I have a Nordictrack E5.7 and the right roller will come off of track after about 10 min off use.

The answer is yes you need a key. You also seriously need to read the manual before you use this machine.
https://www.manualowl.com/m/NordicTrack/C-1800s/Manual/341906
and this one for why and what could possibly go wrong - for your entertainment.
https://www.youtube.com/watch?v=qNPhVVjnoC0

the only lubrication that needs done is between the walking belt and the deck. if a roller is squeaking either front or rear you can try using wd40 on the bearings on either side

You don't oil belts as oil will eat away at the rubber. Start with running the machine and checking for lumps of wax build up at rollers (most common issue) if this is not it try oiling roller bearings. But call manufacturer first to see if your warranty is still good because as soon as you touch it it will void warranty.

you need the tread belt,https://www.fitnessrepairparts.com/equipment/Select/239/NordicTrack/EXP-2000-NTTL11990

Hello.
Knocking noises more than likely come from the rear roller, there could be a small chance it's coming from the motor it's self though.
Have some walk on the machine and make the noise while you locate which end of the treadmills coming from.

If it is the rear roller the bearings will need to be replaced, this can be done by removing the rear roller and taking it down to any bearing shop and have them locate the bearing numbers. Ask them for advise on removing them as well.

If the noise is coming from the front of the treadmill then have a look at the fly wheel coming off the motor, locate grub screws and tighten.

GymWorld.net.au

With regard to the clunking in the NordicTrack E7sv it turned out to be the left side wheel to crankshaft connection. It had come loose. I removed the left side foot rods and wheel cover plate for access. I re-seated the wheel on the shaft and tightened the hardware. Noise gone. So is all the squeaking associated with it loosening.

see the video and proceed according. God bless you

Step 1:

please see the video and diagram attached. God bless you

Step 2:

Step 3:

if it is moving to the right you must tighten the right side of the rear roller

you are doing wrong side

Hello, Yes you have a bad bearing. The bearings are not replacable on the rollers. You will need to replace the whole roller.


Matt

If you need further help, I’m available over the phone at https://www.6ya.com/expert/matt_8dbc24bf722649ac