F3990 and 122 Hours

[AllDodge]

Have had the mower for about one year and I'm cutting and start seeing black soot over the left (non discharge) side of the mower deck. Its turning everything on the deck black.

I stop, remove the covers and don't see anything that might be rubbing the belts. Thought maybe it was a one time thing and I just didn't notice, so wiped a spot off. Short time later its black again.

Stop mowing and take it home. Wash everything off and remove covers. Remove enough tension off the spring so I can spin pulleys by hand, all spin easy. Disconnect drive shaft and I can turn the shaft easy. Check lube and its all good.

So I'm thinking, I need a new drive belt with only 122 hours because I don't see anything else that could be causing the soot on the deck

Thoughts?

 

[North Idaho Wolfman]

Pictures are worth a thousand words!

 

[AllDodge]

Pictures are worth a thousand words!

I acn get some pics tomorrow but I already cleaned up all the black soot. I can remove the covers and take a pic, but I don't see anything out of place, and when running the belt is smooth with only slight vibration.

Looking at the belt is not cutting, just sitting and watching

 

[AllDodge]

For me its a poorly designed belt. The belt id 2 V belts in one. When the belt wears to the point the center starts coming against the center of the two pulley's then the belt starts loosing adhesion.

This is the pics this morning before I started mowing, all cleaned up, and ready

 

[AllDodge]

As I cut more a start picking up speed here comes the black. Make it to flat areas where I can just hold the peddle full speed and it increases. Have several pics and tried several ways to reduce size but not getting past 97.7and I have 97.9kb

So much for pics it just not worth the trouble to try to reduce anymore

In short, the belt is a double V which is molded together similar to a serpentine but with larger V's. I might be able to cut the belt into 2 belts down the middle and get more from it, but my plan is now to measure the current belt. Then try to find 2 single belts to replace it with

I have a 20+ year old Hustler mower and its still on the same belt, and I have cut this same acreage with it.

Just poor design

 

[AllDodge]

Trying one pic after return and before cleaning up. Did measure the temp pully's and the outside was 140 to 148 degrees on the out side ones. The gear case was 152 and the idler pulley was 130. This was after about 10 minutes of traveling from mowing site to home and uncovering belt

 

[AllDodge]

More investigation leads to its not the belt. Trans is about a little low and motor oil is over full. The trans may be from time but the motor is way to high. Its either diesel, hyd fluid or both. With it being this high, I'm leaning toward injection pump leaking.

Headed to Barlow

 

[lugbolt]

Those double vee belts last a LONG time. Even if the backing comes off and they become two separate belts, they will still cut grass. Mine is also original, 30 years old. But it (the belt) also doesn't have to endure the same type of loading as your old Hustler. Completely different application. Reminds me, we started selling Hustler at work. I am NOWHERE near impressed with them. I'd just as soon buy a Murray than a Hustler as the quality is about the same.

 

[AllDodge]

I'd just as soon buy a Murray than a Hustler as the quality is about the same.

Thanks, that's a good one

The hustler of 20 years ago is not the same as the new one's. Your comment was still funny

 

[AllDodge]

Barlow has had it for over 2 weeks and they don't know what the problem is. Said they cut some grass and it didn't do it. I said I'll come out and cut the grass and when it starts doing it, how can you tell where its coming from?

The mower has to be shut down to look, no one is going to be looking while its running. Said they will get someone to clean it all up and give me a call to come out and cut grass, this was yesterday.

Today about lunch time I call and have not had time to clean it up. I know I don't buy enough to be any kind of priority, but I need the mower.

Think I'm on the "when they have nothing else to do" work time. Might have to go get it and fix it my self

 

[AllDodge]

Forgot about this thread but will close it out.

I went out and cut grass with it and it never put out the black as before. When finished and figured its not going to do it I talked to a young mechanic standing by the machine. He was the one which power washed and also cut some grass trying to see if it would show up.

He lifted the lid and checked the oil, then grabbed the breather and pulled it straight up and off. I didn't know it would lift off, I always lifted the soft rubber top to add any oil. He and I discussed and think we figured what happened.

The breather has nothing to hold it in place except just friction. Bouncing around on the mower the breather starts to lift up but does not come off because the metal lid over the top. The lid keeps it just so its bearly touching, so lube leaks out and gets blown over the deck.

I now push down on the breather before every cut and it has not done it since

 

[SDT]

Those double vee belts last a LONG time. Even if the backing comes off and they become two separate belts, they will still cut grass. Mine is also original, 30 years old. But it (the belt) also doesn't have to endure the same type of loading as your old Hustler. Completely different application. Reminds me, we started selling Hustler at work. I am NOWHERE near impressed with them. I'd just as soon buy a Murray than a Hustler as the quality is about the same.

Bingo.

I changed the double V belt on my B1750 with 60" MMM after 17 years when I needed to change a spindle bearing.

The belt was fine but I changed it because I had it off. Kept it for a spare and still have it after another 10 years or so.

SDT