z-truck roller bearings

[Gunner]

I lost a bit out of the QC. Now the z-truck is loose. Can I use a mini-torch to loosen the screws for the bearings or do I have to drill them out and replace them as it says in the manual ? As always, any help is appreciated.

[mtylerfl]

I lost a bit out of the QC. Now the z-truck is loose. Can I use a mini-torch to loosen the screws for the bearings or do I have to drill them out and replace them as it says in the manual ? As always, any help is appreciated.

The screws have permanent red loctite on them. Not sure if "torching" is safe for the surrounding components, but if you need to remove the screws, either heat or drilling off the heads would be required to get them out.

However...before you do all that...are you SURE you even need to remove the screws at all? Perhaps a bearing "jumped" the rails and all you need to do is readjust the adjustable bearings with a flat wrench to get the truck reseated properly.

[PCW]

My experience it is about a 50% ratio come loose with a #2 screwdriver. I would not heat the Z bearings. The screws are soft and could round out. I would try the screwdriver and flat wrench first and if that fails bring out the drill.:D

[Gunner]

I have a jewlers torch and I just want to heat up the screw.I want to break the locktite loose, so that I can loosen the screw.I still have to adjust the cam on the bearings. I will let you guys know how it works. Thanks for your help. I think Al described how to do this a couple of years ago. But I can't find the link. Thanks all for your help.

[Digitalwoodshop]

As you look at the Z from the front, the Z Roller Bearings on the left have a center drilled screw hole. The bearings on the right are off set drilled so they act like a cam to crimp down on the round rails.

To remove the bearing since they use soft screws, you always need to use a very good #2 Phillips. You hold the screw head and using a thin 13 mm wrench turn the bearing nut clockwise or down to loosen it.

It depends if LHR has installed red forever lock tite on the truck, but if the machine is new and never saw the LHR shop it will most likely have blue removable lock tite on it. Heating the screw is a good idea.... In picture 1 you can see where I did not get it hot enough and snapped the screw off.

So now for the trick to installing and adjusting it...

I find the nut flat closest to the hole drilled and threaded and dab it with nail polish.... This lets you see the flat that must be facing the outside when you are done. This lets you have the bearing at the most closed position holding the truck in place.

So I snug the screw of the bearing up with a wrench on it with the red flat out. Turn the wrench 1/8 of a turn CW to loosen it, re snug the screw then HOLD the screw and turn the nut CCW to tighten it up.

The trick is SNUG not SNAP.... Ask my if I know what SNAP feels like....:-(

Good Luck....

You might just find if you get a 13 mm bike wrench that you can slowly snug it letting the philips screw slide with the bearing.... This will re snug the bearing until you can order a few extra bearings and SCREWS.....

OR check your big BOX store for Metric Screws after you snap the bearing off...

O'.... If the Left Bearing is loose then you must remove the truck to tighten it....

Picture 2 is just showing the off set drilled hole on the Y bearing.... The arrow was for another post about Y Screws holding the belt.

Take special note of picture 4 of the lower right Z Truck Screw MISSING the black washer.... This is a very OLD picture from the first year.... IF ANYONE has a Z Truck that has the Holes for the Probe and Sensor and is the OLD Version of the Z Truck you NEED a Washer like in picture. Picture 3 shows the Washer.....

New Castings of the Z Truck that DO NOT have the holes for the old Probe Jack have THICKER Metal Castings and don't need the washer. The Early Truck Castings had a bad habit of cracking the screw hole due to the Wedge of the Screw Head...

OK... TMI.... Too much Info.... But a Good Review of Truck problems....

AL

[Gunner]

Thanks Al, I knew you would have the information that I needed.