Volvo D4 260 hp Compresser Serpentine Belt

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CHI

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I have released the tension on the front Alternator serpentine belt for the winter so it does not form a set.Re- tensioning straight forward enough with Torque figures in handbook. However i wish to release tension on rear compressor belt also. Nothing in handbook ? Does anyone know how to do this and also re-tensioning procedure ?
 
its a self adjusting belt. you will see just to the right of the compressor there is a small pully (tension pulley)
just to the right of that and in a bit is a female torx head screw. with a socket, extension bar and ratchet turn clockwise and the assembly will move, take the belt off. go careful as you release as it may snatch back and do your knuckles
 
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In my opinion the benefits of slackening belts for the winter are academic. My belts on my KAD43's are now nearly 7 years old and ok for a while more I reckon.

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Eeek!
That's a bit of a long time, imho. The belt ribs do get thinner with use.
 
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In my opinion the benefits of slackening belts for the winter are academic. My belts on my KAD43's are now nearly 7 years old and ok for a while more I reckon.

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Eeek!
That's a bit of a long time, imho. The belt ribs do get thinner with use.

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Yeh, but we're talking less than 400 hours. I've still got the same belts on my Shogun from new and thats done nearly 100,000 miles
 
Thanks very much gingie. I know the small tensioner pulley you advise. Will now be able to sort.

Davidj, i always release tension on belts on previous AD31 engines during the winter lay up period so they do not take a set where they are in the same position for several months. Not a problemm if your boat is in constant use during winter IMHO. Maybe not a thing to do with the serpentine belts ?/forums/images/graemlins/ooo.gif
 
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In my opinion the benefits of slackening belts for the winter are academic. My belts on my KAD43's are now nearly 7 years old and ok for a while more I reckon.

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Eeek!
That's a bit of a long time, imho. The belt ribs do get thinner with use.

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Yeh, but we're talking less than 400 hours. I've still got the same belts on my Shogun from new and thats done nearly 100,000 miles

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and if it's a 3.2 DID powered shogon, it won't need to be changed, because it's chain driven. on most engines with rubber toothed cam belts they normally go on mileage covered anything between 50k- 80k depending on manufacturer or in the case of low mileage a 5 year time period. IMHO 7 years is a long time, but hey they're not my engines! /forums/images/graemlins/grin.gif
 
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In my opinion the benefits of slackening belts for the winter are academic. My belts on my KAD43's are now nearly 7 years old and ok for a while more I reckon.

[/ QUOTE ]

Eeek!
That's a bit of a long time, imho. The belt ribs do get thinner with use.

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Yeh, but we're talking less than 400 hours. I've still got the same belts on my Shogun from new and thats done nearly 100,000 miles

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and if it's a 3.2 DID powered shogon, it won't need to be changed, because it's chain driven. on most engines with rubber toothed cam belts they normally go on mileage covered anything between 50k- 80k depending on manufacturer or in the case of low mileage a 5 year time period. IMHO 7 years is a long time, but hey they're not my engines! /forums/images/graemlins/grin.gif

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Agree if we are talking cambelts, but I think we are talking exterior equipment drive belts (I could be wrong I don't know the D4 Volvo)
However you may have embarassed me into changing them this year /forums/images/graemlins/blush.gif
 
How on earth did this question became hi-jacked into a discussion over life of internally toothed cam belts????

PolyV and PolyW belts were invented by Dayco Corp of U.S.A. along with self tensioning idlers as a ZERO maintainence form of auxilluary drive. Although now widely copied, hence the patented PolyW, principals are identical.

However ZERO maintainence does no mean ZERO inspection. In marine applications Dayco require annual visual inspection of the belt. Things to look for are cracks and splits, glazing, peeling, greasy buildup and splitting or missing sections.

Likewise the Dayco self tensioning idler pulley requires examination for slackness or a worn bearing. The actual tensioner spring normally just fails, rather than go weak.

