Track tensioner repair

[elkjunkie]

This tb135 tensioner would bleed down in 5 minutes. The o-ring was badly scarred and the back-up ring was half gone. The outer seal was installed lip out (backwards I think).
The piston was pitted from previous water damage. My plan is to braze the pitted ring and reinstall with new seals.
My brazing skills need improvement. I could still-
1) JB weld the remaining pitting
2) attempt to braze again
3) grind off, weld, and pay for turning
4) buy a new piston for $95
5) call it good and put it together

 

[Bluox]

Can you turn the slug around and use the other end?
Bob

 

[elkjunkie]

Unfortunately one end of the piston has a cavity for the idler rod and spring assembly. If I had a drill press maybe. The metal seems pretty hard though.
Thanks for the idea

 

[RZucker]

The outer seal should be lip out, it's there to exclude dirt. $95 bucks for a new piston seems reasonable to me, I doubt a machine shop would spray weld and refinish for that price.

 

[elkjunkie]

Dammit.... thanks RZ I guess I put the seal in wrong. It is double lipped so I hope it lasts a while. I will have to pull the track and motor again as I couldn't figure out my 2-speed problem and the idler fork on that side is cracked and spread around a half inch. I'm going to limp it along and do some adjusting and welding when winter hits. The track adjuster held for 4-5 hours yesterday.

 

[elkjunkie]

Finally got around to the other tensioner. This one wasn't nearly as problematic. The outer seal was installed "lip in" and I haven't been able to find a definitive answer on the proper install other than RZ's which sounded logical. No pitting on this one so a new o-ring and back-up ring replacement should do the trick.
BTW the other tensioner is still holding well.