track keeps coming loose on deere 490

[Canaan_Realian]

Fighting with a John Deere 490 and the track tensioner's driving me nuts. Won't hold tension, track keeps coming loose, and sometimes it even runs right off. Pulled the thing apart and, no surprise, the end cap was practically falling off... two bolts gone, seals shot.

I've got a seal kit on order, but honestly, this design feels like it's asking for trouble. You'd think Deere could build something that stays together without constant babysitting. Anyone here had luck resealing one of these Fabtek tensioners and getting it to hold up? Or am I just signing up for a recurring battle no matter what?

 

[beauxboo]

wear on the mounting hole and the broken seals are a pretty clear indication of a failure that was happening over time. The Fabtek tensioner design's constant stress and vibration can eventually cause metal to fatigue and wear. The good news is that with the new seal kit and the prop balance, you should have a more reliable system. You've done a good job by fixing the worn mounting hole and restoring the seals.

 

[logged in]

Check the cylinder bore for wear too, good reseal can help, but if the bore is scored or the threads are tired, it’ll keep bleeding off no matter what or maybe you could add thread locker or slightly longer bolts to keep the cap from backing out

 

[TheWoodPecker]

@Canaan_Realian if the piston bore is even a little scored, the new seals won’t last long. Make sure you chase the threads and use thread locker on the cap bolts