Jump to content

Unofficial Home of Old Simplicity & Allis-Chalmers Garden Tractors

Sign in to follow this  

Mid PTO belt size

Recommended Posts


Just throwing this out there for discussion . . .

Last summer when I finished putting my 2012 LL back together, I tried the 1/2" x 35" mid pto belt called for by the manual. But, it was too long and I couldn't get the PTO to engage. So, I switched to a 34" belt, which worked fine. However, since it was the end of the summer I never hooked up the mower deck or any other attachments. Yesterday I put my mower deck on, and now the PTO will not disengage. It's looking like I'll have to switch back to the 35" belt.

This morning I was watching a Zippo video about installing decks, and he discussed having experienced the same problem years ago - a 35" belt is too long when no attachments are hooked up, but using a shorter belt won't work because when you put the deck on it stretches the spring tensioner coming off the tranny. (Wish I'd have seen this video before).

I've noticed that in several threads other members, such as Perry, indicate that they use a 34" belt even with the attachments on. I'm just curious, are you guys doing something to the tensioner spring to get the 34" belts to work, or is it just that you've never had the same experience as Zippo and I?

Share this post

Link to post
Share on other sites

I've learned only recently, that this belt is kinda model specific. Basically, as the model year gets 'newer', the belt needed gets shorter. The 35" would ahve been for early round hoods, the 34" for late ones, etc.

See if you can make heads or tales of this:


Share this post

Link to post
Share on other sites

I mix and match all the time, particularly because I have a wall full of belts and never the right size :o:O

You can use a shorter belt on the pto, but then you need a longer one from pto to deck, or a smaller pulley on the deck

Problem being, the further back the pto is (longer belt from deck to pto) the lower the pto is also, because it pivots front to back. With the pto lower, there is more chance of the belt rubbing on the deck cross bar.

Share this post

Link to post
Share on other sites

I think this is the video where Zippo describes the same problem I ran into; i.e., the recommended belt being too long unless you've got the deck on to stretch the spring:

I say I "think" this is the one because I watched a couple this morning, and I'm at work right now so I can't watch it again to make sure this is the right one.

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this  

  • Who's Online (See full list)

    • SmilinSam
    • wsherm
  • Today's Birthdays

    1. B-16_IC
      (46 years old)
    2. Flannelman
    3. Glen112
      (71 years old)
  • Recent Status Updates

    • Bubba1997


      Searching for a Sleeve hitch and breaking plow and other equipment if price is right and also a deck for a B1 thank you 
      · 3 replies
    • Dean McFadden

      Dean McFadden

      Good morning peeps! I’m always searching for helpful information with my AC collection. Hope to find out new information and pass on my own experience in restoration. Here are some pics of my babies. I’m still looking for front rims for the 410 so yesterday I put the 310 wheels on took it for a drive. Working pretty good but still needs some carb work. Gotta get the 310 running next. Have a great day!😁

      · 1 reply
  • Adverts