There is no maintainence proceedure required involving release of the belt tension when engine out of use.

Remember because these belts are a ZERO maintainence item they are significantly more expensive than horrible old V belts. Change out on a whim if you have to, but do not complain about the cost!
 
Boating applications with these belts have their own issues: infrequent use, salty atmosphere = rusty pulleys

The Supercharger belt isn't so critical: probably would last a few years.

The smaller aux drive one is, though. At the very least it should be inspected & compared to a new one once a season. I've had one where I could pull away the outer "v" with one finger: an earlier water leak had made the pulley a bit rusty, which chewed up the belt in a few weeks. The pulley was nice and shiney by the end, tho /forums/images/graemlins/smile.gif
 
Re: Digressing

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How on earth did this question became hi-jacked into a discussion over life of internally toothed cam belts????

There is no maintenance procedure required involving release of the belt tension when engine out of use.

Remember because these belts are a ZERO maintenance item . Change out on a whim if you have to, but do not complain about the cost!

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The illusion of zero maintenance causes all sorts of serious issues.....
an hour after a cruise a Skipper should check his oil, belts, header , raw water traps and pre filters.

While doing this he should notice , oil, diesel , gear box oil, ATF , drips from Raw water pumps in his bilges etc

leaving them to slop around his engine bay may cause early rotting of the belts, salt water spray to bearings, weekly use will hide many faults, but following winter layup the VP guy will service the engines, he has no way of knowing about the bearing flat spots.....

Idiot skipper heads out into the channel and looses an engine
Blames the VP guy, it was fine the last time out ( 6 months ago) it must be VP engineers fault.

Alternator replaced, next week belt tension bearings fails.....and it goes on all because he thought it was maintenance free

I agree with S28

Low maintenance belts need replacing on a frequent basis .
In my opinion 2-3 years depending on single/twin installation, unlike a car you can not sit and wait on the hard shoulder for the AA.

Hows that for digressing /forums/images/graemlins/wink.gif

As to chiboaters question

taking tension off will help prevent bearing flat spots on the tensioner and alternator.
turning the engine once a month will have the same effect to all bearings.
 
Re: Digressing

Sadly it is called progress.

Manufacturers responding to customer demand.

Self tensioning Polyvee belts were around in industrial applictions long before automotive, as they were too expensive.

Mains failure/back up genset, fire pumps, commercial marine, thousands of trouble free different applications often in a marine envioment.

Trouble free until couch engineer leasure boaters start inventing their own solutions to non existant problems evidenced by the fact that some do not understand the difference between a cam belt and an aux drive belt.

Lets wind the clock back and suffer the nausia of twin V belts with all their implications all over again.
 
I'm with you on this one. I check my belts annually, but I've yet to replace them (though for some reason I do have three full sets of spares). The easiest wear indicator for me is the amount of belt dust on the side of the fuel tank next to the pulley.
 
I found that on the KAD engines, the circulation (The one that goes from the crank to the pulley above which in turn drives everything else) doesn't last me more than a season because of the force put on it to turn everything. However the actual Supercharger belt, alt and power steering are like new - Regardless I change them all every season. Overkill maybe but at least I know they won't snap
 
Re: Digressing

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some do not understand the difference between a cam belt and an aux drive belt.

.

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One of the first cases I had to deal with,

Owner of valuable classic car (think Porsche 911 ?) asked a mechanic to take a link out of the trimming chain as trimming chains were expensive and his had over stretched.

Mechanic told him to stop being so stupid and it would not work.

Owner insisted on the mechanic taking a link out the chain.

The mechanic agreed just to prove a point.

Needless to say the engine was written off.

who's fault was it ?

The owners for insisting it was done even though he was told it would not work.

Or the mechanic for doing as he was told even though he knew it would not work ?
 
Re: Digressing

Daka

Now I understand totally, a legal eagle.

I will stick will stick with boring old engineers who create real things rather than those who pontificate over intangibles, and create nothing!
 
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