1973 PTO Belt Questions

A few things spring to mind here: firstly looking for bearing play is best done with the lever set to depress the centre button of the front PTO, i.e in the disengaged position. I'm seeing your mechanic friend looking for play with the springs in the engaged position, the tension of the springs, as I'm seeing it would take up any bearing slop by the spring tension. Once assessed BEFORE you ever try and remove that front PTO there are a dozen small but critical tricks to read all about in the FAQ section. Settle down with several cups of tea/coffee (etc) and read those pertinent FAQ's thoroughly.

Then, on my 100 BOTH the lower mule drive front pulleys are on the INSIDE of the hanging adjustable bar, your one good one is on the OUTSIDE of that hanger tensioning bar from what I can see. Belt size is a function of pully diameters in the train,.... and with a slightly larger diameter idler pullies on that tensioner,... an 80"belt may be the reason you are pondering. On mine the belt lines coming from the PTO form near vertical AND parallel lines so that a full 50% of the Pto drive circumference is in contact with that drive belt if not fractionally over that 50%. If im correct with the one pully on the outside your contact drive surface will be less than 50% of the circumference..... and a smoke generator.

call Digger to ask him to measure Original pulleys diameter and describe how he determined that diameter so you do it the same way (i.e: total outside diameter or contact surface position diameter)

Hunt the grass for that pully, for two good reasons, you dont want to Mow it up next cut, its not great for the blades and it becomes a leg/window/head breaking missile if that big blade finds it......
cheers oupa G

2 schools of thought here...if the clutch holds, is not missing pieces, and does not have more than 1 or 2 of the 'fingers' broke off of the friction disc, you can replace the bearing and keep running it. Verify dimensions, but a Fafnir/Timken RA100RR bearing crosses to the bearing in your first link. Beware of high markups on cheap bearings from most selling it by the IH part number- the exact bearing in your link is available for $10-15 all over under the industry standard part number etched into the race. I would order the bearing from a bearing supplier so you know what you are getting.

If it were mine I would rebuild the clutch while it is apart. The rebuild kit (part number 759-3489) will be cheaper than the entire rebuilt clutch you linked to.

Drop the deck and remove the mule drive and inspect everything.
Remove the grill so you can get at the PTO basket pulley and bearing.
This is not rocket science!
You are not going to be able to discern anything by messing around the way you are doing.
You need to remove the bearing and spin it in your hands to get to the bottom of this.
It looks like someone has had their way with a welder in there on that left side idler support, part #17
Both these supports, #'s17 & 5, should rotate freely on the mounting rod (part #6Y
The belts are adjusted with a nut and washer on part #3, until the pullies are basically in line with one another.
Good Luck!

dschwandt said:

Drop the deck and remove the mule drive and inspect everything.
Remove the grill so you can get at the PTO basket pulley and bearing.
This is not rocket science!
You are not going to be able to discern anything by messing around the way you are doing.
You need to remove the bearing and spin it in your hands to get to the bottom of this.
It looks like someone has had their way with a welder in there on that left side idler support, part #17
Both these supports, #'s17 & 5, should rotate freely on the mounting rod (part #6Y
The belts are adjusted with a nut and washer on part #3, until the pullies are basically in line with one another.
Good Luck!

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Thanks everyone!! I have a lot of homework to do!!

As for the position of the drive pulley's, I have watched numerous videos of 149 and 129 tractors, and all of their drive pulley's are aligned like mine. The left one (passenger) sitting outside the bracket and the right one (driver side) sitting on the inside. And mine has had some weird welding hacks over the years but prior to the pulley falling off, it worked great.

I did go back and checked the video of when I purchased it on June 13th and the pulley that fell off was in fact on their when I brought it home. I also checked the video for the alignment of the pulleys to the belt and everything was nice and straight and lined up when the pulley was in tact. I did find out the left side (passenger) pulley is seized up as well, so with both failing and one falling off, it was a disaster waiting to happen!

And for the record, I did see if there was any bearing with the PTO engaged and disengaged, but as the one user said, I have to remove it to really get a good look.

Ok, now it's time for my son and I to comb the yard for that pulley! It's a John Deere, but i'll let it slide

149CubLover said:

Here's a video I took for a mechanic friend. Shows me looking for excessive play in the bearing.

Click to expand...

That PTO needs rebuilt, your not supposed to be able to turn it like that. Replace the non existent pulley before you do anything. Then check the manual on how to adjust things like Matt posted.

After installing the new drive pulley's and adjusting the left side to 3 1/2" per the manual, everything looks great.

There is no wobble in the clutch. Everything is aligned and running evenly. I cut some pretty thick grass at the lowest cut possible and it ran great. No belt smoking and or slipping.

After combining the yard with my wife and son, we found the blown out pulley. That puppy failed hard! But the left side was seized as well so I'm not surprised something failed. The left one wasn't too far off.