Cathy, it's the motor belt. The motor belts on these older models have cleats. I think the timing belt also has cleats(fewer I believe), but I'd have to double check that. It was my fault it broke. I put too much pressure on a 50 year old belt. At least the motor is nice and clean now.....sigh. Live and learn.

Will you post a picture so that those of us can see and learn what this belt looks like? And where it goes on the motor.

Sure. I borrowed this picture from the net. It's not my machine. Mine is now deep in the attic since I can't use it. The 73 cleat double belt on the left is for the timing. The single 84 cleat belt to the motor goes on the far right. But I think in the photo the belt is missing. But, you can see all the grooves for where the cleats fit in. The single, 84 cleat belt is the one I broke. The belt pictured is similar to the one I need.

The belt attaches to the motor and pulley here.

I wonder if a belt off a Kenmore would work - might be cheaper to find a Kenmore parts machine than a Pfaff.

the machine i didn't buy
 

Just found a Singer industrial, been on my want list for a while. Good price, too. However, today is my 19th wedding anniversary, and I somehow thought that my DH would not want to spend a rainy afternoon figuring out how to get the beast home, and then where in the house to shoehorn it. So, basically his anniversary gift is me NOT buying a huge machine.

I did buy a smaller one, though, a bit of an oddball. Has the name "sewmaster" which seems like a pretty common badge name. What's odd about it is it was made in Czechoslovakia. Not somewhere I'd expect anyone to import a machine from! It's cooling its heels in the trunk until AFTER tonight's romantic dinner....:o

I picked up a Cinderella sewing machine on my wonderings yesterday. It is in a smelly, miserable, little case. It is missing the slide plate for the bobbin and motor belt. The machine is very small, light weight - seems to be a couple pieces of metal put together. The nose, bobbin and throat plate seems to be the same as a Japanese 15 clone - it is smaller than 3/4 size. I need to take it to the shop and clean it up. I've been full speed working or dealing with some very serious family issues of late. Keep us in your prayers, it ain't over until the fat lady sings.

What type of Kenmore belts are you thinking about Miriam that have cleats? I didn't know Kemore had belts like that? I do know there is someone remaking the Pfaff belts using broken ones and the cleats. But, again, too expensive for a machine that's not worth sinking the money into.

too bad I sold that one I had - it went cheap too - could barely get rid of it.... I have no idea what model it was - old green minimal machine - belt like you are saying - I'll keep an eye open though.

Yup, sounds like this machine:> Minimal and not really in demand! Thanks, I appreciate it! Hope things work out o.k. for you!