Hi Guys

I'm gradually working my way round the front end of the car, basically doing all the jobs you put off, (in reality opening cans of worms). But after replacing the front suspension noticing the chassis was looking very tatty I decided it needs renovating along with other bits and pieces that have started to accumulate surface rust. One of the jobs I've been planning since getting the car is replacing the ancillary drive pulley on the crank as the vibration noise is becoming embarrassing now and I've been meaning to do it for a while but always got side tracked. As I'm taking the suspension apart I'm thinking its an ideal opportunity to replace the pulley at the same time when I've got it all stripped out, and in theory should have easier access to the pulleys and drive belts, I've also got the front bumper off as I've rebuilt the front cross member radiator support bracket and had to drill out and re tap all the bolt housings as they were rotted solid in place. it also gave me access to the front chassis to grind off the rot and get a new coat of under seal on. But here's the question for you guys, I can see from running the engine with the front end stripped out the crank pulley vibrating that definitely needs replacing but I've read on other forums there is a fault with the alternator pulley that causes the wobble in the first place, and there are also aftermarket engineering cos that make an alternate pulley for the engine to stop it happening again. I've seen there's a number of replacement kits for changing the pulley that include all the ancillary drive pulleys but are not sure if I need to replace all or just the main crank and belt. The tensioner pulley looks an absolute mare to get out so if I don't need to do it id rather not, guess I'm looking for what the recommended approach is and what happens if I don't change everything....

 

Ive managed to source a complete set on ebay including the tensioner, has anybody replaced just the crack pulley to quieten, and did you have to replace the tensioner also after?

 

Hex,
Firstly, as the belt is long, and as the alternator armature runs at 2.7x speed of the crankshaft, their is an inherent slap in the belt.
This causes the tensioner to oscillate, so wearing the tensioners bushes to get worn.
Also the crankshaft speed pulses on the firing strokes, so the crank pulley has a rubber bonded between the inner part and the outer ring that has the grooves for the belt.
This rubber starts to unbond, causing the pulley to become loose and unbalanced, further causing accelerated belt slap and tensioner wear.
If you intend keeping the car, you are wasting money by buying an aftermarket replacement kit, as this won't last, and the build quality is inferior.

The upgraded jag kit consists of a "upgraded" crank pulley, that is wider than the original, the pulley is actually from the mk6 transit !
On top of all this, if you fit an over running alternator pulley, you will also further reduce belt oscillation, so extending the life further.

I have fitted the over running alternator pulley, as well as the uprated crank pulley, and it is smooth as can be.

Paul.

 

Hi Paul
Thanks for your advice, did you replace the tensioner when you changed the crank? Also did you have to get the upgraded crank and alternator pulley separately? I'm probably going to keep the car for between 3-5 years now give or take how we come out of the current economic / health situation. I originally wanted to keep it until electric cars were firmly established but again not sure how that's going to pan out. Would I be right in saying that even if I replace both pulleys and reduce the noise its going to happen again over the course of 30/40K mls?

 

Hex,
Yes I did replace the tensioner when I replaced the crank pulley.
I managed to source the crank pulley, tensioner and inner wheel arch cover separately.

The upgraded crank pulley is BK2Q-6B319-BA, this has to be a genuine ford part, not other.
The inner arch cover is part no. C2S49622

If you want to buy the complete jag upgrade kit, the part number is C2S51547, and will cost north of £300+
The jag kit consists of the crank pulley, 3 pulley bolts, the tensioner, the inner arch cover and a new belt.

Regarding the over running alternator pulley (part no INA 535022310), this is a worth while modification, and will extend the other parts life, and reduce noise further.

The alternator will need the old pulley to be removed, a alloy casting ring cut, and the new pulley fitted with the supplied 3mm shim.
The pulley acts as a one way clutch, so allows the alternator to free wheel when required.

Paul.

 

Hi Paul

I think Ill go for the alternator pulley upgrade, but wanted to sound you out on the crank. I hear what you're saying re genuine ford part, and thinking given the age of the vehicles now are these likely to be available elsewhere? Also is the vibration likely to come back again in say another 40k miles after I've replaced these parts?

I noticed on the likes of ebay there are a lot of sellers offering the upgraded pulley, with varying prices but I also recognise what they say and actually do can be very different things. I've struggled to find the price for the ford part as the virus has caused main dealer spares deps to be closed, so I've had to use third party suppliers for jobs that I've been doing, or fabricated parts myself. How many miles has your vehicle done since changing and is it still quiet?