451 Belt Change

The 451 turbo and non turbo (before the MHD bullshit arrived) had the same belt arrangement. The belt (shown below in red) was driven by the crank pulley and that turned the water pump and the alternator.

Obviously you want the water pump to spin so fitting a new belt before every 56,000 miles is a great idea. Loosen the offside rear wheel, jack up the car and remove the wheel.

Look behind the suspension components and you’ll see 2 large plastic push clips.

It’s like a top hat pushed into a cats bum.

Lever the top hat part out…

…and the rest of the clip should come out on the end of it.

The belt cover will then drop down and scare you.

Wiggle it, just a little bit (2 in a room) and drop the plastic cover out of the way.

The arrow below is pointing to the belt tensioner.

It’s a fairly standard design. It hinges at the large end with the bolt. The narrow end is the belt pulley.

You need to make a special tool. A piece of bar stock steel that won’t bend is ideal. Drill an 8mm hole and weld in an 8mm bolt.

I didn’t have that.

I had box section aluminium. I drilled an 8mm hole all the way through and then opened the hole out enough so the bolt head could be smashed in with a hammer.

The distance from the bolt to the end of the lever can’t be any longer than 31cm or it’ll hit the track rod.

Put the protruding bolt into the hole at the narrow end of the tensioner…

…and rest the tool securely under the bolt head. Push the lever upwards and this will push the tension downwards.

On top of the tensioner you will 3 raised sections.

When you move the tensioner with the lever, 2 raised sections on the tensioner pass the 1 raised section on the engine. Once you have moved the tensioner enough with the lever, you can place a 3mm allen key in to lock the position.

Another video, I’m becoming Stanley Kubrick with all these movies.

Once the tensioner is locked open, you can remove the tool and the tensioner will stay in position. The belt is now loose enough to manually remove it from the crank pulley.

If you look into the top of the engine you can see the the other pulleys.

The belt can be freed from all of the pulleys and removed. When you fit the new belt, make sure it lines up centrally with all of the 3 main pulleys before you use the tool to remove the 3mm allen key which will tension the belt.

Replace the belt cover and refit the wheel.

Belt Part Numbers

Go to a smart dealer and order:

Alternator & Water Pump Belt – A 0019934496
Air Conditioning Belt – A 0019934596

Tool Part Number

Although I made me de-tensioning tool, smart do have a part number for the one they use. Be aware though that some dealers won’t sell smart tools to the public.

A451 589 00 10 00

3mm? I Live In America

Grab a 1/8″ allen key and that should fit in the retainer just as well.