old parts and a bit of patience anything is do able. If I bought the locking kit for every car I worked on I would never make any money, and I've not had an issue yet.

[Andy B]

....
With some observation of the positions before removing the old parts and a bit of patience anything is do able.  .....

Assuming the belt was fitted correctly in the first place.  It's been noted a few times by those that work on the Omega V6 a lot, that many belts are a tooth or more out in te first place. 

[chrisgixer]

Of course I'm insured; I'm not playing at being a mechanic. I was referring to marks on the back plate for an indicator of being a tooth out, granted they aren't perfect but do serve. Re: the eccentrics the one between the banks has a limited range of movement before again the marks drift away from back plate notches, and if the other one is too far out the tensioner won't get enough tension on the belt and can be seen to be sitting wrong.

When I said about the pulleys looking at each other I meant with the green tool a tooth on one pulley opposes a trough on the other pulley. The red tool leaves the centre lines of a tooth on each pulley looking at each other.

So in my opinion with a little bit of prior knowledge (or instruction) of how the pulleys sit when correctly adjusted, its entirely possible to make a perfect job of timing without a kit.

Also for the record the mark on the front pulley is a perfect datum for the centre of TDC, I verified it with a degree wheel and DTI.

With some observation of the positions before removing the old parts and a bit of patience anything is do able. If I bought the locking kit for every car I worked on I would never make any money, and I've not had an issue yet.

This is exactly why we see members posting/joining up to see why their car runs like a bag of shite, only to find the car has been worked on by a mechanic with exactly that approach. The end of which sees members posting up demanding to name and shame the garage concerned.
Its your lively hood though, so up to you of course.

Yes I've done a v6 with no locking kit in my pre forum days, and having now used one on several occasions, there's no way to guarantee accuracy without it. None.


Whilst I fully appreciate a mechanic has to deal with numerous models in a daily basis, and you have my sympathies there, you also need to remember that we have the luxury of concentrating on one model alone on here. There's a few members here that know this car very well indeed.

There's no way on earth I'd take my car to a mech with this approach, sorry, but no.

[AndyStobbs]

That's your opinion, you're entitled to it. And you're not alone, loads of people would side with you. Would love to do some dyno runs with the timing set in various places and compare to the proper set up, just for the hell of it, because I like experimenting. It'll have to wait until I get an omega though (if ever) because its too long winded to play with the vectra timing in situ.

[2boxerdogs]

Of course I'm insured; I'm not playing at being a mechanic. I was referring to marks on the back plate for an indicator of being a tooth out, granted they aren't perfect but do serve. Re: the eccentrics the one between the banks has a limited range of movement before again the marks drift away from back plate notches, and if the other one is too far out the tensioner won't get enough tension on the belt and can be seen to be sitting wrong.

When I said about the pulleys looking at each other I meant with the green tool a tooth on one pulley opposes a trough on the other pulley. The red tool leaves the centre lines of a tooth on each pulley looking at each other.

So in my opinion with a little bit of prior knowledge (or instruction) of how the pulleys sit when correctly adjusted, its entirely possible to make a perfect job of timing without a kit.

Also for the record the mark on the front pulley is a perfect datum for the centre of TDC, I verified it with a degree wheel and DTI.

With some observation of the positions before removing the old parts and a bit of patience anything is do able. If I bought the locking kit for every car I worked on I would never make any money, and I've not had an issue yet.

This is exactly why we see members posting/joining up to see why their car runs like a bag of shite, only to find the car has been worked on by a mechanic with exactly that approach. The end of which sees members posting up demanding to name and shame the garage concerned.
Its your lively hood though, so up to you of course.

Yes I've done a v6 with no locking kit in my pre forum days, and having now used one on several occasions, there's no way to guarantee accuracy without it. None.


Whilst I fully appreciate a mechanic has to deal with numerous models in a daily basis, and you have my sympathies there, you also need to remember that we have the luxury of concentrating on one model alone on here. There's a few members here that know this car very well indeed.

There's no way on earth I'd take my car to a mech with this approach, sorry, but no.

Quite agree with this, makes a lot of sense to me, my mechanic did my 2.2 including the waterpump, has said he wouldn't do the 2.6 as he did not have the correct tools for it.

[darrenfos]

I will defo use the kit and watch the dvd and use the manual for torque settings thanks for the help, i can do most jobs as long as a ramp is not needed but u should never be afraid to ask for advise, u never stop learning.

[dbug]

Of course I'm insured; I'm not playing at being a mechanic. I was referring to marks on the back plate for an indicator of being a tooth out, granted they aren't perfect but do serve. Re: the eccentrics the one between the banks has a limited range of movement before again the marks drift away from back plate notches, and if the other one is too far out the tensioner won't get enough tension on the belt and can be seen to be sitting wrong.

When I said about the pulleys looking at each other I meant with the green tool a tooth on one pulley opposes a trough on the other pulley. The red tool leaves the centre lines of a tooth on each pulley looking at each other.

So in my opinion with a little bit of prior knowledge (or instruction) of how the pulleys sit when correctly adjusted, its entirely possible to make a perfect job of timing without a kit.

Also for the record the mark on the front pulley is a perfect datum for the centre of TDC, I verified it with a degree wheel and DTI.

With some observation of the positions before removing the old parts and a bit of patience anything is do able. If I bought the locking kit for every car I worked on I would never make any money, and I've not had an issue yet.

You need to recognise mate that not everyone is as clever as you ( ), and the forum advice is aimed at all members, hence the forum recommendation to use the correct locking kit.  It never helps for the odd member who thinks he knows better than some of the guru's on here to post "bad" advice which others may follow with bad results.

[AndyStobbs]

Thanks for levelling with me, I appreciate what you're saying, in hindsight you're right. I should stick to least said, soonest mended.
just pains me to see people spending money on gear when they could manage without if only for the want of the right instruction.

[darrenfos]

Anyone know how much the gm belt kit is.

[dbug]

Thanks for levelling with me, I appreciate what you're saying, in hindsight you're right. I should stick to least said, soonest mended.
just pains me to see people spending money on gear when they could manage without if only for the want of the right instruction.