Has my belt skipped a tooth?
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Not many rules really, this board being aimed at technical issues, it shouldn't fall foul (hopefully) of some of the more personal issues that can affect forums.
Rule 1 - Is that you need to think very carefully before posting anything technical or asking anything technical relating to the security system of the car - See 'Security Issues' sticky for more info.
Rule 2 - We (MGF Register) do not support copyright infringement and therefore references to CD ROM, PDF versions or paper copies of the workshop manual (for instance) should not be posted on the forum. We don't want to get into trouble and we'd rather sell you a genuine hard copy through our Regalia shop anyway!
Because advice is honestly and freely given in this technical section, much of it will be amateur experienced based, so any information is given in good faith and is not guaranteed as correct.
Has my belt skipped a tooth?
Hello newbie here!
Just changing the cam belt on my tf 135 2004
Locked the cams in position with the tool, made sure the marks all lined up, fitted the new belt, adjusted the tensioner, then removed the cam tool and rotated the engine over twice, when I repositioned the cam tool with the cam marks aligned, the 2 marks on the crank are slightly off centre now….did it skip on rotation or is this ok ?
Excuse my paranoia! But want it to be ok before I try to start it?
Also is my tensioner ok in this final position? The slot and the wire are in the correct position
Thanks in advance
Bob
Just changing the cam belt on my tf 135 2004
Locked the cams in position with the tool, made sure the marks all lined up, fitted the new belt, adjusted the tensioner, then removed the cam tool and rotated the engine over twice, when I repositioned the cam tool with the cam marks aligned, the 2 marks on the crank are slightly off centre now….did it skip on rotation or is this ok ?
Excuse my paranoia! But want it to be ok before I try to start it?
Also is my tensioner ok in this final position? The slot and the wire are in the correct position
Thanks in advance
Bob
Re: Has my belt skipped a tooth?
Anybody have an idea please?
Thanks
Thanks
- Charless
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Re: Has my belt skipped a tooth?
Hi Bob,
From my not huge experience of doing three and helping with several, I would think you are probably ok there. You would have noticed a tooth skip and the marks on the crank pulley and castings are known not to be deadly accurate
In the absence of expert K series engine builders the best alternative is to set it all up again (oh joy) and see if the pulley dots revert to that same slightly offset position after the two rotations. If they do then it will probably be as accurate as you are going to get but I know the frustration!
From my not huge experience of doing three and helping with several, I would think you are probably ok there. You would have noticed a tooth skip and the marks on the crank pulley and castings are known not to be deadly accurate
In the absence of expert K series engine builders the best alternative is to set it all up again (oh joy) and see if the pulley dots revert to that same slightly offset position after the two rotations. If they do then it will probably be as accurate as you are going to get but I know the frustration!
- mgtfnut
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Re: Has my belt skipped a tooth?
I also say try again.
Start with the crank pulley marks lining up, and get the first cam pulley engaged with the belt. Even with the cam locking tool engaged, there is still a bit of wiggle movement in rotation. This first stretch of belt has to be tight. I find wedging the cam belt against the plastic casing at both ends (crank pulley and cam pulley) to hold this position helps things fall into place.
The position of the tensioner adjusting arm is irrelevent, just ensure the marks line up as you have done.
Best to do it now before the engine is fired up and the belt is in it's new relaxed state.
Good luck.
Start with the crank pulley marks lining up, and get the first cam pulley engaged with the belt. Even with the cam locking tool engaged, there is still a bit of wiggle movement in rotation. This first stretch of belt has to be tight. I find wedging the cam belt against the plastic casing at both ends (crank pulley and cam pulley) to hold this position helps things fall into place.
The position of the tensioner adjusting arm is irrelevent, just ensure the marks line up as you have done.
Best to do it now before the engine is fired up and the belt is in it's new relaxed state.
Good luck.
Jerry
MG TF 135 - 100k
Suzuki SJ 413 - 309k
Skoda Yeti SE 110 4x4 - 131k
MG TF 135 - 100k
Suzuki SJ 413 - 309k
Skoda Yeti SE 110 4x4 - 131k
- RobboMC
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Re: Has my belt skipped a tooth?
Firstly, there's no such thing as excess paranoia when fitting a timing belt, if you're not 200% sure it's right then DO NOT fire it up.
I have found it's quite easy to get the belt one tooth out. Unless the exhaust side run to the crank it held nice and tight you can get an extra tooth on that side of the engine. I found that be leaving the belt on the engine for a week and then removing and refitting it proved successful.
Refitting the belt pulley will give you a better idea of the crank position ( yes I know it's a pain )
I have also found the particular brand of belt supplied by our local MG specialist are easier to fit correctly. I think they stretch in to shape better.
I have found it's quite easy to get the belt one tooth out. Unless the exhaust side run to the crank it held nice and tight you can get an extra tooth on that side of the engine. I found that be leaving the belt on the engine for a week and then removing and refitting it proved successful.
Refitting the belt pulley will give you a better idea of the crank position ( yes I know it's a pain )
I have also found the particular brand of belt supplied by our local MG specialist are easier to fit correctly. I think they stretch in to shape better.
Re: Has my belt skipped a tooth?
Hello
Guys thanks for the replies and reassurances!
As I am waiting for a replacement water pump bolt (the shouldered one) I am going to follow the advice of leaving the belt in place for a few days to take a better shape then remove and refit…..I will post a follow up over next weekend
Thanks again
Cheers
Guys thanks for the replies and reassurances!
As I am waiting for a replacement water pump bolt (the shouldered one) I am going to follow the advice of leaving the belt in place for a few days to take a better shape then remove and refit…..I will post a follow up over next weekend
Thanks again
Cheers
- cbjroms
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Re: Has my belt skipped a tooth?
Difficult to see from your photos. When I did it a few months ago it took a few attempts to get to a position where I was happy. Even with the cams locked in place, slackness in the belts makes it tricky to get 'right first time'.
- Reckless Rat
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Re: Has my belt skipped a tooth?
Correct belt tension should enable you to rotate the belt 90° on its long run from the exhaust cam wheel to the crank.
With the cam locking tool in place it may be necessary to "ease" the crank pulley slightly to get the belt in place, but it should still be aligned with the casting mark between the two dots on the crank, as in this pic: (you can see a slight offset, but that's OK)
With the cam locking tool in place it may be necessary to "ease" the crank pulley slightly to get the belt in place, but it should still be aligned with the casting mark between the two dots on the crank, as in this pic: (you can see a slight offset, but that's OK)