help diagnose my Hustler CVT issue

[micmac]

I'm having an issue with my CVT system and I'd thought I'd throw it out there to find a solution.


Here is a history of what's going on:

I current belt is 46 1/4 and 1.23 inches it's an old belt and I assume it was originally 1.25. I ordered a Dayco HPX 5001 belt as it fit the specs and was a High performance belt. I put it on the machine and ran it for a couple minutes and turned the machine off and found this:



So I checked my old belt and it matched the size. The tension is not that tight. I installed the belt without much difficulty by walking it over the driven.
The only issue I have with the old belt is an oscillation at about 3/4 power:

I'm at a loss and don't want to replace the replacement until I figure it out. I do have a custom engine mount that may need adjusting.

Any insights or suggestions would be much appreciated.

Thanks

Mike

[whipper-ag]

Can't tell from the video, but 1st check your rubber engine mounts. Make sure they are not letting the motor "twist". Are both clutches set up for 1 1/4" belt?

Whipper

[jpswift1]

Hey Mike, check both pulley faces to make sure there aren't any ridges or grooves worn into them. Do you know if the belt recommended by Hustler was 1 3/16" or 1 1/4"? I don't know for sure, but just throwing a couple of ideas out there.

[micmac]

Can't tell from the video, but 1st check your rubber engine mounts. Make sure they are not letting the motor "twist". Are both clutches set up for 1 1/4" belt?

Whipper

Whipper I used poly swaybar bushings for mounts it seems pretty secure and the engine doesn't seem to twist under load.

Is there a way to measure the clutches to determine the proper width belt it takes? With this old of machine there is no telling whats been swapped out.

Hey Mike, check both pulley faces to make sure there aren't any ridges or grooves worn into them. Do you know if the belt recommended by Hustler was 1 3/16" or 1 1/4"? I don't know for sure, but just throwing a couple of ideas out there.

Jeff the driven does have a slight rough groove at the bottom I'm going to see if I can polish it with some emery cloth today. From what I've seen on the board the hustler belts were all 1.25 and were 46.5 in long. I'm going to get a longer belt as recomended by Don (The Man) and see if that works. What I'm confused about is that the belt seems to be loose enough when static

[jerseybigfoot]

The belt looks like it was in a grinder. If you have just belt dust from the failure check the drive cvt shaft for cuts from a pipe wrench. That with a new tight belt will give just dust. If you have belt teeth that came off you probably have a defective belt

[micmac]

The belt looks like it was in a grinder. If you have just belt dust from the failure check the drive cvt shaft for cuts from a pipe wrench. That with a new tight belt will give just dust. If you have belt teeth that came off you probably have a defective belt

Marc,

I did have belt teeth come off so I'm hoping that it was just a defective belt. I looked at the Drive clutch and ran the engine at idle and had a paint stick with emery cloth taped to the end. I finished it off with steel wool so everything looks smooth. What do you think about the belt vibration in the video? do you think something is out of alignment?

Mike

[jerseybigfoot]

I looked at the vid a few times and it looks like the belt is out of alignment or bending when its vibrating. The engine should be moved outboard a little bit.

[jerseybigfoot]

Blackbird cvt under load and at speed.

[micmac]

Marc,

By outboard do you mean outword toward the left side of the machine?

Thanks for all the input guys this is great info

Mike

[micmac]

Here is what the alignment looks like

[Roger S]

Looking at the video, I thought the same as Marc.

Looking at the last alignment pic, though, it looks like the crankshaft and t20 shaft aren't parallel, they are leaned in toward each other... one or the other. Also looks like the drive clutch is inboard a little.

What do you guys see?

[micmac]

Roger,

I see what you're talking about. I can easily adjust my motor mount to twist a bit backward. That may take up some of the inboard and help with the issue. I give that a try tomorrow. I don't really have an easy solution to move it more outboard looks like a weld/fill and redrill session may be in my future

Mike

[brushcutter]

Before you go moving stuff around, look at the input shaft on your transmission, you will notice that it is walking in and out. this is causing the wobble in your belt.

[micmac]

Brushcutter,

There is about 1/4 inch play in the driven in and out. My Max IV has no play but I thought I read somewhere that the older t-20 this was normal so I didn't question it. Could be the problem?

[brushcutter]

In your video, you will notice the driven pulley moving in/out every time the belt wobbles, Mine moves a little bit, maybe 1/8", but I have never measured to see exactly how much.