Timing belt change diy

pappajohn said:
Good idea in theory, but the old belt will have stretched VERY slightly so THE teeth MAY NOT line up with the new belt.
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If that occurred by any serious amount the teeth on the belt would no longer fit the sprockets.
 
Pretty sure you also need a new idler pulley bolt if it's not in a kit. I was told it's a stretch bolt and if you reuse it's not unknown for them to break. Someone else may know more or comment?
 
PP Bear said:
Just done my 2006 JTD all be it on an Autotrail.

2 man job to undo the dif bolt if someone’s available. On mine there’s a clear section cut out at the bottom of the gearbox and I easily inserted a screwdriver that locked the flywheel, while someone else loosened the nut.

Refit of the dif bolt was the same procedure.

No requirement to lock the cam shaft either and the timing marks were clearly visible.

Can’t imagine how tight it must be on an A class. That'll teach you, should have got a real motorhome and none of that fancy A class rubbish :clap2::party::rofl:
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Dont know but all engines need the similar locking procedure - access may or may not be difficult my A class is as easy as a van ie not that restricted but it is 18yrs old
 
mfw said:
Dont know but all engines need the similar locking procedure - access may or may not be difficult my A class is as easy as a van ie not that restricted but it is 18yrs old
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The Inner wings On an A class are normally the same as a panel van so shouldn’t make any difference to changing the cam belt
 
My two Penny's worth ,don't go for a cheepy belt either.
Gates or similar is recommended (fiat forum) did mine last year had done 74000klms but had stood around for a good while choice of 2 belts from memory 154 teeth or 153 teeth (?)
Water pump does need a change 2.5tdi fiat 1998.

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Roger20 said:
Pretty sure you also need a new idler pulley bolt if it's not in a kit. I was told it's a stretch bolt and if you reuse it's not unknown for them to break. Someone else may know more or comment?
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Never heard of any such a thing in all my years.

A stretch bolt is normally designed to pull machined mated surfaces together, such a cylinder head.

No such requirement on the crank bolt, it's flippin huge in terms of a stretch bolt and 200Nm isn't stretching it at all:)
 
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jollyrodger said:
My two Penny's worth ,don't go for a cheepy belt either.
Gates or similar is recommended (fiat forum) did mine last year had done 74000klms but had stood around for a good while choice of 2 belts from memory 154 teeth or 153 teeth (?)
Water pump does need a change 2.5tdi fiat 1998.
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It baffled me too when I was searching for a good quality belt.

Went with a Gates as they're class leaders in this field.
https://www.gates.com/us/en/power-t...iming-belt-component-kits-w-water-pumps/c/156
 
tonyidle said:
If that occurred by any serious amount the teeth on the belt would no longer fit the sprockets.
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The teeth would not stretch as the material is at least twice as thick as the flat section of belt between teeth.
I did also say SLIGHTLY, not by a serious amount.
 
PP Bear said:
Never heard of any such a thing in all my years.

A stretch bolt is normally designed to pull machined mated surfaces together, such a cylinder head.

No such requirement on the crank bolt, it's flippin huge in terms of a stretch bolt and 200Nm isn't stretching it at all:)
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It was the idler pulley bolt, not crank pulley bolt that was mentioned. I’ve got stretch bolts on a suspension subframe so they can be on any vital bolt, but I would think where the main force is in the same direction the bolt is holding, not sideways as an idler pulley. You would think if required it would be included in the best kits.

The water pump changing may not be a requirement, but on most vehicles it’s considered good planning as they’re often driven by the timing belt and/or if doing the belt you’re so far into the process for water pump replacement you might as well do it while you’re there as the ‘cost of part vs its longevity’ calculation says it makes sense.

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thank you all for your replys i have since found out that the water pump on my MH is nut part of the timing belt as was mentioned on here but i also found out that you get 2 idler pulleys 1 a steel and 2 what looks like a nylon one with a £60:00 price differnce .
 
PP Bear said:
Never heard of any such a thing in all my yearsUOTE]
PP Bear said:
Never heard of any such a thing in all my years.

A stretch bolt is normally designed to pull machined mated surfaces together, such a cylinder head.

No such requirement on the crank bolt, it's flippin huge in terms of a stretch bolt and 200Nm isn't stretching it at all:)
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Are you an engineer? If you read what I posted I referred to the idler pulley bolt not the crankshaft bolt. There are lots of stretch bolts that could possibly be safely reused but the idler pulley one is not one I personally would risk. I am in a Fiat workshop today and will ask the question.
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wfdTamar said:
Re: Idler pulley bolt - Can you ask if that applies to all the Ducato engines (I have a 2.8 JTD)?
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As mentioned I did my cam and auxiliary belts last Saturday.

Straight forward job and no requirement to change the idler bolts, as they're held on by nuts, not bolts. Also no requirement to lock the engine or cam in place as it's not moving once you've timed the engine up.

Unless you find any reason to change the water pump I'd leave well alone, it's not driven by the cam belt, but does house the cam belt tensioner.

I'd also go with a Gates replacement kit and it contained new idlers that are steel and not nylon.

I also changed my top engine mount (at £60 it's worth it) as mine sheared after the previous belt change (by a garage), which dropped the engine at 50mph, damaging the drive shaft gaiter.

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I have used the longitudinal belt split method quite a few times without issue
 
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210ians said:
pp Bear what age and milage is your MH if i can ask
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2006 and now on 34300 miles.

I've had it 7 years (August 2012) and this is the second cam belt change, as I couldn't verify if it had been changed before I brought it.

