I spoke to a Ford spare parts dealer today and they told me the AU serpentine belt is 20.8mm wide and the EF belt is 20.3mm. They both have six ribs, but the ribs go to the edge of both and therefore are not compatible.


A/C COMPRESSOR - I have been advised to run an EF a/c compressor on my AU motor because the EF compressor's tubing is more compatible with my EBII's tubing, but if as indicated by the dealer the EF a/c pulley doesn't suit an AU belt, there is a problem.

The dealer said judging from the pictures available to them it doesn't look possible to fit an AU pulley to an EF compressor, but they said they weren't certain of this.

If i use an AU compressor i would seemingly have to modify the tubing a fair bit, plus i would have to grind the mounting bracket back to allow space for the dizzy.


P/S PUMP - If as stated the belts are different and incompatible that also means all of the pulleys on the accessories are also incompatible. I was planning on using my EL p/s pump, but will have to fit an AU pulley or use a full AU pump.


Any help?

im sure you can use both.
in my case im using ef parts.
i know the power steer pumps are the same and water pumps are the same..

to be on the safe side i would use the ef/el belt..
if the ef belt is slightly narower it will still work as the gaps between the ribs are the same on the 6pk belts

Okay. I can at least check for myself my AU ribbed pulleys versus EL, using verniers. But if the belts are different widths with the same number of ribs going to the edges of the belts, i don't see how the gaps can be the same or in the same place.

Hmm, i was planning on using an EL p/s pump and EF a/c compressor, and an AU harmonic balancer, alternator and tensioner. From memory these are the only ribbed pulleys. The water pump has no ribbing.

Last edited by relaxed_diplomacy on Tue Sep 16, 2008 9:56 pm, edited 1 time in total.

if there is a difference i would say it would only be the outer edges of the belt.
but i doesnt hurt to measure the width of the pullies and see..

s**t yout talking 0.5 of as mm

thats f**k all for a belt

should work

That's what i reckon. But get the verniers out first.

I did some measurements today of the following:

EL grooved tensioner pulley
EL p/s pump
AU grooved tensioner pulley
AU harmonic balancer

First i measured the distance between the bottoms of the first and sixth pulley grooves. They were all the same.

Then i measured the width between where the belt would run. The tensioner pulleys and EL p/s pump were all the same, and the AU harmonic balancer was actually a bit narrower. There would be at least 1mm either side of an AU belt on the AU harmonic balancer, and as noted more on the other pulleys.

So my course of action appears to be to get an EF a/c compressor, measure it, then decide which belt to run. Unless it's narrower than the AU harmonic balancer it seems i would run an AU belt.

If anyone has an EF a/c compressor and cares to measure the width where the belt would run with verniers or the like it might help me out.

I went to ford today and learnt more about the belts. The EF and EL belts are the same, but have deeper and sharper ribs than the AU belt.

I was told all the idler/tensioner pulleys and p/s pulleys are the same, so the things to watch out for are the harmonic balancer, alternator and a/c compressor pulleys. The spare parts lady didn't say anything about the harmonic balancers or alternators, either she forgot or just doesn't know or they are the same as well.

Maybe i will get an a/c compressor and then check both belts.

I have noticed that automotive belts have over time been manufactured thinner, which reduces the effort required to flex them as they travel over the pulleys, reduces the amount of heat generated, and in that respect would act towards increasing the life of the belt. I have only noticed this with single v-belts, but i've only been using them. Maybe the AU belt is following this principle as well. If it could be retrofitted you would think ford would specify it, but they don't.