The Mitsubishi Pajero Owners Club®

[zr0121]

Hi all,

I have a 2006 plate 3.2 did 5 door lwb.

Earlier on in the year in January I had a whining and screeching noise coming from the engine when pressing the gas pedal, turned out to be a loose belt. Took it to my local mechanic who tightened it and it had been perfectly fine ever since.

. . . . . . Until last week, the noise came back louder than ever, took it back to my mechanic who took off the airbox & tightened the alternator belt and said because I have a dual battery system fitted it's causing too much strain on the alternator and the belt keeps stretching and won't be able to tighten it anymore so soon will knacker the alternator.

Is there anyone else who has had something similar to this?

Can having a dual battery system cause the alternator belt to keep getting loose and need tightening every 6 months?

Will it eventually knacker out the alternator?

What's your thoughts on this, any help would be appreciated . . . . . Thanks in advance

[Google]

[icehawk]

I brought these fan belts for my 2005 shogun and they work great no squealing or stretching,the problem with a lot of the belts that are listed for the shogun only have a width of 9.5mm so they don't ride on the shoulder of the belt like they should do they run on the very thin face side,this together with them being slimmer causes them to stretch and slip.these belts are 11.9 mm width  also brought te aircon belt that is 13mm width.
https://www.autodoc.co.uk/bosch/701311

[zr0121]

Thanks for the info   Will get these and give them a try see how I get on.

Thankyou

[assassin]

What twaddle, twin batteries will not cause the alternator to come loose, many belts stretch with time and mileage and neither destroy an alternator unless they are overtightened and this destroys the front bearing usually.

Alternators are designed to work simply by machine sensing the battery capacity and charging it at high outputs until it senses the battery is becoming charged and it lowers its charge accordingly.

One of my former expedition trucks had 4 batteries being charged from a standard Bosch K1 alternator, two were for the engine and the other 2 were spares, another K1 charged 3 huge batteries for the services and these remained charged for over a month without recharging.

When an alternator charges a battery it only replaces what is taken out, your model consumes about 600 amps for about 5 secondsso lets do the maths; 600 amps at 12 volts = 7200 watts if cranking for  1 minute and if you crank your vehicle for 5 seconds before it starts it is consuming 7200 divided by 20 which = 360 watts. If you have the standard alternator rated at 140 amps at 12 volts this provides 1680 watts of charging power per minute and this means it takes less than one minute to replace the consumed power to your batteries in less than 1 minute of running your engine.

[zr0121]

[assassin]

You're welcome, Icehawk hit the nail on the head, belts are designed to drive on the tapered edges and not the flat bottom or partial sides, the belts are indeed 11.9mm wideand standard belts are 9.5mm wide and a different taper angle which gives two immediate problems.

1) the 9.5mm belt sits much lower in the pulleys and isn't correctly driving on the full tapered edges as they should.

2) being lower in the pulleys means they bottom out and partially drive on the tapered sides and also on the flat bottom of the pulley.

Other issues arrive with modern belts and that is they are often designed to be used with an automatic tensioner system and they are usually spring loaded idler rollers, when the belts are running any tension is applied by the tensioner and this also takes up any slack so the belts don't need to be manufactured to such high quality, this means that most modern belts are built to stretch and do so with the knowledge that the automatic tensioner will take up any slack, they are also softer as this gives more grip, particularly in winter with ice and damp air make the pulleys slippery.

Therefore, you need a belt suitable for your system, it needs to be the correct width, it needs to be non stretch and you need to balance the tension when you fit the two new belts together and tension hem so one is slightly too tight and the other sloghtly too loose, you run the vehicle and let them stretch as this stretches the tighter belt and allows the looser belt to attain the correct tension, then tension them again. Gates and Bosch do the correct belts which are the correct width and are non stretch so I prefer these as they are not much more expensive and my last ones were fitted and run in, correctly tensioned again after 500 miles and never moved, they were on the vehicle for 6 years.