I had no workshop facilities when it needed changing the first time (2013) so trusted it to a garage. Some months later the bolt that holds the 2 parts to the top mounting sheared and the engine dropped quite some distance and impacted on the driveshaft, splitting the gaiter, but luckily no other damage. Mind you, that was enough as the gaiters are a pain to change. The garage had told me at the time of them doing the belt, that they had to re-tap a mounting bolt thread, so I'm guessing that they might not have done the job correctly, but was months later when the bolt sheared.

My advice is either change the entire mounting, or remove the 6 bolts holding the mounting and remove the entire thing, so as not to need to release the single mounting bolt.

A small 2 ton trolley jack and a block of wood supported the engine and was then gently lowered giving much improved access to both the alternator tensioner and cam belt.

Hope I'm not teaching you to suck eggs, but remember to loosen all the required bolts on the alternator so as to not put the tensioner bracket under any undue stress and then pinch them back up again after refitting a new auxiliary belt.

There are some YouTube videos of the 2.8JTD belt being changed, not in English unfortunately, but gives a good insight into the system and pulleys and the tensioner.
 
PP Bear can you tell me where you got the parts no for your kit as I found a kit quite a lot cheaper which has a different part no or is your van different year to mine
Best price T,B, kit 31473921 supposed to be gates kit as well ? £43:83
2 bearings and a belt .

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Also when we look for parts always we get so many different models and as only the cab is used on our MH what do we look for
And engine no seems to start 850 mine starts 395 do you find same problem or is there an easy way to determine which vehicle we have or is it me
 
PP Bear said:
2006 and now on 34300 miles.

I've had it 7 years (August 2012) and this is the second cam belt change, as I couldn't verify if it had been changed before I brought it.

I had no workshop facilities when it needed changing the first time (2013) so trusted it to a garage. Some months later the bolt that holds the 2 parts to the top mounting sheared and the engine dropped quite some distance and impacted on the driveshaft, splitting the gaiter, but luckily no other damage. Mind you, that was enough as the gaiters are a pain to change. The garage had told me at the time of them doing the belt, that they had to re-tap a mounting bolt thread, so I'm guessing that they might not have done the job correctly, but was months later when the bolt sheared.

My advice is either change the entire mounting, or remove the 6 bolts holding the mounting and remove the entire thing, so as not to need to release the single mounting bolt.

A small 2 ton trolley jack and a block of wood supported the engine and was then gently lowered giving much improved access to both the alternator tensioner and cam belt.

Hope I'm not teaching you to suck eggs, but remember to loosen all the required bolts on the alternator so as to not put the tensioner bracket under any undue stress and then pinch them back up again after refitting a new auxiliary belt.

There are some YouTube videos of the 2.8JTD belt being changed, not in English unfortunately, but gives a good insight into the system and pulleys and the tensioner.
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I note you mentioned that the bolts failed some time after having a garage change the belt.
I also came across this problem , not on a Ducato, but it's still relevant.

Many engine mounting bolts and the like on relatively modern vehicles are torque to yield (TTY) applications , sometimes known in the industry as 'stretch bolts'.

On any bolt as you apply angle and thus torque to the bolt the tension , or clamp load, that the bolt applies rises, usually in a relatively linear relationship.
You are working within the elastic limit of the bolt.
Bolts that do not exceed this limit can be reused.

However, once you get beyond the the elastic limit the bolt will go into yield.
In this range the clamp load , simplified, does not increase in proportion to angle or torque.
Turning the bolt someway beyond this limit will reach breaking point.
Bolts that have been yielded must usually be replaced.

Often you can tell a bolt is being used in a TTY mode as it will often have a snug torque and then an angle to tighten it. This ensures you yield the bolt.

Many garages do not know this, or perhaps choose to ignore it and maybe get away with reusing the old bolts.

Why do designers use TTY bolts?
If a bolt uses a TTY regime the clamp load can be delivered with great reliability and you have always reached the maximum clamp load that the bolt can apply, therefore the bolt size can be perhaps one size smaller than it's elastic limited partner and thus lighter and more compact.

I have VW's , they bolt use TTY bolts on the mounts that have to be removed the replace the belt.

How do I know ?. replaced the belt on my daughters Skoda and 2 weeks later the bolts failed with a similar outcome as the note above. The Haynes manual I was using did mention yield bolts but in a small note which I missed.
 
210ians said:
PP Bear can you tell me where you got the parts no for your kit as I found a kit quite a lot cheaper which has a different part no or is your van different year to mine
Best price T,B, kit 31473921 supposed to be gates kit as well ? £43:83
2 bearings and a belt .
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I reviewed the Gates website for the part number of the belt kit and then searched for the part required on fleabay.
 
PP Bear I just put in my search fiat ducato 2.8 jtd 2004 Timeing belt kit and several came up including the one I said but when you check to see if it,s compatible you get 20 plus different models as I said we only use the cab so a bit of a minefield for anyone looking for parts ?

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If you look at the V5 registration document you’ll find the engine number and hopefully the engine code as well
 
We order cambelt kits from a major suoplier via Reg No, they then use DVLA to cross referance vehicle exact details
Even then we are often supplied with 2 or 3 of the most common kits for that vehicle as thats as close as they can get
1 kit for 1 vehicle is a bit of a Myth
 
Re PP Bear,s problem with broken engine mount I had a look at mine and its just lock nuts that hold my mount I think I know what may have happened to your mount when garage did your T/b they used old locking nuts which are ment to be replaced every time you use them this happened to me with a car a few years back and when I spoke to garage owner he said yes we did run out of that type of nuts but I told mechanics to use 2 normal nuts instead till we get locking nuts in ? As you can imagine they didn't and nuts came off suspension collapsed

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