John Deere X304

Ken Hopkins · Oct 14, 2024

Always serviced properly.
4 wheel steering
1177 hours
Threw a belt or broke belt, had it serviced while being repaired. Belt replaced. Used it 2 hours, broke belt again, replaced 2nd belt with instructions to check blade spindles. used it 2 more hours, broke belt again. Independent repair shop. Belts were not OEM John Deere belts.

What is my problem?

Patches · Oct 14, 2024

Think you answered your question; I've found OEM equipment superior to aftermarket???

tomplum · Oct 15, 2024

You didn't say what belt. Traction belt? Deck belt? 42" decks have had several issues, but it depends on which build you have.

Spanner · Oct 15, 2024

Ken Hopkins said:
...broke belt again, replaced 2nd belt with instructions to check blade spindles. used it 2 more hours, broke belt again. Independent repair shop. Belts were not OEM John Deere belts.

What is my problem?

Tom - I took the "...instructions to check spindles." to imply he's talking about the mower deck belt.

I agree you that there have been issues with belts on the 42" decks, especially the single belt configuration.
Mostly mis-routing in my experience. Belt guides not installed correctly and worn bearings in idlers and spindles.
Deck cracking and allowing movement of the rear-most central idler under tension is another instance of belt failure.

Patches is correct in his assessment that OEM belts are better than non-OEM on these mowers (IMO)

Ken: did you check (and grease) the spindles ?
Check the idlers for noisy bearings?
Check the belt guides for correct orientation?

tomplum · Oct 17, 2024

Spanner said:
Tom - I took the "...instructions to check spindles." to imply he's talking about the mower deck belt.

I agree you that there have been issues with belts on the 42" decks, especially the single belt configuration.
Mostly mis-routing in my experience. Belt guides not installed correctly and worn bearings in idlers and spindles.
Deck cracking and allowing movement of the rear-most central idler under tension is another instance of belt failure.

Patches is correct in his assessment that OEM belts are better than non-OEM on these mowers (IMO)

Ken: did you check (and grease) the spindles ?
Check the idlers for noisy bearings?
Check the belt guides for correct orientation?

What I've found to be the main culprit on many with belt problems is wear in the tensioner arm @ the pivot. The OPs unit could be an earlier build that had old tensioner and guide set up. The ones with the tensioner handle have the guide set up both on the tension arm and behind the large flat idler. These seem to go longer w/o issue. It's the later ones that Deere "improved" that the guides were removed. Many of these have issues 400 hours+, if they didn't have them from new. But they have a bulletin that covers adding the special rear guide and hardware for a ridiculous sum for doing so. FYI, you can get the replacement arms aftermarket and they work just fine.
Notice how the design of the new belts are shaped a bit more like the Accel 42? Enough to where they fit down in the pulley more. A thinner belt is a poor man's way to buy a little more time on these. At least until they snap again.