Info from Gates regarding cam/timing belt wear
 

I thought I'd post a link to some info from Gates (who made the OEM cam belts on the KV6 for the 75) which I got in an email newsletter from them.

It is regarding wear on cambelts:

https://www.gatestechzone.com/en/news/2019-11-wear-analysis-timing-belts?utm_source=flexmail&utm_medium=e-mail&utm_campaign=gatestechzonenewsletterdecembere xternal&utm_content=more+info+gtgtgt

May be of interest to petrol owners (CDT owners have no cares in this department!).

The paragraph at the bottom is most interesting (and worrying!).

.............................. it is not as though Gates (and other manufacturers) dont have vested interest in replacement ......................... :duh:

.............................. in my experience ya da ya da ....................... :duh:

:rolleyes::rolleyes::rolleyes::rolleyes::rolleyes: :rolleyes::rolleyes::rolleyes:


;)

:getmecoat:

Very interesting and informative, with pictures of (probably premature) damage caused by various alignment / tension problems, other than just mileage.

However, have I missed something about the actual age of a belt?

From my reading, it appears that a (correctly installed) belt will wear with miles, but not (specifically) with years.

An article to bookmark, never the less.

I believe Dayco developed the system on the KV6 - from Wikipedia:

'The V6 engine is fitted with four overhead camshafts driven by synchronous tooth belts. It has a single, long, serpentine belt at the front driving the inlet cams and also the coolant pump. The exhaust cams are driven by short link belts driven from the ends of the inlet cams at the rear of the engine. The system was a joint development between Dayco (belt supplier) and Rover.'

Interesting, nonetheless :)

Nothing new then - its what I would expect to check should a service interval dictate. Otherwise change by the mileage and/or age as per engine manufacturers recommendations.

Last year my son bought a 15 year Fiesta with 110k on the clock, the old chap he bought it from had it from new and had never had the belt replaced. The car came with every service sheet and invoice from new including bulbs replaced and tyres inflated :eek:.

We obviously replaced the belt and apart from the printing being a little scuffed there was little or no sign the belt had any ware.

A garage mechanic friend had car brought in to his workshop that would not start. It had covered less than 20k from new but was about 5 years old. After a bit of investigation he found the timing belt had snapped. No obvious reason as the tensioner was free to rotate and no oil contamination. When he asked about this from a dealer selling this make of car they did admit they had a few that had done this under warranty but this vehicle was no longer covered.

Timing belts seem to be a lottery, many will go well pass there service life but there is always seem to be some that fail for no apparent reason.

What I find interesting is that the fatigue life of the glass fibre is down to number of engine revolutions but the car's service interval indicator system doesn't seem to play any part in determining the belt-change point (I am assuming it can count revs and in doing so can adjust the interval for ordinary services.

Length of time since fitting and mileage do not necessarily have a linear correlation to age/mileage - plus I remember reading somewhere that the number of starts an engine makes (when belt is at greatest load) also makes a difference.

Correct, I have read posts by 1955diesel, the man who developed the system, stating that it was done with Dayco - but that was for the original KV6 used in the 800.

For the revised KV6 used in the 75/ZT/45/ZS the belt supplier swapped to Gates (although I believe that the specification of the belts and the part numbers remained the same).

what I suspect would be if the car was driven hard, ie the amount of torque called upon would have a bearing on its wear. If the revs were to be counted, it wouldnt take account of its use.

Additionally I reckon the ambient temperatures could come into play. eg if in a frozen or a very hot area, and the engine not run for a period of time - the belt materials would become firmer or softer. So the manufacturers would err on the side of caution.

Yes I agree - and I assume the existing service interval indicator also goes on the side of caution.

Given that manufacturers won't want a reputation for engine failure I am sure a large dose of caution is added into the schedules (hence the schedules can be exceeded, sometimes by a long way, before belt failure).