Lose Z Truck

[Shacky]

I noticed that there is a lot of play in my Z truck moving away from the Y truck off the rails. I have found that the bottom seems ok, but the top is lose. The screw on the top left bearing is lose but it won't loosen or tighten. I am going to go buy a 12mm flat wrench tomorrow and see if I can take out the play by turning the top right bearing to tighten the fit.

I'm just wondering if anyone has any input. Am I on the right track?

[Mugsowner]

The issue you most likely got going is, when screws were installed they had Loctite on them. Loctite can free up with heat, but can reset after it cools sometimes, which is what I think you have here. I have seen it on my machines. I use a small butane torch to heat the screw until it frees up. Around 250 deg most thread lockers break down and let go. The 12 mm wrench will need to be ground down to the narrow width of the nut on the bearing. If you have an old flat wrench from a router or other tool with like flat wrench that has a smaller opening can be ground open easily.

[Mugsowner]

I should add that the bearing may be bad. I am not sure what caused the bearing to come loose. Being heat has effects on the thread locker, I would be looking at the bearing to see if it made the heat.

[Shacky]

Thanks for your thoughts. The bearings seem to spin freely. I do have an extra set, but it looks like a pretty big job to install. The top left bearing screw will turn but not tighten or loosen, but it seems like there is no play in that bearing, so it seems ok except for being able to turn the screw. As you know, the right bearing tightens the truck on the rails by rotating the nut. I guess my first attempted fix will be to get a flat wrench and see if I can turn that and if it tightens it up.

[cestout]

Doesn't LHR still sell that wrench? Order that and a new adjustable and a non-adjustable roller. They fit the T and Z trucks. I keep them on hand because of Murphy's Law. Haven't used them in the 6 or7 years I have had them. Keep the rollers lubed with WD40. Since I switched to that several years ago I have had not problems with any roller. I now also use it on the posts and jack screws because it doesn't collect the saw dust.
Clint