Belt Squeal

[lc 120]

Gents, I have a belt squeal in the morning which I would take to be a slack belt, all belts were replaced with genuine Toyota ones in August and have only done 3k since. Is there an adjustment screw that could fix this? the 2 x belts that are next to each other seem to be the loose ones...
Thanks

 

[BobMurphy]

The two identical belts that are close together drive the Alternator.

When you first start the truck the Alternator has to re-charge the battery, so puts a load onto the motor. If the belts are slack this is when they are most likely to slip. It can require 2+ bhp from the motor to spin the alternator when its charging at its full rate (120 Amps @ 12 Volts = 1,440 Watts = 1.9 HP + losses).

They are adjusted by moving the Alternator mounting. Slacken the pivot bolts a little and then use the tensioner underneath to alter the angle and tighten the belts.

It will be easier if you remove the steel sump guard and get at it from below .

Don't get them too tight, you should be able to move the belt up and down an inch or so and remember to tighten all bolts when you are finished.

Bob.

 

[lc 120]

Excellent, thanks Bob....

 

[tilly1]

remove belts and clean the pulleys , just had to do this on my 90 , also when i replaced the belt i put some belt slip on now silent ah bliss

 

[uHu]

I have tried different methods of getting to the adjuster on the alternator - as easy as poss. Ended up using the method of removing the air duct from the intercooler - faster, and convenient working position.

To lessen the strain on the alternator and battery, you can disconnect the intake heater. It's not required anyhow - just a environment issue in cold climates. Pull the little plug next to the heater relay. (it's been discussed here earlier)

Another thing is that the original belts are actually a bit narrow. There is a good quality replacement which is about a mm wider. I'll dig out the specs and post here. The length depends on whether you have the Power Heater or not.

Edit (belt specs):
I think the original is 9.5 mm wide, 1000 mm long.
Replacement:
Either ContiTech ZPX 1000, which is 10 mm wide
or another Conti (don't know the model) which is 11.9 mm wide, but then increase the lenght to 1013. Works like a charm.
For dual application, Conti sells belts in pairs, with exact same lenght, to prevent uneven/unbalanced load.

 

[l3n0x]

It's me again So I've replaced the alternator belts on my 1HD-FTE, and I don't know what the correct tension should be like. As per FSM:

But if I set it this way (align the belts so the printings are side-by-side), then start the car, run it for a minute and shut it off, the (Toyota) marks are not aligned anymore. So one (or both) of the belts have slipped.
Belts are brand new genuine Toyota belts, but it seems like the innter belt is more tight than the outer one. I can also see an ever so slight wiggle of the crank pulley (couple tenths of mm)

I don't want to over do it & have no experience in this, so any help would be appreciated!

 

[uHu]

...I don't want to over do it & have no experience in this, so any help would be appreciated!

You don't want to overthink it either. If it doesn't slip and squeal it's OK. Finished.
All belts slip a little -- Whoever said that they are obliged to slip at the same rate? Relax - it's W.E. now.

 

[PeterLC]

When belts slip the circumferential speeds of the pulleys are unequal. So they either slip both or none of them. Follow Uhu's advice.