Ducato timing belt bolts

[colin]

Ducato 2011 2.3, am changing the timing belt, I note that the timing belt kits (Fiat and aftermarket) include a new bolt for idler pulley (and idler pulley on aux drive belts), but not the tensioner pulley, this would seem to indicate that the idler pulley's are held on by stretch bolts, but tensioner pulley is standard flanged bolt, the markings on the tensioner pulley are so badly impressed it's hard to tell what it is. So bearing in mind previous threads on this subject, does anyone know for certain if this bolt needs changing?

[colin]

To add to above post, I have ordered a replacement bolt for tensioner pulley from Fiat, as Euro Car Parts cannot supply the bolt.

The bolt they do supply in kit is for the idler pulley, and in place of the Fiat style bolt with large flange, they (SKF) have substituted a bolt with small flange and washer to bridge the gap, I'm not too happy with this as it seems a bodge, if it's fine to refit the original (which looks hardly used) I'd rather do that. 

[John52]

I hoped someone with more recent and relevant experience than me would reply, like someone who had fitted Ducato timing belts!

But since they haven't I'll try and help.

My experience of working in a garage and talking to other mechanics is that they rarely, if ever, renewed stretch bolts when they were supposed to do.

So I re-used the same big end and main bearing crankshaft bolts too.  And that always seemed to be OK.

So I feel sure that since this bolt is so hard to obtain they aren't replacing that either.

Personally, based on many years of working on other engines, I would rather re use the original if I was in any doubt about the new one.

But I can't tell you to re use it.  If you do re use it you do it at your own risk the same as we did.

[John52]

as an afterthought I think its a bit like where Fiat say that if you fit a secondary battery it should not be more than 20% of the capacity of the orginal.  Which would be 20 amp hour, a useable capacity of 10 amp hour.  Clearly inadequate in a camper van, just a way of Fiat evading liability if the alternator fails.

My secondary battery bank is 4x100 amp hour, thats 20 times Fiats maximum recommendation.  Connected in parallel with the main battery by a relay controlled by the ignition switch (through the cigar lighter wire) Its still working fine after 2 years.  (although it sometimes brings on the stop/start not working engine yellow light warning, which I can clear with a basic code reader) 

But I can't tell you to ignore Fiats recommendation.  If you do it you do it at your own risk, same as me.

[Robinhood]

I think that on this forum, the advice to replace the bolt came from Nick Fisher (Euroserv). ISTR there may have been more explicit posts, but the following link certainly seems to advise replacement rather than re-use.

Euroserv Tensioner Bolt

[colin]

The tensioner bolt I have no problem with replacing, it's on order and expected in at our 'new' Fiat Pro garage. it's the bolts for idler pulley's I'm considering reusing as the replacement ones in SKF kit are not to original spec, and I'm not sure why new ones are supplied.

A little aside, previously I've dealt with three Fiat Pro garages and have found them to offer a very poor service. When realising I needed to order a new bolt from Fiat I looked up the nearest Fiat Pro, and they where no longer listed, so I looked up the second nearest, these have changed and now it's 'Northern Commercials' at Dunstable, the people there where very helpful with regard to sorting out parts, although they could offer no reason as to why Fiat (and others) supply new idler pulley bolts, and the only way they could get new idler pulley bolts was with a complete kit, and they even found a 'cheaper' Iveco kit which contained the idler pulley bolt, although this was still over £100. 

[david lloyd]

My only experience was a Hobby we bought from a dealer near Nottingham some years ago who included a cam belt change as part of the deal. First trip was from North Yorkshire to Sussex and Kent. Just before our first campsite the engine faltered and lost some power but limped into the car park. The dealer had not replaced the tensioner bolts which slipped and had a similar effect to the cam belt failing. Fortunately, not much damage other to the valves but it did mean being collected by a rescue vehicle taken back to the dealer, trip back home in a courtesy car then return a week later to finish our trip - luckily under warranty.

I am having my cam belt done on the Renoir soon and have asked to replace the bolts with new.

David

[John52]

2 hours ago, david lloyd said:

The dealer had not replaced the tensioner bolts which slipped

Sometimes thats because the new bolts are pre-coated with thread locking compound

If there is a box of new bolts to hand and main dealer hourly rates its cheaper to fit new bolts than pay the mechanic to clean and apply locking compound to the old ones.

But if you have got to go to the trouble and delay of sourcing new bolts its cheaper and quicker to clean up the old ones and apply fresh thread locking compound

If they tightened them correctly and they still slipped, it sounds to me like they didn't use thread locking compound when they should. 

[david lloyd]

Yes you could be right John - either way it was a long drawn out week for us and a bit of a bind for the dealer.

David

[John52]

If you got the proper bolts from Fiat it would be interesting to know if they have got thread locking compound on.  Which seems to me the most likely reason why they recommend fitting new bolts.  I haven't seen them, but it sounds like they are subject to a lot of vibration, but not a lot of stress.  So there is no danger of the old bolts snapping.  Just coming loose if they are not coated with thread locking compound like the new ones.

