Photo Essay - Replacing Ba & Bf Engine Pulleys

[PhilMeUp]

A rattling or whining sound from the engine bay could be originating from worn bearings in a couple of the engine pulleys - the idle pulley or the tension arm pulley.

A noise that sounds extremely expensive could be as simple as just a worn bearing in either of the idle pulley or tension pulley.

My taxi was making whining noises from the engine bay all weekend, which I figured was from one of these pulleys.

Replacing these two pulleys is easy and cheap to do.

This is the engine bay on my taxi. It looks quite clean, considering that it’s done 489,000km. All I do is give it a spray with CT18 every few months and rinse it out with a garden hose.

Because this car is dedicated LPG there is an air pipe to remove first.

Then I removed the airbox snorkel.

The thermo fan is held in place by one bolt on each side. Each bolt has a 10mm head.

I also disconnected the power cable for the thermo fan.

A 10mm ratchet spanner removes each bolt in a few seconds. There isn’t room for a ratchet and a normal spanner is slow and cumbersome.

BA Falcons had two hoses running from the coolant tank - one overflow and one routing back the thermostat cover. My BFIII didn’t have the hose to the thermostat cover so I bought the thermostat cover, hose and two-outlet coolant tank. This helps to ensure no air locks in the cooling system. The hose to the thermostat is held in place by the upper plastic of the thermo fan.

My BFIII has had the standard heat exchanger removed and an external transmission cooler kit fitted. This places a radiator-like cooler at the front of the car. Instead of using rubber hoses my car has aluminium pipes from a BA Falcon as these are sturdier.

Once the two bolts are removed and the power cable disconnected the thermo fan lifts out with a big of jiggling from side to side to get the sides of it past the radiator hoses. This leaves a suitable gap between the engine and radiator.

To remove the belt the tension arm needs to be rotated - there is a 3/8” square hole in the tension arm for this. I don’t use a 3/8” ratchet so I used my normal 1/2” ratchet with a 1/2” to 3/8” adaptor.

Lifting the ratchet upward rotated the tension arm, allowing me to remove the drive belt from the top two pulleys (power steering and idle pulleys).

On BA Falcons Ford put a sticker underneath the bonnet which had a diagram of the belt routing. Later Falcons (including mine) didn’t come with this decal, so I bought one and put it in place months ago so that I would have the diagram handy when required. The part number for the decal is BAF9C485A and it retails for $6.32.

For removing the pulley bolts I used a six-sided socket to ensure that there was no chance of rounding off the bolt heads.

I then removed the idle pulley.

The front of the engine after I removed the idle pulley.

Part numbers:

Idle Pulley: BA8A617A (This includes a new bolt, internal plastic spacer and front washer)

Retail Price: $33.55

Drive Belt: SX8620A

Retail Price: $54.70

Tensioner Arm and Pulley: BA6B209A (This is for the pulley and complete tension arm)

Retail Price: $130.00

Total to replace the idle pulley and tension pulley/arm: $163.55

However, this can be done a bit cheaper. The bolt, plastic spacer and washer for the idle pulley don’t need to be replaced, and the pulley is the same as what was used on the EL and EF Falcon.

The tension arm also doesn’t need to be replaced. The pulley on it is also from the EL and EF Falcon.

Idle Pulley - EL & EF Falcon: EF6T217A

Retail Price: $23.35

Tensioner Pulley - EL & EF Falcon: EF6B217A

Retail Price: $26.25

Total for the two pulleys: $49.60

I then removed the bolt that holds the tension arm in place.

You can see in this photo the 3/8” hole that is used to rotate the tension arm and loosen the drive belt.

The other side of the tension arm. The pulley is attached by a bolt with a 13mm head.

I held the tension arm against the ground with one hand and loosened the bolt with a ratchet in the other hand. I also used a six-sided socket for this bolt.

[PhilMeUp]

The pulley after it was removed from the tension arm.

I put a finger through the bearing and rotated the pulley. I could feel movement in the bearing, indicating that it was worn.

I then put put the new pulley on the tension arm. I also added a drop of Loctite 222 (ie mild) to the bolt.

Re-routing the belt back into place can get fiddly, so I was careful to leave it in place when I removed the tension arm.

There is a metal lump on the tension arm that goes into an indent in the front of the engine block.

Where the bump on the tension arm goes.

Because I had kept the belt in place, I was able to fit the tension arm back into place without having to re-route the belt.

Then it was time to put the belt over the top two pulleys (steering pump and idle pulleys).

When putting the belt back on make sure that it fits properly into the ribs on each pulley. Once everything was confirmed in place I ran the engine for a few seconds before starting with putting the thermo fan back in.

Once the belt was back in place I had a look around before putting the thermo fan back in. There was a bit of grime around the connection for one of the transmission fluid pipes.

I used my high pressure water sprayer to clean up the transmission fluid connection.

If you’re ever doing anything in the engine bay of a BA or BF Falcon then check the area around the steering pump. There is an o-ring in the top of the steering hose that can fail, resulting in power steering fluid leaking out.

The problem with power steering fluid leaking is that it drops down on to the alternator. This will eventually wreck the alternator, which is not cheap to replace. This is why I check this periodically (eg when checking the engine oil level).

There is a mount on each side of the radiator that the thermo fan mounts on to.

The part on each side of the thermo fan that slides over the mounts.

The top of the thermo fan holds the hose in place.

People often forget to reconnect the power cable for the thermo fan. I’ve done it. Mechanics do it. I’m a lot more conscious about it these days, but write a note and put it on the steering wheel if you want to make sure that you don’t forget. Although the engine later running hotter than it should might be a bit of a hint.

I did the same job on another taxi of mine, but was frustrated to find that there was still a rattling sound after replacing the two pulleys. I eventually figured out that the tension arm was making the noise. I ended up grabbing another tension arm off a wreck, and that car is now rattle-noise-free. If you want to be cheap (like me) then just do the pulleys. If you want to be thorough then spend the extra money on a new tension arm as well.

[FiftyOne]

Another quality write up philly

[knowhereman]

Great write up! You could write TSB's for Ford.

[Bulletime]

I think one of these might be gone in my FG, as revs rise I get a strange whirring sound which I think is from around the pulleys. Best I can describe is it's similar to the sound of when my power steering has failed, possibly the idle pulley based on approximately where the noises are coming from.

At 135,000kms should I just do the tension arm as well? How can I be exactly sure it's the pulleys though?