1HDT Throwing fanbelts!

[crankycruiser]

My 1hdt keeps throwing belts!

Ive tried different brands, tried cleaning up all the pulleys, none of the pulleys have any damage, they all seem to be inline..

It seems the only time that it chucks them is when i start to drive "sprightly".......... AC belt is always the first to go..

Tonight i went for a bit of a hoon... i mean cruise... and it blew the AC Belt (brand new put on 3 days ago) as soon as I gave it a bootful up to around 3k in each gear till i got to the speed limit... or maybe a tad above....

So i took that belt off and have always figured that its been the ac belt coming off that has caused the other belts to come off... but once i got home after driving round for about an hr I checked and it had chucked the most forward main belt!!!!

This is starting to drive me nuts!

I had a new harmonic balancer put on it when they rebuilt the motor (20-30k ago), i pulled the bolt on part of the pulley off to check it out and its fine and they both doo look like brand new......

WTF is going on!??!?!?!

Surely the extra power wouldnt be causing this?? (its running a Gturbo @ 26psi)

[crankycruiser]

I just went and checked the crank bolt.. its all good. the ac idler pulley is a bit wobbly.. and has a lip on one of the sides in the V... i wouldnt say it was sharp.. but maybe enough i guess....??

[old ed]

If the air con belt idler is a "bit wobbly" as you put it then the bearing is well and truly finished. With a bearing that worn the idler cannot possibly run true, the uneven wear is evidence of that. Sort out that issue and see what happens then.

[Z()LTAN]

Not something silly like too much crank endfloat?

[hulsty]

Have you tried running it through the full rpm range slowly while watching the belts ? Might be able to notice any weird harmonic or crook bearing pop up. As above check crank end float, a mates 1HZ had MASSIVE end float.

[crankycruiser]

Thanks guys, got a genuine pulley to.put on this evening.

How do u check for end float ?

[Z()LTAN]

There are thrust washers around 1 or more of the crank journals. They can wear out or even fall out all together.

The action of the clutch pushes on the back of the crank shaft and tries to push it towards the front of the vehicle. Get a dial indicator if you can and a pry bar and see if the crank moves front to back. Pulling and pushing from the crank pulley. There is an acceptable movement.

[crankycruiser]

Put my new belts and pulley on a few days ago.. the AC idler pulley was sitting about 3mm proud of everything else... adjusted that with the angle grinder and things now seem a bit happier *fingers crossed*

[Z()LTAN]

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