[onecal]

Hi

TTY stretch bolts should only be used once and be replaced and tightened to the correct torque and angle every time when refitting the timing belt

TTY bolts should never just be cleaned and refitted. 

Regards

[John52]

7 hours ago, onecal said:

Hi

TTY stretch bolts should only be used once and be replaced and tightened to the correct torque and angle every time when refitting the timing belt

TTY bolts should never just be cleaned and refitted. 

Regards

 

That seems to be the manufacturers recommendation, and the easiest thing is just to repeat it.  Like saying your secondary battery should not be more than 20 amp hour - thats a Fiat recommendation too.

But if new bolts are not readily available, what are the chance of the old bolts failing?

Have you reused old bolts and they have failed?

From my own experience of years working in a garage re-using old bolts (with new thread locking compound where appropriate) they never failed.  But we didn't advertise the fact we were not always following the manufacturers recommendation.  It wouldn't have been good for business.  And people might have blamed us for other things failing that were unrelated to not following the manufacturers recommendation.

[onecal]

LOl 

Again your risk if you want to take it. But far from good engineering practice, of course as you know

They are TTY bolts not just old bolts ,  so why again take the risk if they break and they do 

TTY stretch bolts should only be used once and be replaced and tightened to the correct torque and angle every time when refitting the timing belt

TTY bolts should never just be cleaned and refitted. 

Regards 

Edited May 1, 2023 by onecal

[John52]

I bet they all say they use new bolts.  But the fact their suppliers don't sell them  tells me that they don't.

To be sure you could fit new everything - giving you a new van which could still break down.

[onecal]

Hi John 

I can only speak for myself and I can assure you I do every time with a new water pump also, as the pumps do go especially in motorhomes that do low mileage    

Do it once and do it right 

Otherwise sure why bother replacing anything correctly 

Preventive maintenance is to prevent breakdowns 

So always replace those TTY bolts with new ones every time

I hope that answers your question Colin  

Regards 

Edited May 1, 2023 by onecal

[colin]

1 hour ago, onecal said:

So always replace those TTY bolts with new ones every time

I hope that answers your question Colin  

Regards 

Sort of, but I'm still puzzled that AFAIK the kits include the idler bolts, but the tensioner bolt has to be purchased separately.

[onecal]

Hi,

Afraid that's life, one could always ask the kit manufacture you purchased or indeed the supplier of same. Answers may be interesting . 

One very important point is always make sure you replace any TTY bolts with new ones every time 

Regards

Edited May 1, 2023 by onecal

[colin]

I've asked both SKF and Euro Car Parts why they have supplied (what I consider) a bodge for idler bolt, they don't want to discus it. Also Euro Car Parts say they cannot supply a replacement tensioner bolt, so I've ordered one off Fiat (Northern Commercials), my feeling is it would be better to reuse the original Fiat bolts on idler than the SKF bodge.

[onecal]

Again I cannot comment for them, I find it strange they refuse to give you an answer , why! 

It's not expensive to purchase a new one 

The TTY bolts should be replaced every time and never cleaned and reused 

So my advice is purchase a new one on replacement

Regards 

[colin]

Whilst the tensioner bolt is available as a separate part, the idler bolt isn't. As Euro Car Parts refuse to refund on the SKF kit (had it over 60 days) this means buying a new kit from Fiat to ensure I get correct bolt.

[onecal]

Hi 

These things happen , If you are not happy with the kit , then don't use it. why would you take a chance 

Put it on e bay if you are unable to get a refund, or get legal advice.

I am sure some one may purchase it and hopefully purchase a new bolt for same and never take a chance in not replacing TTY bolts 

I would not like anyone to read this thread and be mislead into thinking it was ok to just clean TTY bolts and reuse them 

Regards  

[John52]

Lets not fall out over it 🙂

You are bound to get differences of opinion asking a question like this on a public forum.

I wouldn't have thought tensioner and idler pully bolts would be TTY?- just ordinary bolts with thread lock you can make good as new.

TTY bolts I agree are better renewed.

That said we have re used them - not stretching them again, just the normal torque plus a little bit so they are about the same stress as they were before - and AFAIK they have always been ok.

When you have got a vehicle needed elsewhere in bits clogging up the workshop, other vehicles lined up waiting to come in, you are not going to keep it there indefinately waiting for new TTY bolts - not if you want to stay in business.

[onecal]

Hi John

Not at all , great to have a discussion as we all pick something up along the way  

TTY bolts are not able to do their job second time around 

I would not like anyone to read this thread and be mislead into thinking it was ok to just clean TTY bolts and reuse them 

Regards  

[david lloyd]

As mentioned earlier in the thread I am hoping to have the Renoir serviced and new cam belt fitted shortly. Was there a popular consensus as to what else should be replaced as a matter of course - water pump? tension bolts? idler/bolts?

David

[Robinhood]

David,

 It just occurred to me that the (Autocruise) Renoir was (AFAIR) built on the Peugeot Boxer, where the 2.2 and 3.0 engines both had a chain, not a belt. A completely different kettle of fish.

 My memory may be playing up, or you may have one of the rare Autocruise vans built on the Fiat (I have a friend with such a PVC). Worth a thought, though.