Club G40 Forum

Technical => Engine and Transmission => Topic started by: spookey on January 21, 2012, 12:56:38 PM

Title: Top alternator mounting bolt keeps breaking!?
Post by: spookey on January 21, 2012, 12:56:38 PM
Hi guys this problem has happened twice on me in about a year of the car being on the road.

The car has P.s.d toothed pulleys, I believe they are the ones that juan had manufactured previous owner was rfkdeamon on here if any one has any info?
and it has a adj bottom alternator tension from a standard mk3 polo.
now when i was trying to adjust the charger last it always seemed to run out of adjustment ie was always on the max even with a new belt on. could it be the pulleys??

does any one no the problem? the cars in bits atm so if anything needs replacing it would be easiest when the engines out.

Thanks Luke


 
Title: Re: Top alternator mounting bolt keeps breaking!?
Post by: ereeiz on January 22, 2012, 12:38:44 PM
The toothed pulleys seem to cause the alternator to max out on the adjuster. Mines got a couple of mm at most. I don't know if anyone's created a bolt on automatic tensioner for it (like you'd get on most cambelt set-ups) but that'd be a great idea if someone were to do it!
Title: Re: Top alternator mounting bolt keeps breaking!?
Post by: ereeiz on January 22, 2012, 12:42:25 PM
As for the snapping bolts, not sure what the standard bolts rating is, but if it's just some cheapo 8.8 mild steel things then that could be the cause? If they're proper bolts and they snap, perhaps you're over tightening them? If they're done up correctly then I'd start looking at things being out of line so it has a funny load on the brackets/ bolts. I've a few other ideas but they're just ideas so not sure if they're even relevant!
Title: Re: Top alternator mounting bolt keeps breaking!?
Post by: spookey on January 22, 2012, 05:13:51 PM
Cheers for that ereeiz. I dont think any one has done a auto-tensioner but one of those on the mk3 era engines are bill would never bolt on tho!!

Well the first time it happened was when i was driving it down to Plymouth a couple of months after i brought the car the bolt broke on me on the way down letting the alternator to fall off so not unless the previous owner over tightened it before i got it.   

The 2nd time i brought a gen used bolt and a gen spacer off a guy on here (all 2nd hand mind). Now it was a while ago i did this but i believe i torqued it up properly. I know there was some jiggery pokery to get the bolt in i think but nothing major. but like i say it was a long time ago.

I was thinking about trying to source a high tensile bolt from somewhere but as every one else use the normal bolts why cant i? I know the 2nd bolt broke on the threads inside the mount but thats all i know  ???

Title: Re: Top alternator mounting bolt keeps breaking!?
Post by: Jezza-7 on January 22, 2012, 07:27:30 PM
Do you live im plymouth?

How tight are your charger belts?
Title: Re: Top alternator mounting bolt keeps breaking!?
Post by: spookey on January 22, 2012, 10:23:03 PM
No jezza i live in salisbury i was on my way down to Plymouth for a vw show.

Urm well the g is in bits atm but when it was all togher i dont think i over tightend the belt.
like i say the charger was preety much at full adj because of the toothed belts apparantly. so i dont think it could have over tightened the belt if i wanted to!
Title: Re: Top alternator mounting bolt keeps breaking!?
Post by: Jezza-7 on January 22, 2012, 11:05:24 PM
Ok well im only down the road. Live in yeovil so if your around at weekends i could always pop up. You buy joe k's shell? I got an old alternator with all the original bolts your more than welcome to try, although its on ebay, but im sure i can lend it for a week. If that breaks then there has got to be something more serious that snaps them.
Title: Re: Top alternator mounting bolt keeps breaking!?
Post by: spookey on January 23, 2012, 05:24:36 PM
Ow cool always nice to find some one local. No that wasn't me. was it a grey one tho? from Andover?

Ive still got my original alternator (thankfully my subframe caught it!) but would be interested in the original fittings if your willing to split?

sadly i need to get my shell back from the body shop before i can try all this lot out but thanks for the gesture.