Fan/alternator belt keeps slipping off 304 v8 (VN)

[seabs]

Hi guys,

Few months ago my alternator died, so mech. replaced it.

Then a day or 2 later the car over heated, checked, and the alternator /fan belt belt had slipped off.

Took it back in to him, he put a new one on and I asked him to check that the tension was corect. he put new belt on and said it was fine.

Week later, same thing belt comes off, car over heats..

took it in again, they said my harmonic balancer was gone, fair enough as its a common problem, so they replaced that, then about a week later its spat off the belt again!

On the alternator, can you adjust it back and forth? (i.e more towards the back of the car, or more towards the front?)

Cos i have a feeeling the pulleys are slightly out of line.

Any ideas??

[5ivespeed]

gilmer drive

[seabs]

yeah i was thinking about that option.

Is it difficult/possible to retain the clutch fan with gilmer drives?

cos i'd either go the twin AU thermos, or gilmers, cant afford both atm.

[immortality]

either they supplied the wrong alternator (different offset) or maybe ballancer isn't all the way on the crankshaft

[VT-565]

Take the belt off and have a look at the alignment of your pulleys. You may be able to shim the alternator, I don't think the balancer is the problem, as this has all happened since your alternator was replaced.
Even a gilmer drive has to have good angular alignment, although it can take some parallel misalignment.

[krawczuk]

Hi guys,

Few months ago my alternator died, so mech. replaced it.

Then a day or 2 later the car over heated, checked, and the alternator /fan belt belt had slipped off.

Took it back in to him, he put a new one on and I asked him to check that the tension was corect. he put new belt on and said it was fine.

Week later, same thing belt comes off, car over heats..

took it in again, they said my harmonic balancer was gone, fair enough as its a common problem, so they replaced that, then about a week later its spat off the belt again!

On the alternator, can you adjust it back and forth? (i.e more towards the back of the car, or more towards the front?)

Cos i have a feeeling the pulleys are slightly out of line.

Any ideas??

wouldnt suprise me if they are bosch belts , get some gates belts..
mark k

[wez]

Could it be as simple as belt not threaded correctly? Worth a double check.

[seabs]

Take the belt off and have a look at the alignment of your pulleys. You may be able to shim the alternator, I don't think the balancer is the problem, as this has all happened since your alternator was replaced.
Even a gilmer drive has to have good angular alignment, although it can take some parallel misalignment.

yeah, i've had a look at the alignment, and to my eye i reckon the alternator pulley is sitting just slightly forward of the other pulleys, not sure but i think they may have shimmed it too much?

either they supplied the wrong alternator (different offset) or maybe ballancer isn't all the way on the crankshaft

Thats a possibility, also, its not a genuine bosch alt.

And wez, its thrown 3 different belts, so it's something out of line or something along that path i think.

[VrWagz1]

Maybe they've supplied a different alternator, maybe somthing they had laying around the workshop and they just changed the pulley wheel on it. If its out of alignment, there is somthing wrong there. You either need a new proper fitting alternator or they have somhow butchered the alternators mounting brackets. At worst i would try another alternator, do you have a mate with the same car you can try.

[VT-565]

yeah, i've had a look at the alignment, and to my eye i reckon the alternator pulley is sitting just slightly forward of the other pulleys, not sure but i think they may have shimmed it too much?

Alternator should bolt in behind the bracket, you should be able to shim it back to get good alignment. Run a piece of string through the pulleys to help you line it up by eye.

[seabs]

Maybe they've supplied a different alternator, maybe somthing they had laying around the workshop and they just changed the pulley wheel on it. If its out of alignment, there is somthing wrong there. You either need a new proper fitting alternator or they have somhow butchered the alternators mounting brackets. At worst i would try another alternator, do you have a mate with the same car you can try.

yeah thats a possibility hey, mate used to have a 5L but he upgraded to vu ss, ex missus has a 5L but don't wanna go near her lol.

I might try get some serial / model numbers off the alternator thats in there and see if it is a correct fit for my car, or if they've dodgied it up like you said they might have.

[seabs]

Alternator should bolt in behind the bracket, you should be able to shim it back to get good alignment. Run a piece of string through the pulleys to help you line it up by eye.

fu<k yeah! i didn't think of shimming it that way, it only looks too far forward by maybe 2mm or so, but when revving hard.. that will most likely make a considerable difference.

cheers by the way!